Id	Category	Example	Reporting	Details
1	Injury or Fatality	An operator walks through a process unit and slips and falls to the ground and suffers in an occupational injury, which is a lost work day case (LWDC). The slip/fall is due to weather conditions, ‘chronic’ oily floors, and slippery shoes. This is not a Tier 1 or Tier 2 PSE. Personal safety ‘slip/trip/fall’ incidents that are not directly associated with evacuating from or responding to a LOPC are specifically excluded. LWDC but not a PSE Same as above, except that the operator slips and falls while responding to a small spill of liquid with a flash point <23 °C (73 °F) quantity less than 7 barrels in 1 hour, resulting in a recordable LWDC incident. This would also be recorded as a Tier 1 PSE since the operator is responding to an LOPC, even though the LOPC is below the Tier 1 threshold quantity in Table E.4. Tier 1 PSE and a LWDC Same as above, except that the operator slips and falls several hours after the incident has concluded. This is a recordable LWDC incident but would not be a reported as a PSE. Occupational safety events that are not directly associated with onsite response to a LOPC are excluded. A slip or fall after the LOPC has concluded (such as ‘after-the-fact’ clean-up and remediation) is not directly associated with onsite response LWDC but not a PSE		View
2	Injury or Fatality	A scaffolding contractor is injured after falling from a scaffold ladder while evacuating from a LOPC on nearby equipment. The contractor is absent from work for 5 days and the injury is recorded as a recordable LWDC incident and the LOPC is then classified as a Tier 1 PSE, whether or not the release exceeded the Table E.1 Threshold quantities. Tier 1 PSE and a LWDC		View
3	Injury or Fatality	An operator walks past a steam trap that discharges to an unsafe location. The steam trap releases and the operator’s ankle is burned by the steam, resulting in an occupational injury which needed medical treatment and his work is restricted for 3 days. This incident is a Tier 2 PSE, because even though the LOPC event was steam (vs. hydrocarbon or chemical), the physical state of the material was such that the unintended release caused a recordable injury. Non-toxic and non-flammable materials are within the PSE scope when a recordable injury results from LOPC. Tier 2 PSE and RWDC If this incident had not resulted in an occupational injury it would not be a PSE because the physical state of the material does not mandate a Tier 1 or Tier 2 classification without the associated recordable injury. Not a Tier 1 or Tier 2 PSE		View
4	Injury or Fatality	A separator chamber or other vessel has been intentionally purged with nitrogen. A contractor bypasses safety controls, enters the enclosure and dies. This is not a PSE because there is no unplanned or uncontrolled LOPCs, but it would be a recordable occupational injury and classified as a contractor employee fatality. Fatality but not a Tier 1 or Tier 2 PSE If nitrogen had inadvertently leaked into the enclosure, this would be a Tier 1 PSE because there was a fatality associated with an unplanned or uncontrolled LOPC. Tier 1 PSE and a fatality		View
5	Injury or Fatality	A maintenance technician is turning a bolt on a flange on a gas pipe with a wrench. Due to improper body positioning, the wrench slips and hits the employee in the mouth, requiring dental surgery. This incident is a recordable occupational injury (medical treatment case) but not a PSE, because there is no unplanned or uncontrolled LOPC involved with the injury. Recordable injury but not a Tier 1 or Tier 2 PSE		View
6	Injury or Fatality	A maintenance contractor opens a process valve and gets sprayed with less than the Tier 2 Threshold Quantity of sulfuric acid resulting in severe burn and days away from work injury. This is a Tier 1 PSE because it is an unplanned or uncontrolled LOPC that results in a lost work day case (LWDC). Tier 1 PSE (Table E.1) and a LWDC If this incident had resulted in a recordable injury which was not a LWDC or fatality (i.e., a restricted work day case or a medical treatment case), it would be a Tier 2 PSE. Tier 2 PSE (Table E.1) and a recordable injury		View
7	Injury or Fatality	During the draining of a produced water line, the drain valve failed to open, resulting in a significant release. While responding to the event the operator fell down a flight of stairs injuring his ankle. The injury resulted in 8 days away from work. This is a Tier 1 PSE because an unplanned or uncontrolled LOPC resulted in a lost work day case (LWDC). Tier 1 PSE (Table E.1) and a LWDC		View
8	Fire or Explosion	Over-pressurisation in a process vessel causes equipment damage greater than $100,000, but there was no loss of primary containment. While this is a serious process event and should be investigated as such, it does not meet the definition of a Tier 1 or 2 PSE because there was no LOPC involved.It is good practice to report, classify, and investigate other types of asset integrity or process events with actual or potentially serious consequences using the internal reporting mechanisms of the company and its facilities. This would include locally defined possible Tier 3 PSE KPIs. Not a Tier 1 or Tier 2 PSE Possible Tier 3 PSE KPI		View
9	Fire or Explosion	A scaffold board is placed near a high-pressure steam pipe and subsequently begins to burn, but is quickly extinguished with no further damage. The investigation finds that the board had been contaminated by oil, but there is no indication of an oil leak in the area. This is not a PSE since there was no unplanned or uncontrolled LOPC, but may be a reportable incident under other company or facility KPIs Not a Tier 1 or Tier 2 PSE		View
10	Fire or Explosion	An electrical fire impacts the operation of the process resulting in an acute release outdoors of 3,300 lbs. (1500 kg or about 10 bbl) of light crude oil (API Gravity ca. 40, flash point <23 °C). The released crude oil is not ignited. This is a Tier 1 PSE since the released crude oil did not ignite and the LOPC exceeds the reporting threshold quantity of 2,200 lbs. (1000 kg, 7bbl) for a flammable liquid. NOTE: If the crude oil had ignited, the amount of the release would no longer be relevant and only the direct damage cost of the crude oil fire would have been used to determine the Tier level. Tier 1 PSE (Tables E.2 & E.4)		View
11	Fire or Explosion	An electrical fire results in a sudden loss of power that causes an emergency shutdown and incidental equipment damage greater than $100,000 to the oily water separator due to inadequate shutdown. Since the event did not result in LOPC of a material, it is not a PSE, but is likely to be reportable based on other KPIs of the company or facility Not a Tier 1 or Tier 2 PSE		View
12	Fire or Explosion	A pump lube oil system fire from a leak causes damage greater than $75,000 and the soil remediation and other cleanup costs are $50,000, but does not cause a fatality or serious injury. This is a Tier 1 PSE since the direct costs to the company because of the fire was greater than $100,000. Tier 1 PSE (Table E.1)		View
13	Fire or Explosion	A forklift truck moving materials inside a process unit knocks off a bleeder valve leading to the release of condensate and a subsequent vapour cloud explosion with asset damage and clean-up costs greater than $100,000. This is a Tier 1 PSE since an unplanned or uncontrolled LOPC resulted in a fire or explosion causing greater than $100,000 direct costs to the company. Tier 1 PSE (Table E.1)		View
14	Fire or Explosion	There is a boiler fire at the main office complex, and direct cost damages totaled $150,000. The incident is not a PSE since office, shop, warehouse, and camp/compound building events are specifically excluded, but is likely to be reportable based on other KPIs of the company or facility. Not a Tier 1 or Tier 2 PSE		View
15	Fire or Explosion	Hydrocarbon fumes migrate into the QA/QC laboratory located within the facility and results in a fire with $5,000 damage. The source of the hydrocarbon fumes is the oily water sewer system. This event is a Tier 2 PSE since the LOPC was from the process and resulted in a Tier 2 consequence (a fire which results in a direct cost greater than $2,500). Tier 2 PSE (Table E.1)		View
16	Fire or Explosion	A pump seal fails and the resultant loss of containment catches on fire. The fire is put out quickly with no personnel injuries. However, the fire resulted in the need to repair some damaged instrumentation and replace some insulation. The cost of inspection to determine the extent of the damage and the necessary repairs totaled $8,500. The cost of the repairs, replacement, and cleanup totaled $20,000. Is this a Tier 1 or Tier 2 PSE? This is a Tier 2 PSE since the direct costs from the fire damage exceeded the Tier 2 threshold of $2,500 but was less than the Tier 1 threshold of $100,000. It should be noted the cost of replacing the seal is not included in the direct cost calculation—only the costs for repair and replacement of the equipment damaged by the fire, not the cost to repair the equipment failure that led to the fire. Also excluded from the direct cost calculation is the cost for engineering or inspection assessments to determine the extent of damage or necessary repairs. Tier 2 PSE (Table E.1)		View
17	Fire or Explosion	There is a loss of burner flame in a fired heater, resulting in a fuel rich environment and subsequent explosion with greater than $100,000 in damages to the interior of the heater. There was no release outside of the fire box. After the flameout the continuing flow of fuel gas results in an uncontrolled release; however, because the explosion resulted in direct cost greater than $100,000, the amount of the release need not be considered. The intent is for combustion of the fuel gas at the burner and not for fuel gas to be contained in the fire box. This is an LOPC and due to the amount of direct cost would be a Tier 1 PSE. Tier 1 PSE (Table E.1) If this same incident had resulted in less than $100,000 but over $2,500 in damages, it would be a Tier 2 PSE. Tier 2 PSE (Table E.1)		View
18	Fire or Explosion	A tube rupture in a fired heater causes a fire (contained in the heater) resulting in greater than $100,000 in damages to the heater interior. The tube failure is a loss of primary containment of the process fluid and combined with the direct costs greater than $100,000, makes this a Tier 1 PSE. Tier 1 PSE (Table E.1) Same as above, except the operator detects the tube cracking with only a small flame from the tube and subsequently shuts down the heater with no resultant damage from the tube flame. If the estimated amount of material released is below the threshold quantities in Table E.4, E.5, or E.6, this would not be a Tier 1 or 2 PSE. However, this event could be reported within the Tier 3 PSE KPI of the company or facility. Possible Tier 3 KPI		View
19	Fire or Explosion	A steam injection well fails with an explosion resulting in release of 10 tonnes of fluids (a mixture of hydrocarbons and water). The direct cost of replacing and repairing damaged equipment was estimated at $300,000 and a worker was injured, needing medical treatment. The failure is a Tier 1 Process Safety Event, because it is an LOPC that resulted in an explosion causing over $100,000 of damages. Tier 1 PSE (Table E.1) and a recordable injury As above, but without the explosion. The recordable injury resulting from the LOPC would require at least a Tier 2 PSE be reported. Tier 1 PSE (Tables E.2 & E.4) or Tier 2 PSE (Table E.1) and a recordable injury		View
20	Fire or Explosion	A line catastrophically fails due to vibration induced fatigue. The release ignites resulting in a jet fire. The jet fire impinges on a crane parked nearby destroying the crane but does not cause any significant damage to process equipment. The cost to replace the crane is $350,000. This is a Tier 1 PSE since the direct cost fire damage from the LOPC exceeded the Tier 1 PSE threshold of $100,000. By definition, direct cost fire/explosion damage includes the cost to repair or replace process and non-process equipment and tangible public or private property. Tier 1 PSE (Table E.1)		View
21	Fire or Explosion	A corrosion related leak results in a large fire that damaged piping and an out-of-service vessel (abandoned in place). The company spends $15,000 in engineering and inspection costs to determine the extent of the fire damage, $95,000 to replace the damaged pipework with an upgraded metallurgy resistant to the corrosion damage mechanism, and $50,000 to make the out-of-service vessel safe to remain in place. To replace the pipework with in-kind metallurgy would have cost $45,000. To restore the functionality of the out-of-service (abandoned in place) vessel would have cost $125,000.This is a Tier 2 PSE. The definition of direct cost excludes the cost of engineering or inspection assessments to determine the extent of damage or necessary repairs, and it also excludes the cost of opportunity upgrades to materials or technology. The definition of direct cost does include the cost to restore equipment to pre-event condition whether or not the repairs are made. In this example the out-of-service vessel has been abandoned in place (i.e. no expectation of future functionality); therefore, only the post fire cost to make the equipment safe is included in the direct cost calculation. This is a Tier 2 PSE based upon $50,000 to make the vessel safe and $45,000 for the in-kind metallurgy piping replacement for a total direct cost of $95,000. Tier 2 PSE (Table E.1)		View
22	Fire or Explosion	A portable diesel-driven pump was being used to transfer material from one tank to another. The hot exhaust of the diesel engine ignited a fire in the soundproofing exhaust housing and burned through a radiator hose releasing engine coolant. The fire damage to the pump exceeded $2500. Not a Tier 1 or Tier 2 PSE This is not a Tier 2 PSE. While the temporary portable pump and its diesel-driven engine is part of the process while it is connected to the process, the fire was caused by the hot exhaust and not a LOPC, therefore, the fire damage is excluded from the Tier 2 determination. Additionally, the fire induced LOPC of engine coolant did not result in any of the Tier 2 consequences. A company may choose to record this event as a Tier 3 PSE KPI fire. Possible Tier 3 PSE KPI		View
23	Fire or Explosion	A crude oil liquid carryover to the flare resulted in a fire at the base of the flare and the unignited crude oil contaminated the soil surrounding the flare. The liquid carryover quantity released in any one hour was minimal and below Tier 1 and Tier 2 thresholds and the fire did not result in any equipment damage that required repair. However, the cost to remediate the contaminated soil was $3,800.This is a Tier 2 PSE since the direct cost to the company associated with the flare carryover fire was >$2,500 because the soil remediation clean-up cost is included in the fire direct cost calculation. Tier 2 PSE (Table E.1)		View
24	Loss of primary containment	Ten barrels of flammable condensate (1,400 kg, 3,100 lbs) leak from piping onto concrete and the hydrocarbons do not reach soil or water. Site personnel estimate that the leak occurred within one hour. This is a Tier 1 PSE because there was a LOPC of 7 bbl (1,000 kg, 2,200 lbs.) or more of flammable liquid with a flash point <23 °C (73 °F) in any one-hour period. Tier 1 PSE (Tables E.2 & E.4) If the spill had been less than 1,000kg/2,200 lbs., but equal to or greater than 220 lbs (0.7 bbl), it would be a Tier 2 PSE. Tier 2 PSE (Tables E.2 & E.4)		View
25	Loss of primary containment	A faulty tank gauge results in the overfilling of a product tank containing liquid with a normal boiling point > 35 °C (95 °F) and a flash point < 23 °C (73 °F). Approximately 50 barrels (7,000 kg/15,500 lbs.) of liquid overflows into the tank’s diked area within minutes. This event is a Tier 1 PSE since it is a release of 2,200 lbs. (1000 kg/7 bbl) or more within any one-hour period, regardless of secondary containment. Tier 1 PSE (Tables E.2 & E.4) If the spill had been less than 2,200 lbs. (1000 kg/7 bbl), but equal to or greater than 220 lbs. (100 kg/0.7 bbl), it would be a Tier 2 PSE. Tier 2 PSE (Tables E.2 & E.4)		View
26	Loss of primary containment	A process vessel low level cutout fails to close a valve, releasing 1200 lbs. of flammable gas, causing minor damage to a tank and a gas release to the atmosphere. This was an LOPC from the vessel and because the amount exceeds the 1100 lbs. threshold quantity for flammable gas, this is a Tier 1 PSE. Tier 1 PSE (Tables E.2 & E.4)		View
27	Loss of primary containment	An operator opens a quality control sample point to collect a routine sample of crude oil and material splashes on him. The operator runs to a safety shower leaving the sample point open and a Tier 2 threshold quantity is released. This is a Tier 2 PSE since the release of a threshold quantity was unplanned or uncontrolled. Tier 2 PSE (Tables E.2 & E.4) Same as above, however, the operator catches the sample, blocks in the sample point, and later drops and breaks the sample container resulting in exposure and injury from the sample contents. This is not a PSE because the LOPC is from a piece of ancillary equipment not connected to a process. Not a Tier 1 or Tier 2 PSE		View
28	Loss of primary containment	A bleeder valve is left open after a plant turnaround. On startup, an estimated 15 bbl of lubricating oil with a flashpoint of 195 °C (383 °F), is released at 38 °C (100 °F) onto the ground within an hour and into the plant’s drainage system before the bleeder is found and closed. This is not a Tier 1 or Tier 2 because the flash point is higher than 93 °C and it is released at a temperature below its flash point. It can be reported as Tier 3 PSE KPI. Possible Tier 3 PSE KPI (Tables E.2 & E.4) Same as above, except that the release temperature is above the flashpoint; thus, it would be a Tier 1 PSE. Tier 1 PSE (Tables E.2 & E.4)		View
29	Loss of primary containment	An operator is draining water off a crude oil tank with a flash point of 60 °C (140 °F) or less (or an API Gravity of <15) into a drainage system designed for that purpose. The operator leaves the site and forgets to close the valve. Twenty barrels of crude oil are released into the drainage system within an hour. This would be a Tier 1 PSE because the release of crude oil is unplanned or uncontrolled and it is greater than the release criteria of 14 barrels.If the drainage system is a closed system and goes to an API separator and the oil is recovered (secondary containment), this would not be a Tier 1 event because the crude oil did not leave primary containment. If the closed drainage system is breached, ineffective, or overwhelmed, then the amount of oil lost from the closed system would be evaluated for a possible Tier 1 or Tier 2 event. Tier 1 PSE (Tables E.2 & E.4) In the example above, if a crude oil with a flash point above 60 °C (140 °F) and less than 93 °C (200 °F) is released at a temperature below the flash point, it would be a Tier 2 PSE. Tier 2 PSE (Tables E.2 & E.4)		View
30	Loss of primary containment	An operator purposely drains 20 bbl of material with a flash point >60 °C (140 °F) ≤ 93°C (200 °F) at a temperature below its flash point into an open oily water collection system within one hour as part of a vessel cleaning operation. Since the drainage is planned and controlled and the collection system is designed for such service, this is not a reportable Tier 1 or 2 PSE. Not a Tier 1 or Tier 2 PSE If the material released had been unplanned or uncontrolled and flowed to an open drain, sewer or other collection system, it would be a reportable Tier 2 PSE based on the threshold quantity and material below its flash point. Tier 2 PSE (Table E.2 & E.4)		View
31	Loss of primary containment	A valve leak occurred in a gas turbine acoustic enclosure (or a valve box) which is accessible to the workforce. The quantity of natural gas released was 40 kg within 1 hour. This is a Tier 2 PSE, because the LOPC exceeds the threshold quantity for an indoor release of flammable gas. If equipment or a work area is enclosed (apart from louvers and/or air intakes) then the indoor release threshold quantities should be used for determining whether an LOPC occurring in any one-hour period is a Tier 1 or Tier 2 PSE. Tier 2 PSE (Tables E.2 & E.4)		View
32	Loss of primary containment	An operator finds a leaking natural gas pipeline while making his normal rounds. It takes him 15 minutes to isolate the pipeline. During the 15 minutes it takes to isolate the pipeline, 20 kg (44 lbs.) of natural gas is released. Then it takes 90 minutes to depressurize the pipeline through the leak point (there was no other means to blowdown the pipeline). The maximum amount released in any 1 hour period during isolation and blowdown is 60 kg. The blowdown of the line is included in the LOPC threshold quantity. This is a Tier 2 PSE because the release rate exceeds the threshold quantity of 50 kg (110 lbs.) in any 1 hour period. Tier 2 PSE (Tables E.2 & E.4) Same as above but, the natural gas release rate does not exceed 50 kg (110 lbs.) in any given 1 hour time period during isolation and blowdown. Not a Tier 1 or Tier 2 PSE Possible Tier 3 PSE KPI		View
33	Loss of primary containment	A process upset leads to gross crude oil contamination of the produced water stream that is being discharged to sea. The contamination lasts for several hours and the largest quantity of oil released to sea in any one hour is 4000kg.In addition, determination of a PSE is not dependent on the environment into which the LOPC occurs. The acute discharge quantity exceeds the Tier 1 PSE release threshold for this crude oil which has flash point <60 °C (140 °F). Tier 1 PSE (Tables E.2 & E.4)		View
34	Loss of primary containment	A process overpressure leads to a pipeline failure causing LOPC from three different points. The released material is a flammable liquid with boiling point ≤35 °C and flash point <23 °C. It takes 90 minutes to stop the leak and the maximum released amount in any hour for each point is: 26 kg from the first release point which is a hole of 0.5 mm diameter, 101 kg from the second point which is a hole of 1 mm diameter, and lastly 406 kg from a flange joint.This is a single Tier 1 LOPC as there are multiple releases caused by a single initiating event and total released amount is 533 kg which is higher than Tier 1 threshold (500 kg for outdoor release). Although the first release is below the Tier 2 threshold and the second/third releases below the Tier 1 threshold, the PSE classification is based on the total released amount from all release points combined, which is 533 kg. Tier 1 PSE (Tables E.2 & E.4)		View
35	Loss of primary containment	While doing routine well checks on a Normally Unmanned Installation (NUI), operator comes across a spill. The fluid was a flammable liquid with boiling point >35 °C and flash point <23 °C that was coming from a dust cap of a stuffing box. The maximum release rate was 384 kg in any hour.This is a Tier 2 PSE as the maximum released quantity in an hour is above the Tier 2 threshold for this material (100 kg for outdoor release). NUI is part of the process and consequently the releases from NUI are included in the scope of PSE reporting. Tier 2 PSE (Tables E.2 & E.4)		View
36	Loss of primary containment	An outdoor two-phase LOPC happened in production separation area. The two-phase release was released over a one hour period and was composed of:• 17 kg of natural gas, and• 89 kg of light crude oil, with Boiling Point >35 °C (95 °F) and Flash Point <23 °C (73 °F)To determine if this is a PSE the following analysis is made:• Flammable Gas (natural gas) released quantity (17 kg) is only 34% of the Tier 2 outdoor threshold ≥50 kg (110 lbs)), whereas• Flammable liquid (light crude oil) released quantity (89 kg) is only 89% of the Tier 2 outdoor threshold ≥100 kg (220 lbs).Applying the API RP 754 mixture principle for event classification, then 89% + 34 % = 123 % and thus the event is a Tier 2 PSE. Alternatively, another way to look at this case is to consider that there is a release of 106 kg of flammable gas/liquid mixture, which is greater than both Tier 2 threshold quantity for flammable gas and flammable liquid, and thus the event is a Tier 2 PSE. Tier 2 PSE (Tables E.2 & E.4)		View
37	Loss of primary containment	In an offshore platform a generator diesel pump began leaking after it was put in service. The generator provides electricity to run the production process, so it is considered “part of the process” for PSE determination. The calculated outdoor released quantity in an one hour period was 15 bbl of diesel with flash point less than 60°C (140°F). This event is classified as a Tier 1 PSE because the quantity released exceeded the Tier 1 outdoor threshold (14 bbl). Tier 1 PSE (Tables E.2 & E.4) The same as above but, the diesel has a flash point > 60°C (140 °F) and ≤ 93°C (200°F) and it is released at a temperature below its flash point. In this case the event is classified as a Tier 2 PSE because the quantity released exceed the Tier 2 outdoor threshold (7 bbl). Tier 2 PSE (Tables E.2 & E.4)		View
38	Loss of primary containment	An oily water leak occurred from an API Separator on an onshore well pad. The leak was caused by a hole on the feed line due to corrosion issues. The oily water released was a mixture of water (quantity of 850 kg) and hydrocarbons (quantity of 150 kg) with Boiling Point >35 °C (95 °F) and Flash Point <23 °C (73 °F)). The release was stopped in less than one hour.If the amount of hydrocarbon released met or exceeded any Tier 1 and Tier 2 thresholds in Table E.4, then a Tier 1 or Tier 2 PSE to be reported. The estimate of material released should exclude the amount of water, as there is no threshold quantity for water. In this case the hydrocarbons quantity exceeds the Tier 2 outdoor threshold and so the event is a Tier 2 PSE. Tier 2 PSE (Tables E.2 and E.4) As above, but with the quantity of water of 980 kg and the quantity of hydrocarbons of 20 kg. In this case the hydrocarbons quantity does not exceed the Tier 2 outdoor threshold and so the event can be recorded as possible Tier 3 PSE KPI. Possible Tier 3 PSE KPI		View
39	Loss of primary containment	Heat Exchanger Tube Leak Examples:There is a crude oil (15< API Gravity) leak into a cooling water system which is >2 bbl in a one hour period. This is considered an LOPC. The severity of the LOPC is considered the same as a release directly to the atmosphere. This would be a Tier 2 PSE since the release rate is above the outdoor release threshold rate. Tier 2 PSE (Tables E.2 & E.4) A vessel contains two phases—aqueous and non-aqueous. The aqueous phase overfilled the vessel, resulting in a carryover of corrosive material (>12.5 pH) into equipment that was not intended for that purpose. The overfill occurred for 30 minutes and a total of 1200 kg or 2400 lbs was released into the downstream equipment.The corrosive material carried over to equipment that was not designed to handle the material; therefore, this would be considered an LOPC. This would be a Tier 2 PSE since the material that carried over would be considered a strong base. Tier 2 PSE (Tables E.2 & E.4)		View
40	Acute release (within any one hour period)	There is a 10 bbl spill of condensate that steadily leaks from piping outdoor onto soil over a two-week time period. Simple calculations show the spill rate was approximately 0.03 bbl per hour. This is not a Tier 1 or Tier 2 PSE since the spill event did not exceed the threshold quantity in any one-hour period. However, this event can be reported within the Tier 3 KPIs of the company or facility. Possible Tier 3 PSE KPI Same example as above, except that the 10 bbl leak was estimated to have spilled at a steady rate over a period of 1 hour and 30 minutes. Simple calculations show that the spill rate was 6.7 bbl per hour. The spill rate was less than the reporting threshold of 7 bbl within 1 hour for a Tier 1 PSE but it does meet the threshold of 0.7 bbl within 1 hour, thus it is a Tier 2 PSE. Tier 2 PSE (Tables E.2 & E.4)		View
41	Acute release (within any one hour period)	An operator discovers an approximate 10 bbl liquid spill of light crude oil (flash point <23 °C, API Gravity >15) near a process exchanger that was not there during their last inspection round two hours earlier. Since the actual release duration is unknown, a best estimate should be used to determine if the Threshold Quantity rate has been exceeded (it is preferred to err on the side of inclusion rather than exclusion). This incident is a Tier 1 PSE because the crude oil involved is a flammable liquid and the threshold quantity of 7 barrels is exceeded if the time period is estimated to be less than one hour. Tier 1 PSE (Tables E.2 & E.4)		View
42	Acute release (within any one hour period)	Infrared scans identified that a separator floatation treater was leaking 10,000 SCFD (approximately 8 kg per hour) of gas from the agitator seals. The separator continued to operate for 10 days until the treater was taken out of service and its seals replaced. This LOPC is not a PSE because the leakage rate was less than the Tier 2 release threshold for flammable gas 50 kg (110 lbs) in one hour. Not a Tier 1 or Tier 2 PSE		View
43	Acute release (within any one hour period)	While troubleshooting an abnormally high natural gas flow rate, operating personnel find a safety valve on the natural gas line that did not reseat properly and was releasing to the atmospheric vent stack through a knock-out drum. Upon further investigation, it is determined that a total of 1 million lbs of natural gas was released at a steady rate over a 6-month period. This is an LOPC which does not meet the criteria for a Tier 1 or Tier 2 PSE and could be reported as a Tier 3 KPI by the company. Although the release rate is about 100 kg per hour and exceeds the threshold quantity of Tier 2, it does not result in one of the defined adverse consequences. Not a Tier 1 or Tier 2 PSE Possible Tier 3 PSE KPI		View
44	Acute release (within any one hour period)	A pipe containing CO2 and 10,000 vppm H2S (1% by volume) leaks and 7,000 kg (15,400 lbs) of the gas is released within an hour. Calculations show that the release involved about 55 kg (120 lbs) of H2S (TIH Zone B toxic hazardous material). The release is a Tier 1 PSE because it exceeded the threshold quantity. Tier 1 PSE (Tables E.2 & E.5) If the H2S concentration were 50 vppm, then the calculated release quantity would be 0.3 kg of H2S. The release would not be a Tier 1 or Tier 2 PSE since this amount is below the 25 kg (55 lbs) and 2.5 kg (5 lbs) thresholds for H2S. However, this LOPC event could be reported within the Tier 3 PSE KPIs of the company or facility. Possible Tier 3 PSE KPI		View
45	Acute release (within any one hour period)	There is an outdoor release of 4000 kg of Molten Sulphur below its flash point. Molten Sulphur is a Packing Group III, Hazard Class 9 material. This is not a Tier 1 or 2 PSE as Packing Group III materials that do not pose a process safety hazard (e.g., Hazard Class 9 materials) cannot be a Tier 1 or Tier 2 PSE based on the quantity of material released. However, this LOPC event could be reported within the Tier 3 KPIs of the company or facility. Possible Tier 3 PSE KPI (Table E.6 Note)		View
46	Acute release (within any one hour period)	A portion of methanol piping is being prepared for maintenance. The line is drained and isolation is verified. At some point prior to the first flange break, the line accumulated liquid due to a leaking valve. The volume of material that leaked back into the isolated line is greater than the Tier 2 threshold quantity in any one-hour period. Since there was no LOPC, this is not a Tier 2 PSE. The material remained within the piping designed to contain it. Not a Tier 1 or Tier 2 PSE If the flanges were opened by a pipefitter and 300 lbs methanol immediately leaked out of the pipe, it would be a Tier 2 PSE. Tier 2 PSE (Tables E.2 & E.4)		View
47	Acute release (within any one hour period)	If an internal or external floating roof partially sinks and material gets above it, but remains within the tank, is this a LOPC?Material on top of the floating roof is an LOPC. Material stored within a floating roof tank is expected to be inside the tank walls and beneath the floating roof.Depending upon the volume of material released, this may be a Tier 1 or Tier 2 PSE. Tier 1 or Tier 2 PSE		View
48	Acute release (within any one hour period)	A flash fire occurred during top loading crude oil l into a third-party carrier truck. The driver sitting on top of the truck compartment at the manhole per loading procedures suffered burns requiring hospitalization. No liquid spilled from the truck, and there was no significant damage to equipment. The fire may have started due to static ignition and/or switch loading. Vapors are expected to be present in normal top loading operations.This is a Tier 1 PSE. When the ignition occurred, the flame front inside the vessel expanded the gases in the vapor space causing them to exit the manway at a much faster rate (and much hotter) than what would be considered “normal operation”, and therefore it was an unplanned and uncontrolled release resulting in a 3rd party hospitalization. Also, top loading operations qualify as being connected to the process for the purpose of loading. Tier 1 PSE (Table E.1 LWDC)		View
49	Acute release (within any one hour period)	A pipe containing CO2 and 10,000 vppm H2S (1 % by volume) leaks and 7000 kg (15,400 lbs) of the gas is released within an hour. Calculations show that the release involved about 55 kg (121 lbs) of H2S, a TIH Zone B chemical, and 6945 kg (15,279 lbs) of CO2, a UNDG Class 2, Division 2.2 non-flammable, non-toxic gas. The release is a Tier 1 PSE because it exceeds the Tier 1 threshold quantity for both Release Category 2 and 7.Alternate Scenario:If the H2S concentration is 50 vppm, then the calculated release quantity would be 0.3 kg (0.66 lbs) of H2S and 6999 kg (15,398 lbs) of CO2. The release would still be a Tier 1 PSE since this Release Category 7 threshold quantity is exceeded even though the Release Category 2 quantity falls below the Tier 1 and Tier 2 thresholds for H2S. Tier 1 PSE (Tables E.2 & E.5 & E.6)		View
50	Acute release (within any one hour period)	During a turnaround, a Tier 2 threshold quantity of crude oil was spilled from a frac tank that had been used for equipment draining. At the time of the spill, the frac tank was in the process area awaiting transport to the disposal facility but was not connected to the process. Is this a Tier 2 PSE?This is not a Tier 2 PSE. The frac tank was not connected to the process but was instead awaiting transport for disposal or recycle. The frac tank had transitioned from being part of the process (while connected) to being in transportation mode. This example is analogous to the use of a vacuum truck to transport material that was not actively loading, discharging, or using its transfer pump. A company may choose to record this as a transportation event. Not a Tier 1 or Tier 2 PSE Instead of awaiting transport to a disposal facility, the frac tank was awaiting transport to a crude tank where the material could be recycled back into the process after the turnaround. In this situation, the frac tank would be considered on-site storage even though it was not connected to the process, and the LOPC would qualify as a Tier 2 PSE for the refinery. Tier 2 PSE (Tables E.2 & E.4)		View
51	Pressure relief device	There is a unit upset and the PRD opens to an atmospheric vent, resulting in a release of 300 lbs. of propane to the atmosphere with no adverse consequences. Is this a PSE? This is not a Tier 1 or Tier 2 PSE. Although the release volume exceeded the Tier 2 threshold quantity for propane, the PRD release did not result in one of the defined negative consequences, and it is not a Tier 2 PSE. A company may choose to count this as a Tier 3 demand on a safety system. Possible Tier 3 PSE KPI Alternate Scenario:Same as above, but there was a non-precautionary site shelter-in-place. This is a Tier 2 PSE because it exceeded the Tier 2 threshold quantity for propane and resulted in one of the defined PRD negative consequence. Tier 2 PSE (Tables E.3 & E.4)		View
52	Pressure relief device	A sour gas scrubber has a PRD that was identified in a recent Process Hazard Analysis (PHA) to be undersized. During normal operations, the scrubber becomes over-pressurized. A release of 60 pounds of H2S gas (TIH Zone B material) occurs through this PRD and is directed to the flare system over a period of 25 minutes. This would not be a Tier 1 or Tier 2 PSE, regardless of the PHA finding, so long as it did not result in a rainout, on-site shelter in place, public protective measure, or other indication of discharge to a potentially unsafe location (Table E.3). A company using a Tier 3 KPI to track demands on safety systems could report this event as an activation of a PRD resulting in a release to atmosphere via a destructive device. Possible Tier 3 PSE KPI		View
53	Pressure relief device	A relief valve operates and vents 250 kg of flammable gas directly to the atmosphere with a small rainout estimated at 10 kg of hydrocarbon. This is a Tier 2 PSE because there was a rainout and because the total mass released exceeds the threshold quantity (i.e., not just the mass of the liquid or the mass of the gas) and major component of the material is flammable gas. Tier 2 PSE (Tables E.3 & E.4)		View
54	Pressure relief device	There is a unit upset and the PRD fails to open, resulting in over-pressurization of the equipment and a 10-minute release of 2200 lbs/1000 kg of C3-C5 hydrocarbons from a leaking flange before it can be blocked in. This is a Tier 1 PSE. Tier 1 PSE (Tables E.2 & E.4)		View
55	Pressure relief device	The failure of a vapour recovery unit (single initiating event) results in over-pressurization of three tanks, which is relieved through the PRDs located on top of each tank. The release quantity from Tank #1 is 172kg of methane, from Tank #2 is 31 kg of H2S, and from Tank #3 is 404 kg of methane. None of the four consequences related to PRD discharges occurred for the releases from Tanks #1 and #2. The release from Tank #3 was to a potentially unsafe location.This is a Tier 2 LOPC incident as the discharge from Tank #3 exceeds the Tier 2 threshold and the release was to a potentially unsafe location. The material released from Tank #1 and #2 is not included in the overall release quantity used to categorize the event because the PRD discharge on those two tanks did not result in any of the four consequences. Tier 2 PSE (Tables E.2 & E.4)		View
56	Pressure relief device	A process upset causes an atmospheric tank to vent 27 kg of H2S to atmosphere via a low-pressure vacuum relief valve. The vent occurs immediately adjacent to an elevated platform on top of the tank. The site has an administrative procedure, including a swing gate, and a restricted access sign at the bottom of the tank. Dispersion modelling indicates there is no concern of harmful H2S concentrations at grade. This is a Tier 1 LOPC incident as the discharge quantity exceeds the Tier 1 threshold and the release is to a potentially unsafe location. No credit is taken for administrative controls when determining whether-or-not a release is to a potentially unsafe location. Tier 1 PSE (Tables E.2 & E.5) Same as above, except the barrier at the bottom of the stairs is controlled by a lock and key, thus preventing access to the platform. This is a Tier 3 KPI incident as none of the four consequences are applicable. In this example, the platform is not considered a potentially unsafe location as inadvertent access has been controlled by the use of a lock and key. This control is similar to car-sealing-open a block valve in the relief path of a PRD to ensure the relief path is not obstructed. Possible Tier 3 PSE KPI Same as above, except the dispersion modelling shows that there is the potential for H2S concentrations above acceptable levels at grade. This is a Tier 1 LOPC incident as the discharge quantity exceeds the Tier 1 threshold and the release is to a potentially unsafe location. In this case, the potentially unsafe location is grade and not the platform on the tank. Tier 1 PSE (Tables E.2 & E.5)		View
57	Pressure relief device	If a PRD activates/opens at 30 % of its set point due to a frozen pilot and the release is greater than the TRC for a Tier 1 event, is this a Tier 1 PSE event since the PRD failed to perform as designed? Not a Tier 1 or Tier 2 PSE The Tier 1 criteria for PRD releases is independent of whether the PRD opened at, above or below its set point or any other factors associated with design and installation. Releases from PRDs are only classified at Tier 1 or Tier 2 PSEs if one or more of the listed consequences occurs (i.e. rainout, discharge to a potentially unsafe location; an on-site shelter-in-place; public protective measures) and the release volume at the PRD discharge exceeds the Table 1 threshold quantity. None of those negative consequences is identified in the question; therefore, this event is not a Tier 1 PSE. Possible Tier 3 PSE KPI		View
58	Pressure relief device	An atmospheric relief device lifts and discharges greater than a Tier 1 threshold quantity of material. Dispersion modelling conducted as part of the relief device design indicates that a flammable mixture could impact an elevated work platform on an adjacent tower. Knowing that the platform could be impacted, the company controls access to the platform via their authorization system. At the time of the release, the wind was blowing in the direction of the elevated work platform, but no one is on the elevated platform. Is this a Tier 1 PSE?This is not a Tier 1 PSE. Although the relief volume exceeded the Tier 1 threshold quantity, the discharge did not result in one of the four defined consequences. One of those consequences is release to a potentially unsafe location. The definition of unsafe location specifically excludes ground level and elevated work structure locations that have a known potential for exposure of personnel to flammable mixtures, toxic substances, corrosive materials, or thermal radiation effects if that location is a controlled by virtue of authorized access or hard barriers with appropriate warning signs. Not a Tier 1 or Tier 2 PSE Alternate Scenario 1A worker was present on the platform in accordance with the site authorization requirements. The worker was able to escape unharmed. This is not a Tier 1 PSE. Even though a worker was present, by definition the work platform is not an unsafe location under the exclusion for controlled access. If the worker had been injured, then the event would be a Tier 1 or Tier 2 PSE dependent upon the severity of the injury. Not a Tier 1 or Tier 2 PSE Alternate Scenario 2The company did not control access to the platform via their authorization system or hard barriers and signage. This is a Tier 1 PSE, since the elevated work platform was impacted by the discharge and the exclusion for controlled access did not apply. The definition of unsafe location is independent of whether or not personnel are actually present at the time of the relief device discharge. Tier 1 PSE (Table E.3 & E.4.5 or 6) Alternate Scenario 3The company did not control access to the platform via their authorization system or hard barriers and signage. A worker was present on the elevated work platform at the time of the relief device discharge, but the wind direction was away from the platform. This is not a Tier 1 PSE. Since the work platform was not actually impacted at the time of release, it did not qualify as an unsafe location. The assessment of a LOPC for Tier 1 or Tier 2 categorization is based upon actual conditions and results at the time of release and not on alternate what-if conditions. Not a Tier 1 or Tier 2 PSE		View
59	Pressure relief device	A heat exchanger with natural gas on the tube side and water on the shell. There is a safety valve on the shell which is designed to protect the shell from over pressuring in the event of a tube rupture. The safety valve discharge is routed to the atmosphere via a high discharge point, such that dispersion modeling indicates that it is a “safe location”. A tube ruptures and the valve relieves. The natural gas is dispersed and none of following four consequences occur:1. Rainout2. Discharge to a potentially unsafe location3. An on-site shelter in place or on-site evacuation, excluding on-site shelter in place or site evacuation4. Public protective measures (e.g., road closure) including precautionary public protective measuresHowever, water is carried along with the natural gas and the water “rains out”. The water is cool/ambient and there is no risk of thermal burns to personnel. The material which “rains out” as a result of a relief system discharge is non-hazardous (water in this scenario). The release and subsequent rainout of the cool water would not be a classified as a PSE 1 or PSE 2 because there is no process safety issue related to this release since there is no Threshold Quantity for cool water.The 4 consequences for release from a pressure relief valve must be considered and consequences 2 through 4 clearly do not apply. Rainout is intended to apply to a material with the potential to cause harm which would not apply to cool water. If this logic were not applied then any release through a downstream destructive device or directly to the atmosphere containing any water, including water vapor, would eventually “rain out” the water making the exemption meaningless. If the water that was raining down was hot (>55 °C or 130 °F), then it would be considered rainout of a material with the potential to cause harm. Not a Tier 1 or Tier 2 PSE Possible Tier 3 PSE KPI		View
60	Pipelines and flowlines	A pipeline operated by the company leaks and releases 2,200 lbs/1000 kg of flammable gas above ground within one hour; however, the release occurred in a remote location and not on a facility. This is a reportable Tier 1 PSE since ‘remoteness’ is not a consideration and the release exceeded a Tier 1 threshold quantity. Tier 1 PSE (Tables E.2 & E.4)		View
61	Pipelines and flowlines	A pipeline leaks and releases 2,200 lbs/1000 kg of flammable gas above ground within 1 hour. A public road bisects the main facility and its marine docks. This pipeline originates in the facility and goes to the docks. The leak site happens to be off the site’s property in the short segment of piping that runs over the public road. Although the leak technically occurs off-site, this is a Tier 1 PSE since the facility owns and operates the entire segment of pipeline. Tier 1 PSE (Tables E.2 & E.4)		View
62	Pipelines and flowlines	A third-party truck loaded with a flammable liquid is traveling on Company premises and experiences a leak and subsequent fire and property damages of $125,000 (direct costs). The incident would not be a Tier 1 or Tier 2 PSE because truck incidents are excluded, except when they are connected to the process for the purposes of feedstock or product transfer. Not a Tier 1 or Tier 2 PSE Same as above except, the third-party truck is parked and being used for temporary onsite storage. This would be a Tier 1 PSE since the applicability exclusion does not include the use of trucks or railcars for onsite storage. Tier 1 PSE (Tables E.2 & E.4)		View
63	Pipelines and flowlines	There is a 200 bbl spill from a flowline containing light crude with a flash point <23 °C (73 °F). The spill ignites and results in damages to other equipment, a toxic gas release above the reporting threshold, along with three LWDC injuries and one fatality. This is a Tier 1 PSE. The site would record a single PSE with multiple consequences (e.g., one fatality, three day away from work injuries, fire, and threshold quantity of liquid with a flash point <23 °C (73 °F) and toxic gas). Tier 1 PSE (Tables E.1 & E.2 & E.4 & E.5)		View
64	Pipelines and flowlines	An underground pipeline operated by the facility leaks and releases 1,000 bbl of heavy crude oil with flash point > 60 °C (140 °F) and ≤ 93 °C (200 °F) at a temperature below its flash point within the facility over a period of three days (13.9 bbl/hr). The spill results in contaminated soil that is subsequently remediated. This is a Tier 2 PSE since the leak rate was greater than the Tier 2 threshold quantity; note that there is no Tier 1 threshold quantity for this material. Tier 2 (Tables E.2 & E.4)		View
65	Pipelines and flowlines	A pipeline that is owned, operated and maintained by Company A crosses through Company B’s property. The pipeline has a 1500 lbs release within an hour from primary containment of flammable gas and causes a fire resulting in greater than $100,000 damage to Company A’s equipment. This is not a PSE for Company B since the pipeline is not owned, operated or maintained by Company B. This would be a Tier 1 PSE incident for Company A. Tier 1 PSE (Tables .1, E.2 & E.4)		View
66	Pipelines and flowlines	Failure of a subsea pipeline during leak testing results in a rapid methanol release of 550 kg into the sea. The subsea line is part of the process and the release is unplanned and uncontrolled. The release quantity exceeds the Tier 2 threshold for outdoor release of flammable liquids with boiling point >35 °C and flash point <23 °C. Although in this case there was no potential for the release to ignite, determination of a PSE is not dependent on the environment into which the LOPC occurs. Tier 2 (Tables E.2 & E.4)		View
67	Marine and land transport	A Company-operated Marine Transport Vessel that had just disconnected from an offshore rig has an onboard spill of 14 bbl Of drilling fluids with a flash point > 93 °C (200 °F) released at a temperature below its flash point. The event is not a PSE because Marine Transport Vessel incidents are specifically excluded, except when the vessel is connected to the process for the purposes of feedstock or product transfer. This is likely to be a reportable spill to the environment within other KPIs of the Company. Not a Tier 1 or Tier 2 PSE If the marine transport vessel were still connected to the rig when the spill occurred, it would be a possible Tier 3 KPI since the flash point of this drilling mud is higher than upper limit (93 °C) and it is released at a temperature below its flash point (Table E.4). Possible Tier 3 PSE KPI (Tables E.2 & E.4)		View
68	Marine and land transport	A third-party barge is being pushed by a tug and hits the Company dock. A barge compartment is breached and releases 50 bbl of diesel to the water. This LOPC event is not a PSE since the barge was not connected to the process for the purpose of feedstock or product transfer. Not a Tier 1 or Tier 2 PSE		View
69	Marine and land transport	A marine survey boat is pulling a tube screen for seismic survey and a shark bites into the tube releasing 7 bbl of hydraulic fluid into the water. This LOPC event may be a reportable spill to the environment but not a PSE because exploration activities are not within scope for PSE KPIs. Not a Tier 1 or Tier 2 PSE		View
70	Marine and land transport	A Company railcar derails and spills more than 7 bbl of gasoline while in transit. The LOPC event is not a PSE since it is not connected to the process for the purpose of feedstock or product transfer, but this is likely to be a reportable spill to the environment within other KPIs of the Company. Not a Tier 1 or Tier 2 PSE		View
71	Marine and land transport	A third-party truck/trailer on Company premises connected to the process has a spill of condensate greater than 7 bbl in less than an hour while loading. The event is a Tier 1 PSE since the truck is considered part of the process while it is connected or in the process of connecting/disconnecting from the process for the purpose of feedstock or product transfer. Tier 1 PSE (Tables E.2 & E.4)		View
72	Marine and land transport	A truck enters a well pad, parks and is connected to the crude tank load line. After loading the product, the truck disconnects and leaves the well pad and an accident occurs leading to a LOPC on the well pad lease road. Is this a PSE?This would not be a PSE per API 754; the truck was not connected nor in the process of disconnecting from the process; therefore, the subsequent LOPC should be counted as a transportation event. Even though it is not a PSE per API 754, it should be investigated and corrective action taken to prevent a recurrence. Not a Tier 1 or Tier 2 PSE Alternate ScenarioA truck enters the well pad and parks with other trucks waiting to be loaded. The truck contains several hundred gallons of product from the previous load. The truck develops a leak resulting in a LOPC of product in excess of the Tier 1 threshold quantity. Is this a Tier 1 PSE?This is not a Tier 1 PSE since the truck was not connected to the process nor in the process of connecting/disconnecting from the process. Similarly, the truck would not qualify as ‘active staging’ since by definition active staging only applies to truck/rail waiting to be unloaded. Therefore, the LOPC should be counted as a transportation event. Not a Tier 1 or Tier 2 PSE		View
73	Destructive devices	The flare system is not functioning properly due to inactive pilots on the flare tip. During this time, flammable gas is sent to the flare due to overpressure in a process unit. The volume of the unlit vapour released to the atmosphere through the flare is greater than the Tier 1 threshold. The flare is not designed for cold venting. This would be classified as a Tier 1 PSE since the downstream destructive device which was not designed for cold venting did not function correctly and an unplanned/uncontrolled discharge (LOPC) exceeded a threshold release quantity. Tier 1 PSE (Tables E.3 & E.4)		View
74	Destructive devices	100 bbl of crude oil are inadvertently routed to the flare system through a PRD. The flare knockout drum contains most of the release; however, there is minimal liquid phase hydrocarbon rainout. This is a Tier 1 PSE since the volume released from the PRD to a downstream destructive device exceeds the threshold quantity in Table E.4 and resulted in one of the four listed consequences (i.e., rainout). Tier 1 PSE (Tables E.3 & E.4)		View
75	Destructive devices	A PRD release of sour gas less than Tier 1 but more than a Tier 2 threshold quantity is routed to a flare which exposes two personnel to toxic SO2/SO3 vapours resulting in a lost work day case (LWDC) incident. This is a Tier 1 PSE since the PRD discharge resulted in a days-away-from-work injury. Tier 1 PSE and a LWDC (Table E.1) Same as above, except the toxic material was observed or detected, without injury, at an unrestricted elevated work structure. This is a Tier 2 PSE since the release quantity from a PRD to a downstream destructive device exceeds a Tier 2 threshold quantity and results in an unsafe release (discharge to a potentially unsafe location) as specified in the list of Tier 2 consequences. If the elevated platform was restricted, then this is not a Tier 1 or Tier 2 PSE and a company may choose to include this event in their Tier 3 indicators. Tier 2 PSE (Tables E.3 & E.5)		View
76	Destructive devices	A propane tank releases through a PRD to the flare system. The pilots on the flare system are not working properly, and the flare does not combust the vapours. The event occurs over a period of 45 minutes. The volume of propane release was estimated to be 1300 pounds (ca. 600 kg) and the release generated an explosive atmosphere above grade without being ignited. The amount of PRD discharge and resultant unintended propane release from the flare exceeded the Tier 1 threshold quantity. This is a Tier 1 PSE since the flare did not function correctly and a LOPC resulted in one of the four consequences (discharge to a potentially unsafe location) with a release amount above Tier 1 thresholds. Tier 1 PSE (Tables E.3 & E.4) If the flare was designed for cold venting and the LOPC resulted in none of the four consequences, a Company using a Tier 3 KPI to track demands on safety systems would report this event as an activation of a PRD resulting in a release to atmosphere via a downstream destructive device. Possible Tier 3 PSE KPI		View
77	Destructive devices	An upset causes a PRD to open and release fuel gas to the facility flare system. The flare system works properly and combusts the vapour release which came from the PRD. This is not a Tier 1 or Tier 2 PSE because the PRD release was routed to a downstream destructive device that functioned as intended (i.e., did not cause one of the four listed consequences).A company may record this as a Tier 3 challenge to the safety system. Possible Tier 3 PSE KPI Alternate Scenario:An upset causes a PRD to open and release a two-phase mixture exceeding a Tier 1 or 2 threshold quantity. The liquid is carried over to the flare drum knockout, but no release to atmosphere in the form of rainout occurs. Is this a Tier 1 or Tier 2 PSE?This is not a Tier 1 or Tier 2 PSE since the PRD release was routed to a downstream destructive device that functioned as intended (i.e., did not cause one of the four listed consequences).A company may record this as a Tier 3 challenge to the safety system. Possible Tier 3 PSE KPI		View
78	PSE Reporting Responsible Party	The facility experienced a Tier 1 PSE. The facility is owned by Company A, but is operated by Company B. Who is the responsible party, who should count the PSE?The answer depends on the nature of the contract between the two parties. As the contract operator, does Company B also have responsibility for the performance of the facility (i.e. In this case would they be expected to perform the investigation and identify and implement corrective action?). If ‘yes’, Company B is the responsible party and they would record the PSE. If ‘no’ and Company B is simply acting upon the instructions of Company A, then the Company A is the responsible party and they would record the PSE. Tier 1 PSE		View
79	Destructive devices	There is hydrocarbon rainout on a flare when a compressor is started. Investigation finds that natural gas condensate had collected in a low point in the flare line over many days and had been ‘blown’ to the flare when the compressor started and caused the rainout. The calculated volume of condensate in the low point is 1.5 bbl.This is an upset emission from a permitted or regulated source.Although discharge to flare during compressor start-up would not normally be consider an LOPC, given that the activity/release is considered unplanned/uncontrolled and the downstream destructive device malfunctioned (or otherwise failed to destroy the liquid), resulting in liquid rainout, the event would be considered a PSE of Tier based on the total quantity of hydrocarbons released into the relief system (i.e. not just the quantity of hydrocarbon liquids released as the ‘rainout’).Since the released amount is more than Tier 2 threshold for condensate (1 bbl), the incident would be classified as a Tier 2 PSE Tier 2 PSE (Tables E.3 & E.4)		View
80	Destructive devices	The flare system is not functioning properly due to inactive pilots on the flare tip. During this time, flammable gas is sent to the flare due to an overpressure in a process unit. The volume of the flammable gas through the PRD is greater than the Tier 1 threshold and it results in the formation of a flammable mixture at grade. This would be classified as a Tier 1 PSE since the PRD discharge is greater than the Tier 1 threshold quantity and resulted in a discharge to a potentially unsafe location. Tier 1 PSE (Tables E.3 & E.4) Same as above except, the flare is designed for cold venting which results in the flammable gas being dispersed into the atmosphere without creating any one of the four listed consequences. This is not a Tier 1 or Tier 2 PSE. A company may count this as a Tier 3 PSE KPI. Possible Tier 3 PSE KPI		View
81	Vacuum truck operations	After collecting a load from an adjacent unit, a vacuum truck is parked at the wastewater treatment facility awaiting operator approval to connect to the process and discharge its load. While waiting the vacuum truck malfunctions and vents process material to the atmosphere. This is not a PSE since vacuum truck operations are excluded unless loading, discharging or using the truck’s transfer pump. Not a Tier 1 or Tier 2 PSE		View
82	Vacuum truck operations	A vacuum truck outfitted with a carbon canister on the vent is loading a spill of hydrocarbons. The carbon canister catches fire which escalates to the point of creating more than $10,000 in damage to the vacuum truck. This is a Tier 2 PSE because the original spill of hydrocarbons constitutes the LOPC and the response to the LOPC results in one of the Tier 2 consequences. Tier 2 PSE (Table E.1) Same as above, except the vacuum truck is connected to the process. This is a Tier 2 PSE since the direct costs from the fire damage exceeded $2,500. The excess of hydrocarbon vapours absorbed by the carbon canister is the uncontrolled LOPC. Tier 2 PSE (Table E.1)		View
83	Vacuum truck operations	A vacuum truck was being used to remove sludge and crude oil from a separator that is inside a building to allow for mechanical inspection. The vacuum truck driver accidentally reversed the flow of the vacuum truck’s transfer pump and caused crude oil to flow back into the separator and 1 bbl of crude flowed out of the separator through the manway which had been removed onto the building’s floor.As described, the vacuum truck would be considered part of the process since the vacuum truck transfer pump was being used. This event would be classified as a Tier 2 PSE since there was an LOPC out of the manway that exceeded the indoor release threshold quantity for this type of crude. Tier 2 PSE (Tables E.2 & E.4)		View
84	Evacuation or shelter-in-place	A small quantity (less than Tier 2 threshold quantity amount) of very odorous material (e.g. methyl mercaptan for odorizing natural gas) inadvertently enters a cooling water system via an exchanger tube leak. The material is dispersed into the atmosphere at the cooling tower. An elementary school teacher decides not to conduct recess outside due to a noticeable odor even though officials deemed no shelter-in-place was necessary. Is this a Tier 1 or Tier 2 PSE? This is not a Tier 1 or Tier 2 PSE. The school teacher acting from an abundance of caution and deciding not to conduct recess outside does not constitute an officially declared shelter-in-place or evacuation.The facility may choose to capture this event as a Tier 3 other LOPC. Possible Tier 3 PSE KPI		View
85	Evacuation or shelter-in-place	A pressure relief device (PRD) discharges to a scrubber that vents to atmosphere. The scrubber is overwhelmed by a flow rate greater than its design resulting in a discharge that is detected by fenceline monitoring and a public shelter-in-place order is issued. The PRD release quantity is estimated to be less than the Tier 1 thresholds. This is a PSE with a Tier 1 consequence regardless of the quantity released exceeding a threshold quantity because of the officially declared community shelter in-place Tier 1 PSE (Table E.1)		View
86	Evacuation or shelter-in-place	A pressure relief device (PRD) activates on an offshore platform, resulting in a substantial release exceeding Tier 1 thresholds, causing precautionary partial evacuation or platform abandonment (some or the entire workforce). This is equivalent to an onshore situation resulting in an ‘onsite shelter in place’ and would be a Tier 1 PSE.Mustering offshore to a safe location on the platform is not considered a sufficient consequence to trigger reporting a Tier 1 or 2 PSE.The partial evacuation of an onshore gas plant to a safe muster point, onsite or offsite, is also considered a ‘shelter-in-place’ consequence, which would result in a Tier 1 or Tier 2 PSE following LOPC which meets or exceeds the threshold quantities in Table E.4. Tier 1 PSE (Tables E.3 & E.4)		View
87	Evacuation or shelter-in-place	Less than 1 pound (0.45 kg) of H2S gas is released while loading a molten sulfur car. The release is detected by a local analyser and triggers a unit response alarm. An off-duty police officer living in a nearby home advises his neighbors to evacuate because “an alarm like that means there’s a problem at the plant.” This is not an officially declared evacuation or shelter-in-place because in this situation the officer is acting as a private citizen suggesting a precautionary measure; therefore, this is not a Tier 1 or Tier 2 PSE. The site may choose to capture this event as a Tier 3 PSE KPI . Possible Tier 3 PSE KPI		View
88	PSE Reporting Responsible Party	Regarding LOPC events associated with marine transport, truck and rail operations: A company has 1) met the requirement of “connected to the process for the purposes of feedstock or product transfer,” and 2) exceeded either a Tier 1 or Tier 2 threshold quantity. When classifying the event, is ownership or operation of the transport additional criteria? If the transport (vessel, barge, truck, or rail car) was owned or operated by a third-party, would it still be a PSE?The ownership of the transport equipment involved in marine transport, truck and rail operations has no bearing on what constitutes a PSE, nor does the involvement of contract workers. Where a facility is a joint venture operated by others, the PSE is reported by the responsible party. Tier 1 or Tier 2 PSE		View
89	PSE Reporting Responsible Party	A 3rd party tank truck operator begins filling his tanker at an unstaffed loading rack. The belly valve of the tanker truck was left open and when the operator disconnected the loading hose, a Tier 1 quantity of flammable liquid was spilled. Is this a Tier 1 PSE?This is a Tier 1 PSE since the LOPC occurred while disconnecting from the process (i.e., the loading rack). Although the 3rd party tank truck operator has an obligation to follow the operating procedures (i.e. close the belly valve before disconnecting the loading hose), he is not the operator of the facility and therefore he is not the responsible party.The Company that owns or operates the loading rack is the responsible party. The Company establishes the operating procedures, installs prevention measures, authorizes 3rd parties to use the facility, etc Tier 1 PSE		View
90	PSE Reporting Responsible Party	A contractor performing work overpressured the contractor supplied tank which is connected to a process. The tank roof blew off and traveled 45 ft where it landed on the cab of the contractor’s CO2 supply truck causing $15,000 in damage. Since this was a turn-key job by the contractor, the Company had no contractual liability for the event or the damage. Is this a PSE?Although the contractor is performing a turn-key job on behalf of the Company, the Company is still the responsible party (i.e. the party responsible for delivering safe, compliant and reliable operations) and the Company should record this event as a Tier 2 PSE. Tier 2 PSE		View
91	PSE Reporting Responsible Party	The custody transfer meter for a refined products pipeline that is owned, operated, and maintained by a pipeline company is physically located inside the fence line of a refinery. On a quarterly basis, the pipeline company checks and calibrates the meter. During the proving operation, a lineup error results in a Tier 1 threshold quantity release of a flammable liquid. Is this a Tier 1 PSE for the pipeline company or the refinery?This is a Tier 1 PSE for the pipeline company. Even though the LOPC occurred inside the fence line of the refinery, the Tier 1 PSE is recorded by the pipeline company since they own, operate, and maintain the custody transfer meter and the portable meter proving station. The pipeline company is the responsible party. Tier 1 PSE		View
92	PSE Reporting Responsible Party	Company A owns a pipeline that has been out of service for 2 years. The pipeline runs from Company A’s facility to a marine terminal owned by the government. Company A is in the process of cleaning up and decommissioning the line for removal via a pigging operation. During the course of this operation, 23 bbls of a Threshold Release Category 8 material (60°C < FP < 93 °C, released < FP) is released in an hour due to a failure of a piping component. The failure does not occur on Company A’s property but on the government’s property. The entire release is contained in a concrete bunker on the government’s property. Since this line has been out of service for a number of years, is no longer connected to the process, and the spill did not occur on Company A’s property, is this a PSE?This is a Tier 2 PSE for Company A. There was an unplanned or uncontrolled release of TRC-8 material from a process that exceeded the Table E.4 threshold quantity in a 1-hour period. Even though the line was out of service and had been for several years and was no longer connected to the process it is still process equipment. Also, Company A is the responsible party; it doesn’t matter that the release occurred on government property. Tier 2 PSE		View
93	PSE Reporting Responsible Party	Two pipeline companies share a common right of way. The pipelines are independently owned and operated. Company A’s pipeline experiences a LOPC leading to a Tier 1 fire and explosion that subsequently causes Company B’s pipeline to also have a Tier 1 LOPC. Is this one or two Tier 1 PSEs, and who reports the PSEs?In this case, there are two responsible parties. Each pipeline company is the responsible party for their own line. Each pipeline company experienced a LOPC that resulted in a Tier 1 consequence. Each company would report a Tier 1 PSE. The fact that Company A’s LOPC and fire was the initiating cause for Company B’s LOPC does not make the Company B LOPC a continuation of the first event. Tier 1 PSE In the case that both pipelines were owned by the same company and the two LOPCs impact the same population or equipment, there is only one responsible party and only one Tier 1 process safety event is recorded. Tier 1 PSE		View
94	Well Operations	A drilling subsurface blowout comes to surface (along the casing or along another path to the surface) resulting in a gas release of over 45 tonnes of flammable gas to atmosphere over a period of 72 hrs. This LOPC is a PSE and would be classified as Tier 1 because the average leak rate over the period of 1 hour exceeds the threshold quantities. Tier 1 PSE (Tables E.3 & E.4)		View
95	Well Operations	During an extended well test at 10,000 Barrel Per Day rate with 1250 gas-to-oil ratio, a slug of liquid extinguished the flare flame, resulting in a release of uncombusted natural gas at 520,000 SCF per hour until the flare was reignited 10 minutes later.This is a Tier 1 PSE because the flare failed to operate as designed (it was not designed for cold venting) when it flamed out resulting in an unplanned and uncontrolled release (LOPC) of flammable gas significantly exceeding the Tier 1 release quantity of 1100 lbs (500 kg) within one hour. Tier 1 PSE (Tables E.2 & E.4)		View
96	Well Operations	While drilling a well, there is a loss of hydrostatic overbalance resulting in a kick. Standard well control procedures are followed to reestablish full control, resulting in the planned and controlled venting of the gas kick through the mud gas separator (MGS) vent. This was a planned release consistent with procedures and therefore not a Tier 1 or Tier 2 PSE, even though the gas release may have exceeded the release quantity thresholds for the PSE KPI. Companies may report this within their Tier 3 KPIs because this is a demand on a safety system. Possible Tier 3 PSE KPI Same as above, except the rig is a Mobile Offshore Drilling Unit with an enclosed shaker house. While routing through the MGS, the liquid leg is lost sending hydrocarbons to the shaker room. The gas released to the shaker room is calculated to be 34 kg. This release was unplanned and uncontrolled so categorized as a PSE. The volume is above 25 kg, the Indoor Tier 2 threshold for methane, so this release would be categorized as a Tier 2. Tier 2 PSE (Tables E.2 & E.4)		View
97	Well Operations	While drilling a well, a shallow gas pocket is struck, causing a loss of well control. Mud, cuttings and 100 barrels of oil are released to the environment, and 1.8 MMSCF of gas (about 64,000 kg) are discharged through the diverter valve to the atmosphere. The release continued for two days at an average of 900,000 SCFD. This meets the criteria for a Tier 1 PSE because of the flammable gas LOPC. It is also a reportable spill (over 1 barrel) to the environment under company’s environmental reporting requirements. Tier 1 PSE (Tables E.2 & E.4) and a reportable oil spill to the environment.		View
98	Well Operations	100 kg (220 lbs) of diesel fuel spills within an enclosed area during a period of 30 minutes while transferring fuel to a drilling platform while running casing in-hole. A LOPC, while connected to a platform when well operations are being conducted, is reported as a process safety event. This would be a Tier 2 PSE because the fuel system on a platform is considered part of the process, and the spill exceeds the 50 kg indoor threshold quantity for Tier 2 for flammable liquids. If the spill occurred during transfer of fuel to a MODU (e.g., jack-up or drill ship) contracted to carry out drilling operations at a company well site, this would also be included as a PSE, as above. However, if the spill occurred when the MODU under contract was moving between well sites then no well related operations are taking place and would not be considered ‘connected to the process’ and would not be a PSE. Tier 2 PSE (Tables E.2 & E.4)		View
99	Well Operations	During the completion with the drilling rig, the derrick man was asked to mix a KCl brine pill in the slug pit. The derrick man forgot to close the transfer valve, the slug pit quickly overflowed and approximately 10 bbls of 7% KCl of brine with 112 kg of KCl (261 lbs) was lost to the ground. The pits are considered part of the process during well operations and the release was unplanned. KCL brine is not classified as a hazardous solution and does not fall within the material hazard classifications (e.g. toxicity, flammability, corrosivity) associated with an upper threshold release quantity. This incident would be classified as a PSE Tier 3 Release. Possible Tier 3 PSE KPI As above except 10 bbls of Diesel-based Oil Based Mud overflows. If the diesel-based drilling mud has a flash point below 93 °C and so 10 bbls is over the Tier 2 threshold. It is important to verify the flash point and the release temperature of the mud. PSE Tier 2 (Table E.4)		View
100	Well Operations	During drilling operations, 1.5 bbl of diesel with flash point less than 60°C (140°F) are released from a fuel tank indoor in a period of 90 minutes. The diesel was contained in the secondary containment and there was no fire. The LOPC occurred while Well Operation were being conducted and since the released amount in one hour is about 1 bbl. and more than Tier 2 indoor threshold (0.7 bbl), the event is a Tier 2 PSE. Tier 2 PSE (Tables E.2 & E.4) Same as above but the release is outdoor, it is not a Tier 2 PSE since the released amount is less than the outdoor threshold (1.4 bbl); possible Tier 3 PSE KPI. Possible Tier 3 PSE KPI		View
101	Well Operations	During a deep-water offshore drilling operation, a leak of oil-based mud (OBM) is noted from the slip joint at the top of the marine riser. The flash point of the OBM is less than 93 °C and the total volume released to the sea is estimated as 8 bbls over a 1-hour period. The riser system is part of the process. As the OBM flash point is between 60 °C and 93 °C and it was released at a temperature lower than its flash point, it is classified as a Tier 2 event. Tier 2 PSE (Tables E.2 & E.4) As above, but the 8bbls were released over a 4-hour period. In this case, the maximum release rate was less than the 7bbl/hr threshold, so this is not a Tier 2 event but is a possible Tier 3 KPI based on the company’s reporting criteria. Possible Tier 3 PSE KPI		View
102	Well Operations	During normal drilling operations, as part of routine maintenance, rig personnel changed a generator’s (Generator A) oil filter and restarted it. Shortly after restarting generator A, a second generator (Generator B) caught fire. It was determined that generator A’s oil had leaked from the oil filter and sprayed onto generator B, causing the fire. Cost to repair the fire damage was $25,000. The rig was conducting well operations, so the generator is part of the process. The Operator is responsible for reporting this PSE, not the Drilling contractor, as the Operator is the responsible party. Tier 2 PSE (Table E.1)		View
103	Well Operations	While executing a workover, performing a remedial cement squeeze with a pulling unit, the cement unit was being refueled. While refueling the fuel tank overflowed and 3 bbls of diesel was discharged to the ground. well operations were being conducted and since the cement unit is connected to the well, it is considered part of the process. Therefore, this is a PSE; the volume is ≥1.4 bbls making this a Tier 2 PSE.As above, but with secondary containment installed below the fuel tank so the spill did not reach the ground/environment. In this case the spill is still considered a PSE as it was an unplanned loss of primary containment (LOPC). Tier 2 PSE (Table E.4)		View
104	Well Operations	While performing a wireline perforation job on a horizontal well on land, pumps were used to pump down the wireline tools. The wireline BOP and lubricator were supported by a crane. The lubricator disconnected from the wellhead crown valve when the quick-connect malfunctioned and 160 bbls of brackish water was discharged to the ground. The well was isolated by the wireline operator closing a remotely operated shear seal valve integral to the X-tree. As the lubricator is connected to the well it is part of the process. As brackish water is non-hazardous, there is no Tier 2 or 1 threshold exceeded, a company may count this as a Tier 3 KPI. Possible Tier 3 PSE KPI Same as above but the fluid used was a gel containing 8 bbls of strong bases. The material released exceeds the Tier 2 threshold for strong Acids or Bases (> 7 bbls), so this is a Tier 2 PSE. Tier 2 PSE (Table E.6) Note that a LOPC of strong acids or bases cannot be Tier 1 PSE based upon quantity released, no matter the volume.If the fluid used was a gel containing moderate bases (alkali), this would be also a possible Tier 3 event. It is not a Tier 1 or 2 PSE as the moderate acids or bases are classified as non-hazardous and does not have threshold volumes. Possible Tier 3 PSE KPI		View
105	Well Operations	While performing a frac-pack stimulation treatment offshore the treating pressure started to increase quickly due to a potential screen out, the engineered pressure relief valve (PRV) activated as designed and discharged 44 bbls of frac fluid to a catchment tank on the frac vessel. The frac tanks and associated pipework is connected to the well and hence considered to be part of the process. The fluid was KCL brine with additives used for friction reducer, the volume was estimated at 20 bbls of brine and polymer. the activation of the relief valve is considered a demand on a safety system so this is a process safety event. However, as the fluid was contained within the tank, this would not be a Tier 1 or Tier 2 PSE. The discharge was to a safe location as designed without any consequences listed in Table E.3, i.e. the volumes do not matter. A company using a Tier 3 PSE KPI to track demands on safety systems could report this event as an activation of a PRD.If the fluid overflowed the catchment tank on the frac vessel, this would also be a possible Tier 3 PSE. It is not a Tier 1 or 2 PSE as the fluid is not hazardous and does not have threshold volumes. Possible Tier 3 PSE KPI (Table E.3)		View
106	Well Operations	A Hydraulic Work-Over unit was involved in abandonment operations of a live well, the work string was being snubbed into the well. Just after a joint of pipe was made up and lowered into the well, flow was observed coming from the top of the pipe indicating that the back-pressure valves in the string had failed. The pipe was lowered to the work basket level and a fully opening safety valve was stabbed and closed to stem the flow. It was subsequently determined that 65 kg (143 lbs) of methane gas was released. This is a Tier 2 PSE because there was a LOPC of 50 kg (110 lbs) or more of flammable gas in any one-hour period. Tier 2 PSE (Tables E.2 & E.4)		View
107	Well Operations	A Coiled Tubing Unit was involved in a tubing clean-out activity pumping acid. During the process of pumping a strong acid downhole, fluid was observed to be spraying from between the wraps of coil left on the drum. Pumping was halted and the leak stopped indicating the downhole check valves were fully functional. calculations established that 0.8 bbl (115 kg/253 lbs) was released. No further fluid was seen leaking from the coil and preparations were made to pull out of hole. This is not a Tier 1 or Tier 2 PSE since the spill event did not exceed the threshold quantity of ≥1000 kg (2200 lbs) of strong acid in any one-hour period. However, this event can be reported within the Tier 3 KPIs of the company or facility. Possible Tier 3 PSE KPI Same as above, except the Coiled Tubing operator was sprayed in the face with acid when he went to investigate the leak. If this incident had resulted in a recordable injury which was not a LWDC or fatality (i.e., a restricted workday case or a medical treatment case), it would be a Tier 2 PSE. Tier 2 PSE (Table E.1) and a recordable injury		View
108	Well Operations	A well test was being conducted on an onshore exploration well, flowing to a burner pit via a test separator package. A leak occurred in the pipework connecting the Pressure Relief Device to the separator vessel. The process operator initiated an Emergency Shutdown (ESD), and the well was successfully closed-in. The liquids in the test package were blown-down to the burner pit at a safe distance from the test package. Based on the vessel pressure and the hole size a process calculation determined that 21 kg (46 lbs) methane was released to atmosphere. The well test package is connected to the well and considered to be part of the process. This is not a Tier 1 or Tier 2 PSE since the spill event did not exceed the threshold quantity in any one-hour period. However, this event can be reported within the Tier 3 KPIs of the company or facility. Possible Tier 3 PSE KPI Same as above, except the gas released ignited and the fire from a leak causes damage greater than $15,000 but does not create a LOPC greater than the threshold quantity or cause a fatality or serious injury.This is a Tier 2 PSE since the damage was greater than $2,500. Tier 2 PSE (Table E.1)		View
109	Well Operations	During a rig-supported electric line perforating operation during the completion of a production well, a methane gas release is experienced from the quick disconnect in the lubricator. The rig is winterized, and the drill floor is fully enclosed. Following an initial delay to stem the release, the wireline BOP was closed around the wireline and after 15 minutes the leak has ceased. During this time a total of 30 kg (66 lbs) of methane has been released above the drill floor. The LOPC occurred while the lubricator was connected to the well and the release amount exceeds the ‘indoor’ threshold for a Tier 2 PSE (25 kg or 55 lbs) and since the released amount occurred in less than one hour, the event is a Tier 2 PSE. Tier 2 PSE (Table E.4) A similar leak during a stand-alone wireline operation (outdoor) would not be recognized as a Tier PSE as the applicable threshold for a Tier 2 PSE would be >50 kg or 66 lbs, however the WCI classification will still apply. Possible Tier 3 PSE KPI. Possible Tier 3 PSE KPI		View
110	Well Operations	During a deep-water offshore intervention operation, a subsea leak is found by the ROV from an Intervention Riser System deployed from a light well intervention vessel performing wireline operations on a producing well. An estimated 4 bbls of condensate were released into the sea before the tree valves were closed (duration < 1 hr). The riser system is part of the process, and the release quantity and fluid type exceed the Tier 1 threshold for outdoor release of flammable liquids. The determination of a PSE is not dependent on the environment into which the LOPC occurs (e.g. to ground or in the water column). Tier 1 (Tables E.2 & E.4)		View
111	Well Operations	A wellhead maintenance contractor started to remove the vent cap from a grease injection fitting on an annulus valve. The well had sustained casing pressure in that annulus. He used one wrench rather than two and so unscrewed the entire fitting. The corroded fitting ejected causing a continuous release of gas to the atmosphere in the open wellbay until the annulus gate valve was manually closed. An estimated 75 kg of gas was released. The wellhead is part of the process, and the release was unplanned and uncontrolled. The release quantity exceeds the Tier 1 threshold for outdoor release of flammable gases. Tier 1 PSE (Table E.2 and E.4) As above with a release volume less than the Tier 2 threshold, but the technician is hit and injured by the ejected fitting and results in a Lost Workday Case. In this case, although the volume does not exceed the release threshold, the injury associated with the release classifies this as a Tier 1. Tier 1 PSE (Table E.1) and a LWDC		View
112	Well Operations	During a wireline activity running in hole with the tool string on slick line, a minor release of gas is observed from the stuffing box. The hydraulic pressure on the stuffing box is slightly increased within the operating envelope of the control equipment and the leak ceases, so operations continue. Minor releases from the stuffing box are inherent with the process and controlled procedurally. This event is therefore not considered an LOPC if the release is timely addressed and managed by adjusting the stuffing box in accordance with the operating procedures for the equipment. Not a Tier 1 or Tier 2 PSE As above, but now it is not possible to stem the release by manipulation of the hydraulic pressure within the operating limits as the stuffing box elements have worn down and will not provide an adequate seal anymore. The wireline BOP is closed, and the packing element was replaced before continuing operations. Now the release of 15 kg of methane is considered a LOPC as the equipment has failed to maintain the containment. As the released volume was below the threshold for an outdoor methane release, it is not a Tier 2 PSE but a possible Tier 3 KPI. Possible Tier 3 PSE KPI		View