Safety Incident Topic : Thermal Burns To Operator
Location Of Incident : Toledo Refinery, United States
Date Of Incident : 25 May, 2006
Brief Account Of Incident
A Vacuum Truck Operator at Toledo Refinery received significant second degree burns while preparing to offload hot water to a sump. The employee was transported by Life Flight to a hospital for treatment.The investigation team was not able to interview the injured employee. OSHA opened a formal investigation related to the incident that remains on-going at the time of this report.
Investigation
Onyx Industrial Services provides routine vacuum truck and pressure washing services to the refinery. The vacuum tank is fitted with an intake (vacuum valve) and discharge valve. Valves are four-inch, 1/4 turn ball valves with four inch camlock tailpieces. The operator was using a three inch hose for vacuuming (filling the tank) and another three-inch hose at the discharge sump. The intake valve on this truck fitted with a four-to-three inch reducer on the tail-piece to allow connection of a three-inch hose with camlock coupling.
After the incident, BP and Onyx inspected the vacuum truck. The vacuum truck was approximately ¾ full and the discharge valve was not leaking. The first person to arrive on-scene after the incident observed the discharge valve wide open, and a four-inch dust cap on the ground. The vacuum valve was closed, with the reducer, and dust cap installed. Manufacturer literature advises dust caps are not intended to contain hazardous materials or pressure.The injured had completed a Job Safety Analysis the day of the incident. He was wearing fire retardant clothing, safety glasses, hard hat, work boots and gloves.
What Went Wrong (Critical factors)
The injured either failed to notice the discharge valve was open during inspection, or opened the discharge valve before removing the four inch dust cap. The employee was positioned immediately behind the truck. As he removed the four-inch dust cap, he was exposed to the released contents of the vacuum truck.
Critical factors:
CF1: the technician removed cap from the discharge tailpiece of the vacuum truck while the discharge valve was in an open position
CF2: an inadequately protected technician burned from contact with hot water (estimated at 150 degrees or greater)
Possible Immediate Causes
- Unintentional error, improperly prepared equipment·
- Inadequate protective equipmentPossible System Causes·
- Inappropriate course of action (steps to offload truck)· Identification of worksite hazard (hot fluid, dust cap use, PPE)·
- Identifation of critical safe behaviours·
- Method of verifying absence of hot water behind cap
Key Learnings (addressed by actions)
1· Do you positively verify absence of thermal hazards before removing caps, plugs or valves from fixed andmobile equipment?
2· What safeguards are in place to manage fluids at temperatures >120degree F? (second degree burns occurwith exposure to hot fluids in five seconds at 140 degress F and one second at temperatures of 158 degrees F)
3· Is your equipment and that of your contactors designed to minimize the consequences of human error?
4· What PPE is required when transferring hot fluids?
5· How do you verify that contractors are conforming to their written HSE Plans (e.g equipment inspection, training, procedures, assesment)?
24 June 2006
16 June 2006
Electrical Flash Over
Safety Incident Topic : Electrical Flash Over
Location Of Incident : Kuantan, Malaysia
Date Of Incident : 24th July, 2005
Brief Account Of Incident
A lost time injury incident occurred when a contractor worker was exposed to a severe electrical flash-over while servicing the 11KV cable connection bar in a substation during a turnaround.
Outcome
First degree burn due to severe electrical flash-over.
Active Failures
The Active Failure leading to the incident was the 11KV cable connection bar was still energized when the contractor worker applied the earth bonding clamps resulting in a severe electrical flash-over.
Lessons Learned
1. Two separate PTWs were issued for the same activity:
i) servicing of front and back portion of switchboard and
ii) switching for isolation of front portion of the switchboard. A single PTW shall be issued for one activity and the switching for isolation shall be recorded in the Electrical Isolation Certificate.
2. The following shortcomings were observed in permitting processi) PTW – electrical hazard not identified, inadequate precautions & electrical PPEs not specified and contractorworker did not signed andii) Electrical Isolation Certificate – Lock-out and tag-out section not filled, Competent Person signing is not qualifiedBO and inadequate briefing/communication between issuer and receiver. The established PTW procedure shall bestrictly enforced and audited regularly to ensure full compliance.
3. The practice of radio-called a competent person to ask for approval for permit/certificate and then signed by anotherparty shall be stopped.
4. Inadequate communication and coordination between different turnaround teams and contractors during execution of works could result in miscommunication and different understanding of an intent.
5. Established lock-out and tag-out procedure shall be strictly enforced including use of tag, dedicated locks and key box for control of issuance of locks & keys.
6. Correct method of applying earth bonding clamps shall be used.
7. If you are working on an electrical equipment, never assume it is de-energised unless tested and confirmed byyourself.
Location Of Incident : Kuantan, Malaysia
Date Of Incident : 24th July, 2005
Brief Account Of Incident
A lost time injury incident occurred when a contractor worker was exposed to a severe electrical flash-over while servicing the 11KV cable connection bar in a substation during a turnaround.
Outcome
First degree burn due to severe electrical flash-over.
Active Failures
The Active Failure leading to the incident was the 11KV cable connection bar was still energized when the contractor worker applied the earth bonding clamps resulting in a severe electrical flash-over.
Lessons Learned
1. Two separate PTWs were issued for the same activity:
i) servicing of front and back portion of switchboard and
ii) switching for isolation of front portion of the switchboard. A single PTW shall be issued for one activity and the switching for isolation shall be recorded in the Electrical Isolation Certificate.
2. The following shortcomings were observed in permitting processi) PTW – electrical hazard not identified, inadequate precautions & electrical PPEs not specified and contractorworker did not signed andii) Electrical Isolation Certificate – Lock-out and tag-out section not filled, Competent Person signing is not qualifiedBO and inadequate briefing/communication between issuer and receiver. The established PTW procedure shall bestrictly enforced and audited regularly to ensure full compliance.
3. The practice of radio-called a competent person to ask for approval for permit/certificate and then signed by anotherparty shall be stopped.
4. Inadequate communication and coordination between different turnaround teams and contractors during execution of works could result in miscommunication and different understanding of an intent.
5. Established lock-out and tag-out procedure shall be strictly enforced including use of tag, dedicated locks and key box for control of issuance of locks & keys.
6. Correct method of applying earth bonding clamps shall be used.
7. If you are working on an electrical equipment, never assume it is de-energised unless tested and confirmed byyourself.
15 June 2006
Cutting Work Incident
Safety Incident Topic : Cutting Work
Location Of Incident : Lingen, Germany
Date Of Incident : 19th August, 2005
Brief Account Of Incident
A worker from an outside contracting company (a repair company for steam boilers) was given the task of separating some steel pipes from a bundle of superheater pipes (1a) in Steam Boiler 2. To cut the pipes he used an angle grinder (P=2.2KW) with a cutting disk (D=230mm). When he was cutting out his third pipe, he put the angle grinder to the pipe at a height of about 1.8 m from the work platform. He switched the angle grinder to continuous operation mode. The pipe began to work loose whilst he was cutting through it and the cutting disk got stuck. The angle grinder recoiled and hit the workman on the left side of his chest. The angle grinder lodged in his work clothing. A colleague who was present prevented any further injury by switching the power off. The injured man was able to climb down from the scaffolding and leave the enclosed space unaided. The security guards called the ambulance men, who carried out first aid on him before taking him to the local hospital.The man was discharged after receiving treatment in the outpatients department, and the following day he was given lighter work to do (RWI).
Outcome
- Lacerations in the left chest area which responded to medical treatment in hospital (MTC).
- If the injury had been to his neck, the accident would have to have been classified as a major incident (MIA).
Possible Immediate Causes
- Unfavourable working position.
- The man was overtaxing his body at the time.
- Incorrect cutting sequence. (The first cut should have been in the lower section).
- The decision to start cutting at the top was the wrong one.
- It was a seemingly easy routing task and the man had not thought it through properly).
- Noise was a hazard. The pipe was under tension. The tools / working environment presented a mechanical hazard.
- The working position and ambient temperature were ergonomically unfavorable.
Possible Causes in the System
- Exhaustion as a result of the work load.
- Reduced performance as a result of the high room temperature.
- The man felt he had to finish the job quickly.
- The contracting company’s system for informing employees about work-related incidents is capable of improvement.
What Went Wrong
- The pipe which was to be cut out was under tension.
- In the position where it was, the angle grinder could not be operated safely.
- The angle grinder had been switched over to continuous mode.
What Went Well
- His colleague was on the spot to offer immediate help.
- The security guard had the workmen in view and was able to alarm the emergency services at the refinery immediately.
- The rescue team worked quickly and professionally.
Lessons learned
- It is important not to underestimate potential hazards from routine jobs.
Recommendations
- Select prudently when choosing which tools to work with.
- Angle grinders should not be switched to continuous mode when working in an unusual position.
- Before each separate stage in the work, the workmen must assess the possible dangers, independently of the ambient conditions, and should take the necessary preventive steps.
Location Of Incident : Lingen, Germany
Date Of Incident : 19th August, 2005
Brief Account Of Incident
A worker from an outside contracting company (a repair company for steam boilers) was given the task of separating some steel pipes from a bundle of superheater pipes (1a) in Steam Boiler 2. To cut the pipes he used an angle grinder (P=2.2KW) with a cutting disk (D=230mm). When he was cutting out his third pipe, he put the angle grinder to the pipe at a height of about 1.8 m from the work platform. He switched the angle grinder to continuous operation mode. The pipe began to work loose whilst he was cutting through it and the cutting disk got stuck. The angle grinder recoiled and hit the workman on the left side of his chest. The angle grinder lodged in his work clothing. A colleague who was present prevented any further injury by switching the power off. The injured man was able to climb down from the scaffolding and leave the enclosed space unaided. The security guards called the ambulance men, who carried out first aid on him before taking him to the local hospital.The man was discharged after receiving treatment in the outpatients department, and the following day he was given lighter work to do (RWI).
Outcome
- Lacerations in the left chest area which responded to medical treatment in hospital (MTC).
- If the injury had been to his neck, the accident would have to have been classified as a major incident (MIA).
Possible Immediate Causes
- Unfavourable working position.
- The man was overtaxing his body at the time.
- Incorrect cutting sequence. (The first cut should have been in the lower section).
- The decision to start cutting at the top was the wrong one.
- It was a seemingly easy routing task and the man had not thought it through properly).
- Noise was a hazard. The pipe was under tension. The tools / working environment presented a mechanical hazard.
- The working position and ambient temperature were ergonomically unfavorable.
Possible Causes in the System
- Exhaustion as a result of the work load.
- Reduced performance as a result of the high room temperature.
- The man felt he had to finish the job quickly.
- The contracting company’s system for informing employees about work-related incidents is capable of improvement.
What Went Wrong
- The pipe which was to be cut out was under tension.
- In the position where it was, the angle grinder could not be operated safely.
- The angle grinder had been switched over to continuous mode.
What Went Well
- His colleague was on the spot to offer immediate help.
- The security guard had the workmen in view and was able to alarm the emergency services at the refinery immediately.
- The rescue team worked quickly and professionally.
Lessons learned
- It is important not to underestimate potential hazards from routine jobs.
Recommendations
- Select prudently when choosing which tools to work with.
- Angle grinders should not be switched to continuous mode when working in an unusual position.
- Before each separate stage in the work, the workmen must assess the possible dangers, independently of the ambient conditions, and should take the necessary preventive steps.
Release Of Hydrocarbon
Safety Incident Topic : Release Of Hydrocarbon
Location Of Incident : Hull, UK
Date Of Incident : 20th April, 2006
Brief Account Of Incident
During the start-up of the dehydration section of the DF2 plant, approximately 30tes of DIPE (Di-isopropylether) and 53tes of Acetic Acid were released in to the plant’s open channel trade effluent system from the base of steam stripper C205. This release began when C205 was started up with valve ‘A’ in the open position. This valve is normally closed during start-up and normal operation of the unit as referenced in the local procedures. With this valve open, C205 was gradually over-loaded with hydrocarbons and experienced high operating pressures. To maintain the start-up and prevent C205 tripping on high-pressure, the control temperature was deliberately kept low, leading to the loss of hydrocarbons from C205 base to effluent. Short duration pressure spikes had been experienced during start-ups on C205 in the past and the duty shift team felt that the column would recover (as previously) if left operating in this manner. Limited plant reviews took place to determine the cause of this sustained poor control.
DIPE is used in this part of the process to break the Acetic Acid/water azeotrope. Normally, with valve ‘A’ closed, water (with residual hydrocarbons) flows from the base of liquid-liquid separator C213 to the E204 condensers before undergoing further separation in decanter D204. With valve ‘A’ open the system hydraulics allow back-flow of condensed hydrocarbons from the overheads of the Azeotrope column C204, directly in to C205. This was initially DIPE, but later became rich in Acetic Acid when the reflux back to C204 was lost.
High TOC levels were first recorded by a local effluent on-line analyser at 19:55hrs on the 20th April and were further confirmed by spot sample effluent results (that were being taken every four hours) and continued until the unit was shutdown and isolated at 08:09hrs on the 21st April. Effluent had already been diverted to on-site storage before this event, so operating teams were confident there would be no breaches of consent.
Potential Outcome
DIPE is a highly flammable immiscible hydrocarbon solvent with a low specific gravity, so readily floats on water. C205 base drops in to an open channel that passes through the plant before reaching the local effluent pit. With such a large quantity of highly flammable material in an open channel, there was the potential for combustion with resulting escalation.
What Went Wrong (Critical Factors)
· Engineering/Design. Valve ‘A’ should not have been open at start-up. The valve was not part of a locked closed valve register. Potential back-flow from E204 had not been recognised in any previous process safety studies.
· Inattention/Lack of Awareness. Failure to adequately respond to high TOC levels from both on-line analysis and spot sample results and failure to appreciate volumes of hydrocarbons involved. Limited plant investigation took place.
· Communication. Local Shift Site Manager (SSM) was not informed. Duty shift teams did not use local procedures for guidance on the actions to take on activation of high TOC alarm.
· Poor judgement. Mistrust of local TOC analyser. Persistent operation of C205 at low temperatures to avoid high pressure spikes/trips, believing column control would recover naturally.
What Went Well
· There were no breaches of consent, as effluent was already diverted to on-site storage as part of the plant re-start.
· The DIPE was recovered in the DF2 local effluent system and removed for off-site disposal.
Lessons Learned
· To immediately investigate and respond to any unexpected sustained rises in local effluent TOC results from on-line or spot sample analysis.
· To ensure process bypass valves are included in the plant’s locked valve register
· To improve communication between shift operating teams and the local SSM.
Key Messages
· To actively investigate any abnormal effluent condition and seek further support as necessary.
· Reinforce the expectation that operating teams shut the plant down rather than trying to recover from a persistent process upset condition.
Location Of Incident : Hull, UK
Date Of Incident : 20th April, 2006
Brief Account Of Incident
During the start-up of the dehydration section of the DF2 plant, approximately 30tes of DIPE (Di-isopropylether) and 53tes of Acetic Acid were released in to the plant’s open channel trade effluent system from the base of steam stripper C205. This release began when C205 was started up with valve ‘A’ in the open position. This valve is normally closed during start-up and normal operation of the unit as referenced in the local procedures. With this valve open, C205 was gradually over-loaded with hydrocarbons and experienced high operating pressures. To maintain the start-up and prevent C205 tripping on high-pressure, the control temperature was deliberately kept low, leading to the loss of hydrocarbons from C205 base to effluent. Short duration pressure spikes had been experienced during start-ups on C205 in the past and the duty shift team felt that the column would recover (as previously) if left operating in this manner. Limited plant reviews took place to determine the cause of this sustained poor control.
DIPE is used in this part of the process to break the Acetic Acid/water azeotrope. Normally, with valve ‘A’ closed, water (with residual hydrocarbons) flows from the base of liquid-liquid separator C213 to the E204 condensers before undergoing further separation in decanter D204. With valve ‘A’ open the system hydraulics allow back-flow of condensed hydrocarbons from the overheads of the Azeotrope column C204, directly in to C205. This was initially DIPE, but later became rich in Acetic Acid when the reflux back to C204 was lost.
High TOC levels were first recorded by a local effluent on-line analyser at 19:55hrs on the 20th April and were further confirmed by spot sample effluent results (that were being taken every four hours) and continued until the unit was shutdown and isolated at 08:09hrs on the 21st April. Effluent had already been diverted to on-site storage before this event, so operating teams were confident there would be no breaches of consent.
Potential Outcome
DIPE is a highly flammable immiscible hydrocarbon solvent with a low specific gravity, so readily floats on water. C205 base drops in to an open channel that passes through the plant before reaching the local effluent pit. With such a large quantity of highly flammable material in an open channel, there was the potential for combustion with resulting escalation.
What Went Wrong (Critical Factors)
· Engineering/Design. Valve ‘A’ should not have been open at start-up. The valve was not part of a locked closed valve register. Potential back-flow from E204 had not been recognised in any previous process safety studies.
· Inattention/Lack of Awareness. Failure to adequately respond to high TOC levels from both on-line analysis and spot sample results and failure to appreciate volumes of hydrocarbons involved. Limited plant investigation took place.
· Communication. Local Shift Site Manager (SSM) was not informed. Duty shift teams did not use local procedures for guidance on the actions to take on activation of high TOC alarm.
· Poor judgement. Mistrust of local TOC analyser. Persistent operation of C205 at low temperatures to avoid high pressure spikes/trips, believing column control would recover naturally.
What Went Well
· There were no breaches of consent, as effluent was already diverted to on-site storage as part of the plant re-start.
· The DIPE was recovered in the DF2 local effluent system and removed for off-site disposal.
Lessons Learned
· To immediately investigate and respond to any unexpected sustained rises in local effluent TOC results from on-line or spot sample analysis.
· To ensure process bypass valves are included in the plant’s locked valve register
· To improve communication between shift operating teams and the local SSM.
Key Messages
· To actively investigate any abnormal effluent condition and seek further support as necessary.
· Reinforce the expectation that operating teams shut the plant down rather than trying to recover from a persistent process upset condition.
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