Hydrogen release incident

 While deplugging a cooling circuit, a block-age suddenly set loose, causing an un-controlled movement of a flexible hose connected to the system. The flexible hose hit several small pipes nearby. Due to the broken pipe work there was a release of hydrogen and butene that lasted about five minutes. Sprinkler systems were activated; no ignition occurred. One employee standing nearby was hit by the flexible hose, causing a severe cut on the upper leg. The estimated production loss was 7 days.

Source: European Commission 

Sulphuric acid tank leak due to foundation collapse

On 4th February 2005 a storage tank containing 16,300 t of 96 % sulphuric acid ruptured. The entire contents of the tank were spilled out into the bund and then overflowed out into the nearby dock. The environmental consequences of the accident were quite significant, the sulphuric acid emission had a serious effect on local flora in the inner and deepest parts of the harbor and harbor entrance area. When the sulphuric acid came into contact with the salt water an exothermic reaction occurred, producing a vapour cloud consisting of hydrogen chloride that drifted northwards along the coastline in the direction of the wind. Fortunately, the wind was blowing towards the sea and away from populated land areas and the cloud diluted very quickly. After the spill approximately 2,000 t of contaminated sulphuric acid remained in the bund. The acid also soaked into about 100,000 square metres of the ground surrounding the spill. 

The cause of this incident was a leak in an underground coolant supply pipe of reinforced concrete installed over fourty years before that resulted in a weakening of the ground under the tank farm. Apparently, water forced its way out of the pipe, eroding the ground near and around the sulphuric acid tank. This erosion damaged the ground under the tank which ultimately failed due to the lack of sup-port of the tank floor. A study of the appearance of the involved part of the coolant supply pipe suggests that the corrosion was a result of an acidic attack on the concrete.

Source: European commission

Pump cavitation causes flange leak

A leakage of a hexane solution from a pump discharge flange during use occurred. The hexane vapor was ignited by a static electricity spark and a fire occurred. Apparently, the flange was loosened by vibrations from the pump, due to cavitation, which was ignored. Routine operations were being carried out on site at the time of the accident. The operation involved the transfer of a hexane solution from an unreacted raw material recovery tank to the washing process through the outlet of the first flange of the pump. The hexane solution leaked, ignited, and burned. The financial costs of recovery and lost production were significant.

Source: European Commission

OSHA CITATIONS FOR A REFINERY INCIDENT

In 2008, a blast at a propylene splitter, injured five people, including one passerby.OSHA fined the facility for the following citations:

- All plant fire protection facilities were not adequately maintained and/or periodically inspected and tested to make sure they were always in satisfactory operating condition and would serve their purpose in time of emergency. Fine: $6,300.

- Process safety information pertaining to the equipment in the process did not include the relief system design and design basis. Employees working for the propylene splitter, alkylation area, catalytic cracker, Cat Light Ends and other units relieved by this flare system were "potentially exposed to equipment failure and subsequent catastrophic release of flammable or toxic materials resulting in toxic exposure, explosion and fire hazards. Proposed penalty: $6,300.

- The process hazard analysis for the propylene splitter unit did not address engineering controls to indicate to board operators the fluid levels in the three propylene splitter towers resulting in a hazard to employees. Proposed penalty: $6,300.

- The company did not develop and implement written operating procedure that involved clear instructions for safely conducting activities. According to information from OSHA, written operating procedures used for start-up of the propylene splitter unit did not provide clear instructions for safely conducting activities, nor did they address operating limits, safety and health considerations, safety systems and their functions. Proposed penalty: $6,300.

- Frequency of inspections and tests of process equipment to maintain its mechanical integrity was not consistent with manufacturer's recommendations and good engineering practices. Also, recommended piping inspection intervals were not followed. Proposed penalty: $6,300.

- The company did not correct deficiencies in equipment outside acceptable limits before further use or in a safe and timely manner. Piping and components at the propylene unit were outside acceptable limits as defined by design codes and standards employed by the company. These design codes and standard limits were exceeded in that component set points and thinning of piping beyond safe and acceptable limits was evident in process equipment. Proposed penalty: $6,300.

- Piping inspection drawings for the reboiler area were not consistent with design specifications. Improper piping thicknesses were indicated and piping retirement thicknesses were not consistent with design specs and recommended good engineering practices. Proposed penalty: $6,300.

- The company did not investigate each incident which result in, or could reasonably have resulted in, a catastrophic release of a highly hazardous chemical in the workplace. Proposed penalty: $1,875.

- The employee alarm system did not provide warning for necessary emergency action as called for in the emergency action plan, or for reaction time for safe escape of employees from the workplace, immediate area or both. Proposed penalty: $6,300.

Source: OSHA.gov

EMERGENCY FIREWATER PUMP COULD NOT BE STARTED FROM THE BRIDGE

 https://www.imca-int.com/alert/1167/near-miss-emergency-fire-pump-not-started-bridge/

FATALITY DUE TO ASPHXYIATION IN ROCK PHOSPHATE

A worker died after getting trapped ina rock phosphate pile. Innocuous  substances also can kill you.

  https://open.alberta.ca/dataset/4dab3567-fbd0-4b5e-9620-fc3d633b377a/resource/fd5d6f93-145d-4225-8cd1-432bbc29c6f8/download/lbr-2016-06-02-carey-report-public.pdf

IDENTIFY THE HUMAN FACTORS THAT LED TO THIS INCIDENT

 https://open.alberta.ca/dataset/7071575b-9876-4c6b-8593-5789adaa84c7/resource/8f1ea562-4676-4fdd-b942-1bce0213206d/download/lbr-fatality-report-f-ohs-102998-22c81.pdf

EXPLOSION IN GAS CONDENSATE TANK

 http://wyomingworkforce.org/_docs/osha/accidents/09-23a-2014.pdf

FATAL ACCIDENT DURING FILTER CHANGE

 http://wyomingworkforce.org/_docs/osha/accidents/09-14-2016.pdf

Do not be fooled by water wells

 http://wyomingworkforce.org/_docs/osha/accidents/06-05-2018.pdf

Fire inside confined space due to halogen light

On Dec. 17, 2013, the worker was spraying a flammable coating on the inside walls of a large steel tank when a fire was ignited by a portable halogen light. The 37-year-old man was rescued but spent three days in the burn unit at Hospital.

Cal/OSHA cited the company for these and other alleged violations:

• Knowingly using an unauthorized electric lamp while the painter was working in an explosive atmosphere.
• Not having a permit to work in a confined space.
• Not having the proper ventilation or protective equipment for such a hazardous space

Source: CAL Osha

Flammable vapours + ignition = Fire

 On September 9, 2005, Employees #1 and #2 were replacing a sump pump on a premium gasoline pump at a BP Gas station. The pump, powered by a 220 volt line, was in a sump that was used to contain fuel residue. After the installation of the new pump, it was tested and failed to operate. While Employee #1 was checking the pump voltage with a volt/ohm meter, he became distracted and allowed a meter lead to short to ground. The resultant spark ignited fuel vapors in the bottom of the sump and caused a flash fire. Employee #1 sustained first-degree burns to his hands and face. Employee #2 was hospitalized first-degree burns to his face. 

Source: osha.gov

Lessons Learned from a Hydrogen Explosion

Lessons Learned from a Hydrogen Explosion: On January 8, 2007, a hydrogen explosion at the Muskingum River Power Plant’s 585-MW coal-fired supercritical Unit 5 caused one fatality, injuries to 10 other people, and significant damage to several buildings. The explosion occurred during a routine delivery of hydrogen when a hydrogen relief device failed, which allowed the contents of the hydrogen tank to escape and be ignited by an unknown source. This article covers the findings of the incident investigation and the actions the plant has taken to prevent a reoccurrence.

Small bore tubing incident

A gas leak occurred at a compressor station when small bore pipework fractured. The incident resulted in a small natural gas release that was successfully resolved without harm, although the licensee identified the potential for the situation to have escalated if it was not for the careful inspection prior to works being undertaken.The small bore pipe that failed was a low point in the drain system located in a pit that was not readily accessible.The root cause was identified as the small bore pipe that failed had not been designed to handle vibration resulting from high gas flows and decreased suction pressures. The small bore pipe’s limited accessibility resulted in it being missed on previous site reviews specifically undertaken to identify potential points of failure due to vibrations.

Source:https://www.dmp.wa.gov.au

HYDROGEN FIRED BOILER EXPLOSION

Bypassing of safety interlocks during start up of boilers have caused many explosions around the World, killing many people. I had investigated one incident where a hydrogen fired boiler was being commissioned and the trips were bypassed as they were causing some problem. The boiler exploded and the operator was killed. Read about another hydrogen fired boiler explosion in this link:

 https://www.dmp.wa.gov.au/Documents/Safety/PGS_SIR_01-2016.pdf

Explosion in molten sulphur tank

Molten sulphur tanks are often not given the importance they deserve. because of the nature of the product, they are dangerous and have to be handled with precautions. This safety alert explains the case of an explosion in an molten sulphur tank. Ensure the learnings are shared. Read the safety alert in this link:

https://epsc.be/epsc_media/Learning+Sheets/2019/19_06+EPSC+Learning+Sheet+_+H2S+explosion-p-660.pdf

Inspection frequencies and OSHA

The most commonly cited equipment for non-compliant inspection frequencies (of any type, not only thickness measurements) have been piping circuits followed by pressure vessels, relief devices, and monitoring alarms. As part of the inspection program, an appropriate inspection frequency must be established for equipment in order to determine whether pipe/vessel thickness is decreasing as expected. API 570 identifies three classes of piping services and recommends a thickness measurement inspection frequency based on the class. For example, Class 1 includes:

• Flammable, 
• Pressurized services that may rapidly vaporize and explode upon release,
• Hydrogen sulfide, 
• Anhydrous hydrogen chloride, 
• Hydrofluoric acid 
• Piping over water of public throughways, and
• Flammable services operating above their auto-ignition temperature.

As discussed in API 570, Class 1 requires a thickness measurement inspection frequency of at least every five years. Classes 2 and 3 require a thickness measurement frequency of at least every 10 years. The inspection interval for specific piping is established by the inspector or piping engineer in accordance with the owner/user’s quality assurance system, but not to exceed the limits set by API 570

Source:Osha.gov

OSHA ASSET INTEGRITY OBSERVATIONS

Examples of equipment cited for violations of the PSM MI requirements that OSHA found during NEP inspections include:

• A broken gate valve caused a level gauge to not work properly, which rendered visual verification of liquid level for the vessel ineffective. This deficiency went uncorrected.
• The installation of an engineered clamp failed to correct a deficient piece of process piping, which was a 90-degree elbow that was outside acceptable limits. The employer continued to use the leaking 90-degree elbow as part of a piping circuit that conveyed waste hydrogen sulfide gas.
• Hydrogen sulfide monitors were not inspected and tested on a regular basis to correct deficiencies in alarms that were outside acceptable limits due to bad sensors, loose wiring, or monitors that needed to be replaced. Work orders were not managed by a tracking system to ensure that deficiencies were fixed in a timely manner. Some work orders marked “fix today” or “ASAP” were not fixed for a week or longer.
• Six relief systems in an alkylation unit were incorrectly sized and were not corrected in a timely manner when the deficiencies were reported. No Management of Change (MOC) was performed to justify the decision to delay replacing the deficient systems.
• Grounding cables were removed from equipment, such as a heat exchanger and pump motors, but were not replaced. 
• Excessive vibration was observed on motors with visible movement of structural steel decking and supports. Also, two 1” pipes and one 4” pipe containing flammable liquid were not adequately supported

Source: Osha.gov

ASSET INTEGRITY ISSUES

Failure to correct equipment deficiencies that are outside acceptable limits39 is one of the leading causes of PSM non-compliance in the petroleum refinery sector. Non-compliance for equipment deficiencies broke down into four major groups:

1. Lack of proper maintenance or repair, 38. 29 CFR 1910.119(j)(1)(i)-(vi)39. 29 CFR 1910.119(j)(5)OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION18
2. Inappropriate installation (such as inappropriate sizing),
3. Missing protective system (such as not including relief devices), and
4. Insufficient structural support.

Equipment most commonly cited for deficiencies were relief devices, followed by piping circuits, pressure vessels, and alarm systems.

Source:Osha.gov

 

Dust collector system explosion

Employee #1 was feeding 400 lb of granular polyalphamethyl styrene (CAS 25014-31-7) through a Mikropal #3 micropulverizer (equipped with a .032 in. screen) into a Mikropal Mikro-Pulsaire dry dust collector. The Mikro-Pulsaire unit has a continuously self-cleaning bag filter located inside the building and had no provision for explosion relief or venting. Apparently a piece of metal between 1 and 2 in. got past the magnet in the micropulverizer, ignited the dust in the system, and caused a fire and explosion that blew open the access door to the dust collector. Employee #1 was standing about 10 ft from the door and sustained second- and third degree-burns on his hands and face. 

Source:Osha.gov