The employees were charging a furnace for an alloy melt. Employee #1 had just placed the final two pigs on the lip of the furnace door and had backed his lift truck at an angle to a distance of 15 feet from the furnace. Employee #3 had previously pushed seven pigs into the furnace. As he pushed the final two pigs into the furnace, there were two separate explosions inside the furnace. The first explosion caused a wave of molten metal to flow over the open furnace sill outward to a distance of 40 feet. The second explosion caused a fan shaped flame that extended out 80 feet from the furnace. The flame touched the left front of Employee #1's lift truck and completely engulfed Employee #3's lift truck (located 30 feet directly in front of the furnace). Employee #2 was standing behind Employee #1's lift truck. All three employees were burned. Employee #3 died of his injuries. Water pockets inside the pigs apparently caused the explosions.

 Source: osha.gov

 Top Ten Boiler and Combustion Safety Issues to Avoid

 John R. Puskar, P.E.
Principal and Owner of CEC Combustion Services Group

Category: Operations

Summary: This article was originally published in the Summer 2010 National Board BULLETIN.

 https://www.nationalboard.org/Index.aspx?pageID=164&ID=439

 A game-changing approach to furnace safeguarding

This work is a follow-up article to “Automate furnace controls to improve safety and energy efficiency,” which was published in the June 2014 edition of Hydrocarbon Processing.

Mickity, D., Phillips 66

 

https://www.hydrocarbonprocessing.com/magazine/2018/september-2018/special-focus-refining-technology/a-game-changing-approach-to-furnace-safeguarding

 

Role of fired heater safety systems

A fully automated burner management system operating as a SIS for burner control can meet minimum safety targets, improve system availability and lower costs

NIKKI BISHOP and DAVID SHEPPARD
Emerson Process Management

Role of fired heater safety systems

Design Options for Overfill Protection for Aboveground Atmospheric Tanks - Best Practices

"Overfilling of a tank is an important safety hazard.  It may result in loss of tank fluid and potentially severe consequences if the fluid is flammable or environmentally sensitive.   Additionally, it is necessary to preserve the mechanical integrity of a tank.   This article first looks briefly at various ways liquid may overfill a tank, and then describes different design options as best practices to take care of situations where overfilling is a possibility.   The main paper will contain diagrams and appropriate references."

 See this link https://www.aiche.org/academy/videos/conference-presentations/design-options-overfill-protection-aboveground-atmospheric-tanks-best-practices

DONT UNDERESTIMATE OVERFILLING RISKS

 "Loss of level control has contributed to three significant industrial incidents:

 In Australia, the Esso Longford explosion in September 1998 resulted in two fatalities, eight injuries, and A$1.3 billion (more than U.S. $ 1 billion) in losses [1];In the U.S., the BP Texas City explosion in March 2005 caused 15 fatalities and more than 170 injuries, profoundly affected facility production for months afterwards, and incurred losses exceeding $1.6 billion on BP [2]; andIn the U.K., the Buncefield explosion in December 2005 injured 43 people, devastated the Hertfordshire Oil Storage Terminal, and led to total losses of as much as ₤1 billion (about $1.5 billion) [3, 4]."

Read the article at https://www.chemicalprocessing.com/articles/2010/143/

2019 Significant Process Safety Incidents

2019 Significant Process Safety Incidents: Use this summary of 2019's process safety incidents to learn and to help prevent incidents at your facility, whatever your industry. This video is a summary of significant process safety incidents during the year 2019. The purpose of maintaining awareness and sharing process safety incidents each year is to promote the Risk Based Process Safety (RBPS) approach to lessons-learned and to encourage industry to maintain a sense of vulnerability. This allows our members to be up to date on the latest news regarding process safety as we strive to be strong, smarter, and more effective in the ongoing effort to reduce process safety incidents to zero.

Alarm floods and plant incidents

Most of the incident investigations performed by the US Chemical Safety Board (CSB) cite alarm floods as being a significant contributing cause to industrial incidents. In fact, alarm management has become identified as one of the key issues listed on the cover of recent CSB investigation reports. The British-based organisation Engineering Equipment & Materials Users’ Association (EEMUA) came to the same finding in its report from 1999 when it analysed major incidents around the world, including Three Mile Island, Bhopal and Texaco Milford Haven.¹ Therefore, the connection of alarm floods to incidents has been well documented for over 12 years. On the whole, industrial progress controlling floods in those 12 years has been nil. Many corporations and plant locations are attempting to do so, but many engineers, including alarm management vendors, do not know what it takes to control floods under all operating conditions. This article shows examples of good alarm management programmes and how they successfully control alarm floods under all operating conditions.

 Read the article at Alarm floods and plant incidents

SIL and functional safety in rotating equipment

 SIL (safety integrity level) is a very important safety indicator that has been extensively discussed, described and often misunderstood within the industry over the past years. The purpose of this article is to provide operators, reliability engineers, instrumentation engineers and department managers with a practical overview of the areas where SIL and functional safety are important in their daily business life. Note that, in the light of the International Electro-technical Commission (IEC) and most other safety relevant standards, risk is strictly defined as “harm to health safety environment” (HSE).

 Read more at SIL and functional safety in rotating equipment

Process safety time for fired heaters

The fired heater is a common unit operation in the refining and petrochemical industries that is used to increase the temperature of a process fluid. Fired heaters are required when a process-to-process heat exchanger or a utility exchanger (steam condenser, hot oil heater) cannot provide sufficient driving force to raise the temperature of a process fluid for downstream processing. There are numerous applications for fired heaters, from preheating feed to process units to reboiling distillation towers.

During the course of normal operation a fired heater will be exposed to disturbances in the supply of fuel, combustion air, or process fluid that may lead to a potentially hazardous condition developing. To manage these disturbances and take appropriate action to safely operate and control the fired heater, several layers of protective systems are normally provided.¹ These protective systems are designed to take independent action that will prevent the fired heater from reaching a hazardous condition.

 Continue reading at Process safety time for fired heaters

REFINERY FIRE INCIDENT

Incident at Visakh Refinery Date of incident : 23.08.2013 Time: 16:46 hrs Entity: HPCL Location: VRCFP Cooling Tower, Visakh Refinery, Vishakhapatnam

Description:On August 23, 2013, one of the cells of the Salt Water Cooling Tower of Visakh refinery was being commissioned. During the opening of the water line at about 16:46 hours, there was a minor explosion and fire. The cooling tower burned down and collapsed. Due to the fire, workers working near other cells and surrounding area sustained burn injuries. There was one fatality (company employee) and 39 persons sustained injuries and were shifted to INS Kalyani and other hospitals in the city. On the next day, another 6 dead bodies were found in debris. 

Observation:

•One new cell was added to the existing cooling tower, and the existing cells were under maintenance.

•Hot jobs were going on in the nearby area.

•The ingress of hydrocarbon in the cooling water was due to leakage of cooler / condenser in process units connected with this return line.

•There was imbalance in load of two distribution headers on the top of cooling tower cells. To reduce the load on the cooling towers, a process modification scheme was issued whereby the cooling water return headers were proposed to be re-routed to the ground level and construction of riser pipes from the bottom header to the top of each cell, for uniform supply of hot cooling water to the Cooling Tower. With this, the load of return header, which earlier was on top of the cell, would be shifted from Cooling Tower structure to the separate supports outside the Cooling Tower.

•There is distinct possibility of entrapped / accumulated light hydrocarbon in the portion of the new line since it is located at an elevation and that there was no escape route for this entrapped hydrocarbon as the other end of the header was closed by valve.

•The entrapped hydrocarbon gushed into the Cooling Tower as soon as the cooling water return line valve to the new cell was opened. The hydrocarbon got ignited by the spark of welding jobs being carried out nearby causing explosion and major fire. The wooden structure of the Cooling Tower got ignited in the process which continued for about 45 minutes till the fire was extinguished by F&S personnel.

•The accident resulted in serious burn injuries and fatality to a number of persons working in the cooling tower area.

Cause:

•Gushing out of entrapped hydrocarbon from the cooling water return header to newcell, which got ignited since hot jobs were being carried out in close vicinity. The ingress of hydrocarbon was due to leakage of hydrocarbon in cooler/condenser in connected process units.

•Not adhering to the practice of stopping all work (especially hot work) and prohibiting all unrelated contractor and company personnel at site, before commissioning a new system/ facility. Also, carrying out hazard analysis/ risk assessment would have probably indicated that there could be trapped HC gas, and prompted commissioning/ operation team to vent out entrapped gases.

•Undertaking commissioning activities, even though several jobs were unfinished: HC and H2S detectors were not installed. Instrument cabling, cooling fan jobs were still unfinished.Decision to go ahead with commissioning was taken at fag end of the day.Improper coordination amongst Operation, Maintenance and Project departments.Non – liquidation of the gaps identified in internal safety audit & operation check-list before commissioning.

Recommendations:

•Do not allow simultaneous hot work and commissioning activity at site as this increasemanifolds the chances of accidents.

•While commissioning activity is planned/ undertaken, it must be ensured that other than the required personnel, nobody should be allowed to be present at the work site.

•Hazard analysis must be done prior to commissioning of any new facility.

•Hazard Identification and Risk Assessment must be carried out before commissioning of any new/ temporary facility / system; this analysis by a multi-disciplinary group can easily identify the risks involved and suggest measures to overcome the same.

•Facility(s) must not be commissioned unless pre-com audit is carried out.•No facility should be commissioned unless it is ensured that internal audit points / precom check-list points are liquidated; further a multi-disciplinary group must carry out the internal audit.

•There must be a proper coordination amongst the various departments; in the instant case there was clear communication gap and lack of coordination amongst Operation, Project and Maintenance Departments.

•No facility must be commissioned unless safety devices like Hydrocarbon or Hydrogen Sulphide detectors are installed.

•Standard Operating Procedure must be prepared; shared with operating personnel and ensured its display at site prior to commissioning.

•Proper house-keeping must be done at the commissioning site; the site should be clear of unwanted materials and debris.

Source: https://www.pngrb.gov.in/pdf/ERDMP/Analysis of incidents reported to PNGRB from July 2013 to Dec 2014

Incident due to ineffective PSM system

 OSHA's inspection identified several serious deficiencies in a company's process safety management program, a detailed set of requirements and procedures employers must follow to proactively address hazards associated with processes and equipment that involve large amounts of hazardous chemicals. In this case, the chemical was acetone, used in a PSM-covered process known as direct solvation. On the day of the explosion, a valve on a transfer line inadvertently was left open, resulting in the release of flammable acetone vapors. The vapors exploded after being ignited by an undetermined source.

"In this case, the company knew from prior third party and internal compliance audits conducted at the plant that aspects of its PSM program were incomplete or inadequate, and misclassified electrical equipment was in use. The company did not take adequate steps to address those conditions,"

"Luckily, the explosion happened when there were few workers in the plant. Otherwise, this incident could have resulted in a catastrophic loss of life."

Specifically, OSHA found that the process safety information for the solvation process was incomplete. The employer's analysis of hazards related to the process did not address previous incidents with a potential for catastrophic results, such as forklifts that struck process equipment, and did not address human factors such as operator error, communication between shift changes and employee fatigue from excessive overtime. In addition, the company did not ensure that a forklift and electrical equipment, such as a light fixture, switches and a motor, were approved for use in Class 1 hazardous locations where flammable gases or vapors are present. 

Source:OSHA.gov

Hydrogen leak incident

A hydrogen leak at the flange of a 6-inch synthesis turbocharger valve in an ammonia production plant ignited and exploded. Hydrogen detectors and the fire alarm alerted the control room, which immediately shut down the plant, and the fire was then extinguished rapidly. There were no injuries caused by the accident, since the operator heard a wheezing sound and was able to run away just before the explosion occurred. The leaking gas was composed of 70% hydrogen at a flow rate of 15,000 cubic meters per hour. Property damages in the turbocharger included electrical cabling, melted siding, and heavily damaged pipes. The ammonia plant was shut down for more than a month.Five days before the incident, a problem with the CO2 absorber column led operators to open the vent downstream of the column. In retrospect, this excessive venting was an operational error. It caused a reduction in the suction pressure of the ammonia synthesis turbocharger and the activation of the plant emergency stop. The relief valve on the line between the turbocharger and the methanation reactor was then exposed to high pressure, causing it to open without the operator noticing. Production resumed the next day, but abnormal consumption of syngas led the operator to conduct further investigations. He discovered that the valve was no longer leak-proof and was allowing the gas to escape through a 47-meter chimney. The plant was shut down again to replace the relief valve.When the plant was restarted, the methanation reaction was initiated at 10:00 PM, the synthesis turbocharger started operating at 1:30 AM, and the incident occurred at 3:14 AM on the flange of the newly installed 6-inch-diameter valve. The incident was caused by vibrations in the relief valve, resulting in the quick release of the flange screws, which were probably not tightened sufficiently. In addition, when the relief valve was replaced, it was probably under-calibrated.

Source:https://h2tools.org/lessons/hydrogen-leak-ignites-and-explodes-ammonia-production-plant

Cryogenic incident

 What Happened?

A researcher inserted metal racks into a liquid nitrogen tank when her right hand came into contact with the chemical; she sustained cold burns to her index, middle and ring fingers. The researcher reported the incident immediately to her PI, and went to the emergency room for medical attention. At the time of the incident the researcher was wearing appropriate PPE including a pair of latex gloves underneath the cryogenic gloves; however, the chemical had penetrated the gloves upon submersion.
What Was The Cause?

The cryogenic gloves worn by the researcher appeared to be intact. Cryogenic gloves are meant to handle cold items and protect to temperatures as low as -162°C (-260°F). However, they are not meant to be submerged into liquid nitrogen which has a temperature of −196 °C ( −321 °F). In addition, if the gloves were used for other purposes where they get wet, the problem can be compounded. Not all cryogenic gloves are water-resistant.
 

What Corrective Actions Were Taken?
• Review the correct use of cryogenic gloves and modify SOP for handling cryogenic chemicals
• Review modified SOP with lab members
 

How Can Incidents Like This Be Prevented?
• Make sure to use all equipment according to their specifications

 

Source: https://cls.ucla.edu/

High pressure water can kill

 At 5:45 p.m. on April 29, 2018, an employee was inspecting a leak beneath a valve. The employee was struck by high pressure water at 2,200 psi when the valve failed and came off, penetrating his upper torso. The employee was killed. 

Source:osha.gov

Hydraulic hose incident

 At 6:15 p.m. on November 20, 2017, an employee was working on a hydraulic leak on Filter Press #1 at the Pollution Control Plant. The employee was struck on the left side of his head by a high pressure hydraulic hose which was released from a tee fitting. The employee sustained trauma to the head when struck by the high pressure hydraulic hose fitting and was killed. 

Source:osha.gov

Hydrogen explosion

 At 9:23 a.m. on November 17, 2018, an employee was stabilizing magnesium metal. Magnesium is reacted with water to make magnesium oxide, which is a more stable compound. During this process hydrogen and oxygen are released. The hydrogen ignited and in the presence of oxygen and created a large explosion. The employee was killed. 

Source:osha.gov

Ammonia incident

 On January 10, 2020, Employees #1 and #2 were working from a scissor lift and dismantling an ammonia blast freezer in preparation for installing a new freezer. As they worked, ammonia was released. Employee #1 was killed by the chemical exposure. Employee #2 self-rescued, but was seriously injured. He was transported to the hospital and treated for severe burns and inhalation injuries. 

Source:osha.gov

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Hydrogen Sulphide accident

 At 11:00 a.m. on July 7, 2017, Employee #1was attempting to dislodge a 24 inch rubber plug from a 2foot diameter sewer pipe located inside a 24foot deep wet well. The workers were outside the well pulling on a 1/4-inch nylon rope that was attached to the 24-inch diameter plug. The plug was lodged inside a T-shaped PVC fitting from the force of the waste water emptying into the well. Without conducting any atmospheric testing of the work space, Employee #1 climbed down the ladder with a crowbar to dislodge the deflated 24inch diameter rubber plug, which was about 8 feet below the top of the well. He had difficulty releasing the plug with the crowbar and started to make his way up the ladder. He lost consciousness when he was about 2 feet from the top of the well and fell into the 24 foot deep well. Employee #2 descended down the ladder to provide emergency rescue, but lost consciousness and went underwater. The waste water level was about 3 feet deep at this point. Employee #3 climbed down the ladder to provide emergency rescue, but consciousness as well. All three workers were asphyxiated by hydrogen sulfide (H2S) gas. 

Source: osha.gov

Confined space incident

 At 12:30 p.m. on February 20, 2020, Employee #1, employed by a structural steel fabricator and erector company, was entering a tank to clean it. The tank had a combination of Ecocure II and methyl ethyl ketone (MEK) residues and had been purged with nitrogen. Employee #1 entered the permit required confined space that contained the residual chemicals and nitrogen to perform the cleaning operations. She was overcome by the oxygen deficient atmosphere. Employee #2, employed by a chemical distribution company, entered the tank to make a rescue attempt for Employee #1. He was also overcome from the oxygen deficient atmosphere. Both employees were killed by asphyxiation. 

Source:osha.gov

SUSBCRIPTION TO MY POSTS BY EMAIL - CHANGE

For those of you who have subscribed to receive my posts through e-mail, please be informed that for continued delivery to your inbox, you will have to subscribe again in the box on the right of this post.

If you do not do this, you will stop receiving my posts through e-mail.

Thank you for your co-operation.

Hazards of hydraulic accumulators

 https://www.machinerylubrication.com/Read/30331/hydraulic-accumulators-dangers

Fluid power incidents

 Fluid power incidents

Vacuum pump explosion in a lab

 Vacuum pump explosion in a lab

Learn from this incident

Employee #1 and several coworkers were working at a chemical plant that deals with nitric oxide. On the day of the accident, a major leak occurred in a stainless steel distillation column. The nitric oxide leaked into the facilities surrounding vacuum jacket and into the atmosphere through a pump, which controls a high quality vacuum inside the jacket to minimize transmission of heat toward the cryogenic distillation columns. A brown cloud quickly formed and the temperature and the pressure inside the distillation column and its surrounding vacuum jacket began to rise. The leak was detected and the vacuum pump was turned off to halt the leakage of nitric oxide into the atmosphere, allowing the pressure inside the column and vacuum jacket to stabilize around 130 psi. Although stabilized, the pressure was far above the normal pressure of less than or equal to atmospheric pressure (14.7 psi). Approximately 3 hours later, an explosion occurred. The operation and process were destroyed, and debris flew through the plant. Employee #1 suffered lacerations due to flying glass and was treated at a local hospital, where he received stitches and then released. A detailed investigation determined that the cause of the explosion was most likely due to something inside the vacuum jacket initiated the dissociation of nitric oxide, a reaction that is very rapid, exothermic, and self-propagating once started. 

Source:OSHA.gov

Accident due to a change implemented during an emergency

Reactor #1, part of the ABS polymerization process began to overheat as the viscosity increased and threatened to stop agitation. This would cause a runaway reaction and ultimately result in an explosion. A small leak had developed in the lower bushing of the agitator and the employer instructed an employee to tighten it with a wrench. The employer replaced the normal feed (a mixture of styrene monomer, ground rubber, and acrylonitrile) with pure styrene monomer, which has a much lower viscosity, to "flush" the process in the hope that this would stop the leak. The mixture began to spill through the lower agitator packing and at approximately 2:30 p.m., there occurred a major spill of styrene monomer (flammable) and acrylonitrile (flammable and carcinogenic). They evacuated the plant and called for outside assistance to stop the spill and initiate clean-up. 

Source: OSHA.gov

How fragile is your plant?

 How fragile is your plant?

Employee Killed By Inadvertently Drinking Acid Cleaning Fluid

At approximately 9:30 a.m. on October 3, 2002, an employee who worked for a company that provided vehicle maintenance such as car washes, detailing, fueling, and lube and oil servicing, inadvertently drank acid from a plastic spray bottle while he was on a rest break. The employee, feeling very ill after ingesting the contents of the quart bottle, asked his coworkers to transport him to the hospital. He was taken to San Antonio Community Hospital where he was pronounced dead at 11:49 a.m. from internal injuries. Laboratory analysis indicated that the acid solution in the plastic bottle contained hydrofluoric acid and phosphoric acid with a pH of less than one. 

Source:osha.gov

Employee dies in explosiove reaction

 At 12:00 p.m. on November 5, 2019, Employee #1 was making a small spot weld on a piece of metal. He was performing the weld on a drum of that contained flammable windshield washer fluid. There was an explosive reaction, and the cover of drum hit the employee's face. Liquid splashed on the employee and was ignited by the explosion. Employee #1's clothes caught on fire. He sustained body burns and was killed. 

Source:osha.gov

Be careful while excavating

 At 8:30 a.m. on August 1, 2020, Employees #1, #2, and #3, employed by a electrical services company in the telecommunications field, were working on a multi-employer construction project at the intersection of two streets. They were potholing to locate underground utility lines, with the aim to then bore in a new fiber optic line under the intersection. After finding what they thought was over-pour from the concrete curb, they used a Ring-o-matic Vacuum Excavator to excavate over top of the concrete. They then used a jackhammer on the concrete. The jackhammer bit made contact with a 12,470-volt underground electrical distribution line, and an electric arc explosion occurred. Employees #1 and #2 were killed by electrocution. Employee #3, who was knocked down by the force of the explosion, was transported to the hospital, where he was observed, determined to have no injuries, and released. 

Source:osha.gov

Employee injured by pressurised gas release

 At approximately 9:00 p.m. on August 8, 2006, Employees #1 and #2 attempted to clean out a heat exchanger. The heat exchanger was part of a natural gas piping system in the power generation facility of a wastewater treatment plant. The heat exchanger contained methane and natural gas, pressurized to approximately 300 pounds per square inch. Approximately 200 parts per million of hydrogen sulfide contaminant was present in the natural gas. The natural gas piping system contained two compressors, labeled Compressor A and Compressor B. The heat exchanger that Employees #1 and #2 were to clean out was connected to Compressor B. Compressor B was off and Compressor A was running. Employees #1 and #2 incorrectly assumed that since compressor B was not running, it had already been isolated from Compressor A by a closed valve. However, the valve between compressor A and B was in the "open" position. Employee #2 began removing a plug on the Compressor B heat exchanger, with a pneumatic impact gun, while Employee #1 was standing directly behind him. When the heat exchanger plug was removed, the pressurized natural gas came out of the 0.5-inch plug opening and blew Employees #2 and #1 back. The natural gas did not ignite. Employee #1 was rendered unconscious from the impact. Employee #2 initiated emergency shutdown of the natural gas system and notified other employees about the emergency. An ambulance was called, but neither employee was hospitalized. 

Source:osha.gov

Employee dies after falling into sulphuric acid tank

 At 12:30 a.m. on February 9, 2019, an employee was reaching into a steel pickling tank containing 160 degree Fahrenheit sulfuric acid in order to retrieve a sample of the solution with a hand held plastic syringe.The employee stepped onto the ledge of Pickle Tank #5, used his right hand to reach into the tank to pull the sample while simultaneously holding on to an adjacent hand railing for stability and balance with his left hand. The employee fell into the tank and was submerged. The employee remained in the tank for approximately 1 minute before being recued. He suffered from chemical and thermal burns that resulted in his death. 

Source: osha.gov

Why checking the line up before admitting chemicals is important

 At 8:00 a.m. on March 13, 2019, an employee was working for a manufacturer of basic organic chemicals. He was opening a valve to permit the flow of hexamethylenediamine (HMD). The valve had been actuated to rinse and purge feed lines. It had been left open by the previous shift. The employee forgot to check valve positions before opening the HMD flow valve. He was sprayed with HMD, and he suffered second-degree burns to his groin. He was hospitalized. 

Source:osha.gov

Two Employees Receive Corrosive Burns From Sanitizing

 At 12:00 p.m. on April 19, 2019, Employee #1 and Employee #2 were observing a food establishment's sanitation and cleaning process during an investigation. During the observations of the employees and processes, they used a foaming cleanser, quaternary ammonium, and a spot acid clear for cleaning and sanitizing. A pungent smell believed to be chlorine was being released into the air. Employees #1 and #2 noted that their eyes, skin, and mucosal linings of the mouth, throat, and nose were irritated and burning. Employee #2 measured the quaternary ammonium solution, and it was found to be in excess of 200 PPM, which is higher than recommended levels. Hospitalization was not required. 

Source:osha.gov

Chloride induced stress corrosion cracking of stainless steel thermowells: Potential for ingress of atmospheric moisture

 https://www.hse.gov.uk/safetybulletins/thermowell-corrosion.htm

External chloride stress corrosion cracking of stainless steel

 https://www.hse.gov.uk/safetybulletins/lokring-pipe-connectors.html

CONDENSATE INDUCED WATER HAMMER INCIDENT

 https://www.hse.gov.uk/safetybulletins/phenomenon-of-condensate-induced-water-hammer.htm

My presentation on Whats Going Wrong in PSM - 36 years after Bhopal?

 I am giving a presentation in the First Jordanian International Chemical Process Safety Virtual Conference to be held on 30th and 31st March 2021. My topic is "Whats Going wrong with PSM - 36 years after Bhopal?" and is scheduled on 30th March,21 between 1500 to1515 hrs Jordan time (1730 to 1745 hrs IST) The registration to the conference is free and there are very good speakers lined up. 

Register in this link http://www.jeaconf.org/JCPSC/ConferenceFees  Registration is FREE

CONFINED SPACE INCIDENT

 https://www.iadc.org/wp-content/uploads/2014/03/Safety-Alert-05-24.pdf

OSHA STANDARD FOR BREATHING AIR

OSHA Standard 29 CFR 1910.134(i)(1)
“Compressed breathing air shall meet at least the requirements for Grade D breathing air described in ANSI/Compressed Gas Association Commodity Specification for Air, G-7.1-1989, to include:
Oxygen content (v/v) of 19.5% - 23.5%;
Hydrocarbon (condensed) content of 5 milligrams per cubic meter of air or less;
Carbon monoxide (CO) content of 10 parts per million (ppm) or less;
Carbon dioxide (CO2) content of 1,000 ppm or less; and
Lack of noticeable odor”

OSHA'S RECOMMENDATIONS TO PREVENT INADVERTENT HOOKING UP OF BREATHING AIR INTO NITROGEN SYSTEMS

To help ensure that workers do not inadvertently hook up to inert gas supplies, the following recommendations should be implemented:

•Ensure that all requirements related to respiratory protection as outlined in29 CFR 1910.134 are met. Written standard operating procedures governing the selection and use of respirators must be developed and implemented. Requirements for training and instruction in the proper use of respirators and their limitations must be met at all facilities.

•Ensure (determine) that the couplings of the respirator air lines are incompatible with any other couplings/fittings for non-respirable air or gas delivery systems.Replace couplings on non-breathing air systems with another, incompatible type of coupling.

•Ensure that breathable air systems are not in any way interconnected to non-breathable air systems.

•Develop a maintenance procedure to address supply-line identification (labeling)and painting. Stress the purpose of color coding and the importance of completing detail painting in a timely fashion to ensure that this visual cue is always available to aid workers.

Source: Osha.gov

INCIDENT #3 DUE TO CONNECTING BREATHING AIR HOSE TO NITROGEN

 An employee hooked the fresh air line of his supplied-air respirator into a plant’s compressed airlines and began abrasive blasting. The plant operators, unaware that their plant air was being used as breathing air, shut down the fresh air compressor for routine, scheduled maintenance and pumped nitrogen into the system to maintain pressure and control the valves in the refinery. The employee was overcome by the nitrogen in the airlines and died of nitrogen asphyxia.

Source:Osha.gov

INCIDENT #2 DUE TO CONNECTING BREATHING AIR HOSE TO NITROGEN

An employee was using an air hammer to chip residue out of a furnace at an aluminum foundry.He was wearing an air-line respirator. Two compressed gas lines with universal access couplings were attached to a nearby post. The one on the right was labeled “natural gas.” The gas line on the left had a paper tag attached with the word“air” handwritten on it; however, this line actually contained pure nitrogen. A splitter diverted one part of the gas stream to the air hammer and the other part of the stream to the air-line respirator.The employee was asphyxiated and killed when exposed to pure nitrogen.

Source:osha,gov

INCIDENT #1 DUE TO CONNECTING BREATHING AIR HOSE TO NITROGEN

A contractor crew was assigned to abrasively blast inside a reactor vessel at a petrochemical refinery.Although verbal company policy called for contractors to supply all breathing air, this crew,with supervisor’s knowledge, had on several occasions used plant air to supply breathing air. A crew member mistakenly hooked up his air-line respirator to an unlabeled nitrogen line (only the shut-off valve was labeled) used by the refinery for purging confined spaces. Plant nitrogen and airlines were identical, and both had couplings compatible with the coupler on the respirator. The crew member was killed.

Source: osha.gov

Fire when opening a level gauge connected to a molten sulphur tank

In a molten sulphur tank in a refinery, receiving of molten sulphur was stopped as the level gauge was not working. When instrument personnel opened the top side of the level gauge, a fire started as there was pyrophoric iron sulphide inside the level gauge top chamber. The H2S inside the tank also caught fire.

Are you training your operators on the hazards of storing molten sulphur?

Is your relief valve sizing method truly rigorous?

Is your relief valve sizing method truly rigorous?

Pressure relief with rupture discs

Pressure relief with rupture discs

Protecting against high pressure rupture (TIA)

Protecting against high pressure rupture (TIA)

Protect control valves when production slows

Protect control valves when production slows

Mitigating corrosion with a digital twin

Mitigating corrosion with a digital twin

When replacement in-kind gives performance that isn’t: a vibration case study

When replacement in-kind gives performance that isn’t: a vibration case study

Process safety time for fired heaters

Process safety time for fired heaters

Safe removal of polymeric deposits

Safe removal of polymeric deposits

PIGS ARE DANGEROUS!

 https://www.bsee.gov/sites/bsee.gov/files/safety-alerts//safety-alert-356-pipeline-pigs-inadvertently-launched-in-close-proximity-of-personnel-into-gulf.pdf

TEG SOAKED INSULATION FIRE INCIDENT

A fire on an offshore installation has highlighted the risk of low temperature spontaneous combustion from TEG soaked insulation. An investigation has shown that spontaneous combustion of TEG soaked into fibrous materials can occur at relatively low temperatures (70oC). Therefore, specific precautions are required for stripping and disposal, to avoid unexpected ignition and fire.

The incident occurred on the process deck and involved removal of the aluminium cladding and TEG soaked insulation (Kaowool Ceramic) from dehydration system pipework following a small leak of hot TEG from a flange. The materials were temporarily stored, with rags used to mop up excess TEG from the deck, in a plastic sack. Spontaneous combustion subsequently caused a fire, which consumed the sack and contents.

The TEG soaked insulation was at, or near, the pipework temperature when it was placed in the plastic sack. The process of stripping the insulation allowed air to be absorbed into the insulation. In addition, dry hot insulation could have come into contact with TEG soaked insulation after being removed from the pipework.

As the insulation cooled it was possible for an oxidation process to have begun in the centre of the waste in the plastic sack, which eventually gave rise to spontaneous ignition and combustion.

This incident is an example of a well-recognised phenomenon more often observed in oil soaked rags in workshops and insulation soaked in mineral oil. It is less common in relation to TEG but can occur in the following circumstances: For spontaneous combustion to occur, TEG must be absorbed into an insulating material which has sufficient void spaces for air to be absorbed. The temperature will rise if the temperature of the insulation is relatively high and the volume sufficient to allow heat generated by an oxidation process at its centre to be retained. The larger the volume of the insulation, the greater the amount of heat retained and the lower the temperature at which spontaneous combustion of the TEG will begin. High temperatures can develop that could lead to a fire. If the bulk of TEG soaked insulation is large enough, spontaneous combustion could occur even if the insulation starts from cold. However, the time taken before the initiation of the rapid heating process would be much longer. TEG soaked rags are much less reactive than insulation, but could still present a hazard. TEG dehydration systems can run at temperatures up to 200oC and pipework is often insulated with fibrous rock wool type material. This material has a structure suited to the absorption of air into the void spaces. In normal circumstances the insulation will be clad with aluminium plate, which holds the insulation in a compressed state and prevents the ingress of air. When cladding is removed and the insulation stripped from the pipework, air will be absorbed into the insulation. If the TEG and insulation are hot from the process pipework and collected in bulk, the conditions within the stripped material can be susceptible to spontaneous combustion.

SOURCE:IOGP

Deficiencies in process piping cause gas release

https://www.bsee.gov/sites/bsee.gov/files/safety-alerts//bsee-safety-alert-402-deficiencies-in-process-piping-cause-gas-release-incidents.pdf

INCIDENT DUE TO VALVE BUSH LEAK

 https://www.ppsa.org/assets/SaftyAlerts/hazard_alert___valve_failure.pdf

INCIDENT DUE TO BLOCKING OF ISOLATION VALVE

 In 2008, facility workers in the US closed an isolation valve between the heat exchanger shell and a relief valve to replace a burst rupture disk. Maintenance workers replaced the rupture disk on the day, however, they forgot to reopen the isolation valve. The next day, other facility workers closed a block valve to isolate the pressure control valve from the heat exchange so that they could connect a steam line to the process line to clean the piping. The steam flowed through the heat exchanger tubes, heated the liquid in the exchanger shell, and increased the pressure in the shell. The closed isolation and block valves prevented the increasing pressure from safely venting through either the pressure control valve or the rupture disk and relief valve. The pressure in the heat exchanger shell increased until it violently ruptured.

How To avoid PRV performance problems

 https://www.valvemagazine.com/magazine/sections/features/4427-how-to-avoid-prv-performance-problems.html

MY ARTICLE IN CEP ISSUE JANUARY 2021

My fourth article "Understand Process Hazards to Safely manage Change" has been published in the January 2021 issue of the CEP magazine of the American Institute of Chemical Engineers. Read it after logging in in this link https://www.aiche.org/publications/cep

You have to be a member of AIChE to read it.

WHEN ISOLATIONS GO WRONG

 https://www.hse.gov.uk/chemicals/workshop/safe-isolation-10/go-wrong.pdf

Tank explosion due to a chemical reaction

The accident occurred when nitric acid delivered to a factory by a tank truck was unloaded into the wrong tank. The tank exploded due to a chemical reaction within the tank.Around 5:30 in the afternoon on the day of the accident, the driver of the tank truck carrying nitric acid arrived at the factory, handed over a delivery slip to the employee inc harge of accepting deliveries, and connected the hose of the tank truck to the flange(for unloading).As this was the first time for the driver to make deliveries to this factory, his co-worker who has delivered to this factory before told him that the flange for nitric acid was the second from the left. However, as the second flange from the left was made of vinyl chloride and the driver did not think that this could be the pipe for nitric acid, the driver connected the hose to the second flange from the right, which was made of stainless steel.After the connection of the hose, the employee in charge of accepting deliveries opened the electromagnetic valve, and the driver started the discharge. As the liquid surface of the nitric acid tank did not rise, however, the driver checked the label of the tank and found that he was unloading nitric acid into the tank for triethanolamine.The driver informed the employee in charge of accepting deliveries of the mistake,connected the hose to the correct flange for the nitric acid tank, and completed the unloading in about 20 minutes. When the driver was going out from the front gate, he noticed white smoke being emitted from the tank. Around 6:25 in the afternoon, the sub-tank and main tank for triethanolamine that were wrongly charged exploded,releasing a chemical spill in the area.No injuries or fatalities were caused by this accident.

Causes

The following can be considered as the causes of this accident.The hose of the truck delivering nitric acid was mistakenly connected to the pipe for the wrong chemical. The contact and coordination procedures for chemical delivery work were insufficient.Safety and health education for workers was insufficient.

Source: tamu.edu

HAPPY NEW YEAR!

 A VERY HAPPY AND SAFE NEW YEAR TO ALL MY SUBSCRIBERS! KEEP SAFE!

STARTING MY 11TH YEAR OF BLOGGING!

Dear Readers,

Thank you for being with me for the past 10 years since I started my blog. 

1800 posts, 325000 views, about 800 incidents and many of my readers spreading the information from the posts through process safety one point lessons within their own organizations...I am still far from satisfied. My mission in life has been "Preventing another Bhopal" and let us not rest till we have achieved it. How can you help? By the following steps:

1. Never be silent when you see something going wrong - it could be a decision that is not in the interest of process safety - speak up!
2. Share past incidents (internal incidents and external incidents) and their root causes, with all your colleagues - we see the same old incidents repeating
3.  As an engineer, be ethical when taking decisions and do not take decisions because they please the boss
4. Update your technical knowledge continuously
5. Do not be carried away by all the technologies that vendors try to sell you. Thoroughly study them and employ only those technologies that are useful to you. Don't get carried away by Jargon.
6. Wear your engineering hat always, even when you go up the management ladder.
7. Be aware of normalization of deviations around you. Report them and determine the root causes. You work in a chemical plant. You and your colleagues should not have the misfortune of seeing people die before your eyes because of an incident....

I end by quoting Robert Frost, "The woods are lovely, dark and deep, but I have miles to go before I sleep"

The working of a flame arrester

 

Process safety beacon on flame arrestor

 https://www.aiche.org/sites/default/files/cep/20160420.pdf

Can a flame arrester element be made of a non metallic element?

Flame arresters are often provided on vent lines in atmospheric storage tanks storing flammable materials. The principle of operation is by cooling the flame and extinguishing it before it reached the inside of the tank. As the flame travels through the element, it is exposed to a large area of the element, which can be folded meshes etc. But do you know that the element inside does not necessarily have to be metal? The flame arrester element itself experiences very little warming, because it is subjected to a high temperature for a very short time. Heat transfer is initially due to convection/diffusion and then later due to conduction after flame has been extinguished. Hence non metallic elements like PTFE can be used to avoid plugging. See one vendors catalogue here https://www.protego.com/products/detail/FA-I-PTFE.html

Note: This is for information only.

CSB releases airgas safety spotlight

 https://www.csb.gov/csb-releases-airgas-safety-spotlight-/

INCIDENT DUE TO BLOCKING OF ISOLATION VALVE

 In 2008, facility workers in the US closed an isolation valve between the heat exchanger shell and a relief valve to replace a burst rupture disk. Maintenance workers replaced the rupture disk on the day, however, they forgot to reopen the isolation valve. The next day, other facility workers closed a block valve to isolate the pressure control valve from the heat exchange so that they could connect a steam line to the process line to clean the piping. The steam flowed through the heat exchanger tubes, heated the liquid in the exchanger shell, and increased the pressure in the shell. The closed isolation and block valves prevented the increasing pressure from safely venting through either the pressure control valve or the rupture disk and relief valve. The pressure in the heat exchanger shell increased until it violently ruptured.

CONFINED SPACE FATALITY

https://www.gov.uk/maib-reports/entry-to-enclosed-space-on-fishing-vessel-sunbeam-with-loss-of-1-life

Do not depend on remotely operated valves for isolation for maintenance work

The two incidents below highlight the fact that you should not depend on rmotely operated valves for isolation during maintenance activities. ROV's are meant for use only during emergencies to prevent a major loss of primary containment:

1. A bolted joint was opened for maintenance on a pump but reliance for isolation was placed on a remotely actuated valve. The valve was inadvertently opened either from the control room or from the motor control centre resulting in a major release of flammable gas, with subsequent explosion.
   
2. A fire occurred during the removal of a blind. The blind was located downstream of an air actuated valve which was inadvertently opened during blind removal. This released flammable liquid, resulting in a large fire and multiple fatalities.
   

On the 36th anniversary of the Bhopal Gas Disaster

Are we better off in Process Safety Management than what we were when the Bhopal disaster occurred in 1984? I would answer this by saying that those who wanted to improve have certainly done so, with the help of various process safety initiatives by industry. But we continue to hear about many incidents every year that mar the image of the chemical industry. Based on my 41 years of experience (out of which the first 20 years were in operating plants and the next 21 years were in process safety consulting), I think the answer boils down to this basic fact. Some one said " The whole World moves on Vitamin M (Money)". After an incident, there is always a big reaction, but after some time, it becomes business as usual in some companies, and that's when another incident occurs. Can technology prevent incidents? The answer is yes, to a certain degree. But ultimately, it is decisions taken by the humans (and I am not talking about the human sitting in the control room) that cause an incident to occur. In Bhopal gas disaster too, decisions taken far away from the plant had an impact on the plant. 

Mahatma Gandhi had once said "The Earth has enough for everyone's need, but not for everyone's greed". Your views, please....

Nitrogen hose burst due to overpressure

A release of ammonia occurred from a chemical plant when a hose burst following maintenance to an ammonia filter. The release of ammonia was detected by operators due to ammonia alarms and a high flow of ammonia to the plant. The site emergency siren was activated to alert people of the incident and operators isolated the supply of ammonia to the plant. Operators donned personal protective equipment and doused the leak with water in order to gain access to the area to isolate the leak.

Cause

Ammonia filters were used to remove contaminants from the liquid ammonia, prior to it being processed in the plant. An essential step in the maintenance of filters is a nitrogen purge of the system. After purging occurs, the filter is changed, resealed and the nitrogen hose disconnected. The relevant valves are then opened to recommission the system with ammonia. In this instance, the nitrogen hose remained connected to the filter and drain valves were left open allowing the hose to become pressurised with liquid ammonia. While the hose was suitable for the pressures normally experienced under service with nitrogen, the hose was not suitable for the much higher pressures of liquid ammonia and as a result the hose burst in two places.

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

Heat exchanger tube leak causes ammonia gasket failure

A mixture of process gases was released to the atmosphere through a failed gasket during the start-up of a chemical plant. Operators had just completed the start-up when they heard a large sound and received alarms from ammonia detectors.The plant was shutdown, however the plume released travelled off-site necessitating the evacuation into refuges of a small number of workers on a neighbouring site. No-one was injured as a result of the release.

An investigation showed that the gasket failed as a result of a hole in a boiler tube which had allowed water to pass from the boiler side into the process side. The temperature generated during start-up caused the pooled water to rapidly boil leading to a surge in pressure which resulted in the failure of the gasket. Non-destructive testing of the boiler tubes showed gouge-type corrosion believed to have been caused by flow distribution problems in the boiler. This resulted in excessive metal temperature, which led to corrosion of the tube.

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

Accident due to a temporary connection

The alkylation unit was going into shut down. Two contractors were fixing a copper tube to a T-piece of a drain. During the work they turned the T-piece over 90°. Due to this fact a valve on the T-piece was accidentally opened and an amount of hydrogen fluoride (HF) was released. One of the contractors was very seri-ously injured. His eyes, nose and mouth were burned and he inhaled HF fumes, which caused internal injuries to them. The second person only had small injuries around his mouth.CausesBecause the alkylation unit was shut down, the biggest equip-ment was already emptied and the installation was cleaned with nitrogen. Then it was decided to drain the unit to remove all flu-ids left. The drain consisted of two valves and a blind flange. The blind flange was removed and replaced by a T-piece consisting of a manometer and a small valve. The T-piece was mounted in a horizontal way. A permit was written for two contractors to add a copper tube to the small valve on the T-piece. Because it was not easy to work with the T-piece mounted horizontally they decided to rotate the T-piece. While rotating the piece, the handle of the small valve touched a pipeline which opened the valve and 360ml HF was released. 

Important findings

The T-piece on the drain was a temporary piece only installed for the shutdown. There was no standard in the company to which temporary pieces had to comply. The T-piece used screw thread which made it possible to turn the T-piece. The accident showed that a standard for temporary pieces must be drawn up.In the company it was seen as normal that the manual valves in the line on which the T-piece was fitted had a small internal leak. So in the work permit protective clothing should have been specified for working on this line since they should have antici-pated that HF would build up between the fixed (leaking) valves and the quarter turn valve on the temporary T-piece. A quarter turn valve is easily manipulated accidentally, certainly while doing mechanical work in the immediate vicinity.

Source: European commission

What will go wrong will go wrong!

 On July 14, maintenance works were completed in a soy beans extraction plant. Following the inspection by the plant operator, the start-up of the facility was initiated at 21:30. Steam was admitted to the toaster and to the jackets of hexane inlet pipes to heat-up the toasters and the extractor to the proper operating temperatures.
At about 21:45 the toasters reached their operating temperature and admittance of flakes commenced through the inlet screw conveyor. After that the night shift took over. They had some difficulties controlling the process temperature (dropped), and therefore increased heat supply to the toaster. About the same time, the sound of the safety flap valve lifting was heard, and it released hexane and steam into the extractor building, where the smell of hexane was detected by the operators. The hexane concentration in the extraction building finally reached a level which forced the staff out of the extractor building. A bus driver passing the plant detected the vapours and informed the Traffic Control Centre that “airplane fuel was spilled on the road”. With this information, at their arrival, firefighters took a precautionary approach and parked the fire engine at a safe distance, walking the last hundreds of meters. The plant manager arrived at the scene and discussed with the incident commander how to stop the outflow of hexane vapour, and deciding ultimately to cutoff the power supply to the extraction plant. The manager there after asked the power control unit to turn off two transformers under the load. (There was also one unloaded). Due to inherent risk of possible sparks he rejected stopping the electrically loaded transformers and instead, disconnected the third, unloaded transformer. Approximately 30 seconds later, a sudden fire was observed outside the plant which was followed by a violent explosion. The explosion injured 27 persons, among 7 emergency responders and 20 staff members of the plant. The extraction plant was destroyed by the explosion and was notre-established. The explosion was probably initiated by the attempt to disconnect one of the three supply lines to the extraction plant.

Important findings
• Apparently, the smell of hexane which was detected by the operators was not an abnormal occurrence during the start-up.
• The site also stored large amounts of chlorine and hydrogen in the facility. Therefore, it was urgent that the incident commander and the plant manager work quickly together to prevent the explosion.
• The investigation revealed that no emergency shut-down procedure existed for the extraction plant.

Lessons learned
• Due to the conflict of following orders, the question arises who is in charge to give orders relating to operation of the plant, is it the incident commander or the operator? Who makes final decisions to shut down the electricity? Roles should be identified during normal operation when the operator drafts the internal emergency plan. The fire brigade should have visits to the plant to become familiar with the operation and discuss the emergency procedures with the plant manager and the control room operators.
• Emergency shut-down operations are crucial when operating a plant with the hazards of release of toxic materials or fire/explosion and that these protocols are followed.
• No alarm was activated to inform the public about the hexane release. Information to the public and activating the alarm is one of the most important emergency protocol in case the consequences might affect the nearby population.

Source: European commission

Fire due to welding operation

A fire started at the manhole of an inspection pit for underground pipes of a petroleum storage depot during a welding operation as part of maintenance work on the piping supplying a tank. The underground pipes were feeding eleven tanks in different conditions. At 11:15 a.m., a leak of premium-grade gasoline occurred, followed by a sudden flash. Site technicians attempted to extinguish the ensuing pool fire. The operator activated the internal emergency plan, issued the order to close all motorised valves and called for assistance from petroleum industry partners. At 14.00, emergency responders were still unsuccessful in suffocating the fire with sand. At 15:20 an explosion occurred which was caused by two acetylene cylinders used in the welding operation. Fed by an unknown source, the fire continued to rage for several hours despite firefighting interventions. Eventually, the foot valve on the adjacent gasoline tank was found open by the firefighters. After its closure, the fire receded Intervention efforts were substantial and the toll quite heavy; 15 firemen were burned during the accident: 2 of them were badly hurt, 5 seriously and 8 slightly. Apparently, the firemen suffered burn injuries due to a gust of wind and for the cylinders' explosion. The entry valve of the adjacent tank was left open for an unknown reason.

Important findings
• According to the site director, the piping should have been submerged in water during the onsite works and therefore was omitted from the valve closure checklist and control diagram.

Firefighters encountered myriad difficulties, in particular:
• The fire route to the tank was submerged under a layer of burning hydrocarbons;
• Fire water pipes burst under the weight of vehicles evacuating the zone;
• Lack of information about the source of the fire.

Lessons Learned
• The accident scenario was not included in the site’s risk assessment study. Fires initiated from welding operations are abundant in the literature.  A hazard assessment of tank maintenance operations should examine all possible ignition scenarios (what if?) associated with hot work.
• In order to prevent subsequent fires or explosions to occur, ignition sources, such as the acetylene cylinders should be removed from the area of emergency operation.
• Operators should provide accurate information on location of safety instrumentation to the emergency responders as soon as possible, especially if such devices can contribute to the fire or explosion.

Source: European commission

HCL leak incident

In a sulphur dichloride (SCl2) distillation facility in a chemical plant, a spillage of SCl2 occurred in the retention area for a distillation column in the final stages of distillation, after a leak from a recirculating pump. The SCl2 hydrolysed upon contact with ambient humidity, causing an intensive emission of hydrogen chloride (HCl), which was not detected by the HCl gas detector of the column. But a safety detector installed in the unit gives the alarm at 13:12. The controller placed the unit in safety shut down and then triggered locally the audible and visual alarm while alarm messages appear on the control screens in the control room. The internal emergency plan was activated and the 35 employees were evacuated. The internal fire team, supported by 40 external firefighters, equipped themselves with breathing apparatus and plugged the leak. The cloud of HCl was overcome using 4 lateral fire hose lines. The 120 m³ of water used is collected in a retention pond for reuse in production. The internal emergency plan is terminated at 16:15 pm. The next day a specialized company pumped 800 liters (1,200 kg) of sulfur dichloride from the retention basin into a storage tank. The HCl release remained confined inside the building. 

Source:European commission

Lightning strike in an ethanol tank in distillery

In a distillery, a 5,000-m³ tank containing 1,000 m³ of ethanol at 96% concentration exploded when lightning struck and then ignited. The raised roof fell into the reservoir, which remained intact. However, the tank foot valve cracked upon impact. An emulsifier delivered 2 hours later enabled preventing the fire from spreading to the 1,000-m² retention basin. The blaze was extinguished in 3 hours and the fire-fighters for over 5 hours cooled 3 adjacent 2,500 m³-tanks exposed to the intense heat. During the emergency response, 23,000 litres of emulsifiers stored onsite and a total of 7,000 m³ of water (including cooling water) were used. The loss was valued at 30 million francs (including 2.5 million of alcohol destroyed and 3 million of emulsifier). The extinction water (1,500 m³) collected in the retention basins would be diluted in a lagoon. An outside organization was called to verify the electrical installations of the storage zone. 

An internal response plan drill conducted 2 months earlier, based on a comparable scenario involving one of the tanks involved in the accident, served to facilitate the actual intervention. It had been recommended to install flame arrestors on the vents and the breathing valves on the tanks following a lightning risk evaluation study conducted 18 months prior to the event.

Source: European commission

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