December 28, 2021

Explosion due to hydrocarbon being drawn into boiler firebox

A leak in a hydrocarbon refrigerant system formed a vapor cloud that was drawn into the inlet of a steam boiler. The increased fuel to the boiler caused rapidly rising pressure within a steam drum. The rapidly rising pressure exceeded the capacity of the boiler’s safety valve and the steam drum ruptured. The boiler rupture was close enough to the gas leak to ignite the vapor cloud and produce an explosion due the confined nature of the gas lea  and an ensuing fireball. The fire took eight hours to extinguish. The explosions and fire destroyed a portion to the LNG plant and caused 27 deaths, and injury to 72 more.

December 24, 2021

LNG leak causes sewer explosion

 LNG leak from open run-down line during a pipe modification project. LNG entered an underground
concrete storm sewer system and underwent a rapid vapor expansion that overpressured and ruptured
the sewer pipes. Storm sewer system substantially damaged.

December 2, 2021

ANOTHER ANNIVERSARY OF BHOPAL.....National Process Safety Week on anniversary of Bhopal disaster December 3rd

Tonight is the 37th anniversary of the Bhopal gas disaster. We still do not seem to learn from Bhopal. The same mistakes that occurred at Bhopal keep recurring in various incidents around the World. Production pressures along with cost cutting measures take a toll on process safety. Just like the National safety week in march, I mooted the idea of having a National Process Safety Week every year on the anniversary of Bhopal for all chemical industries in India. During this week, the root causes of the Bhopal disaster and process incidents in individual organisations can be discussed with all  employees including top management. The root causes are again given below: They are still relevant today:

1. Do not cut costs without looking at the effects on process safety
2. Maintain all your layers of defense including asset integrity
3. Continually ensure that competency of personnel operating and maintaining plants are updated and current
4. Be prepared for the worst case scenario.
5. Understand the risks and measures to eliminate / reduce or control them
6. Learn from your past incidents. Those who do not learn are condemned to repeat the incidents.
7. Pay heed to your process safety management system audit reports

 I am again attaching the link of some pictures of the victims of Bhopal, lest we forget..........

" Mothers didn't know their children had died, children didn't know their mothers had died, and men didn't know their whole families had died" - Ahmed Khan, Bhopal resident on the Bhopal disaster

November 30, 2021

How to Avoid Common Genset Room Design Mistakes

How to Avoid Common Genset Room Design Mistakes: The room and building that a power generating set will be located in must comply with all genset room design requirements to ensure reliable operation.

November 26, 2021

How to Clean Natural Gas Piping with Gas Blows

How to Clean Natural Gas Piping with Gas Blows: Before new fuel gas piping can be connected to a combustion turbine (CT), it must be cleaned by “decompression” gas blows. Here's how to do it.

November 22, 2021

New Lockout-Tagout Program Improves Safety

New Lockout-Tagout Program Improves Safety: To improve overall employee safety across plants and facilities, switch from a tagout-based safety program to a lockout-tagout (LOTO) program.

November 18, 2021

Understanding the Dangers of Hydrogen Sulfide Gas

Understanding the Dangers of Hydrogen Sulfide Gas: Hydrogen sulfide (H2S) gas is produced as a result of the microbial breakdown of organic materials in the absence of oxygen. It can be found in tanks,

November 14, 2021

Cultivating a Safety Culture Amid Constant Change

Cultivating a Safety Culture Amid Constant Change: Developing a power plant safety culture takes time and constant effort, but the payoff is priceless, safety leaders at three major power companies said

November 10, 2021

How to Conduct Steam Blowing Procedures with Remote Personnel

How to Conduct Steam Blowing Procedures with Remote Personnel: Many power projects have been disrupted due to COVID-19. However, managers at Larsen & Toubro Ltd. found a way to complete steam blow requirements in spite of the pandemic, using secure internet

November 6, 2021

November 2, 2021

Principles-Based Operations: A Military-Proven Method Part I

Principles-Based Operations: A Military-Proven Method Part I: Many organizations have begun applying operational principles used with great success in the millitary. The foundation for postive outcomes is integrity.

October 28, 2021

Employee Location Monitoring in a Post-Pandemic World

Employee Location Monitoring in a Post-Pandemic World: The COVID-19 pandemic has unearthed a number of challenges for power plant managers. However, technology exists to keep workers safe. Through the use of Location Anchors and WirelessHART infrastructure

October 24, 2021

Improving Asset Inspections with Drones and AI

Improving Asset Inspections with Drones and AI: The U.S. bulk electric system has more than 360,000 miles of transmission lines, which means power companies have a lot to inspect. Drones and AI can help.

October 20, 2021

Flame-Resistant Clothing: Everything You Need to Know

Flame-Resistant Clothing: Everything You Need to Know: Flame-resistant (FR) garments are an important safety item for workers in the power industry. However, protection varies based on the arc rating of the clothing. Wearers must understand how the FR clothing

October 16, 2021

Protecting Battery Energy Storage Systems from Fire and Explosion Hazards

Protecting Battery Energy Storage Systems from Fire and Explosion Hazards: There are serious risks associated with lithium-ion battery energy storage systems. Thermal runaway can release toxic and explosive gases, and the problem can spread from one malfunctioning cell to neighboring cells, resulting in catastrophe.

October 12, 2021

Preventing and Mitigating Oil Fires in Power Plants

Preventing and Mitigating Oil Fires in Power Plants: It has been said that a picture is worth a thousand words. However, photos of the conflagrations that have resulted from ignition of minor lube oil leaks on a typical steam turbine room floor will leave you speechless. Full-scale physical simulations of oil fires by the insurance company FM Global leave no doubt that power plant fire prevention and mitigation is a judicious blend of art and science.

October 8, 2021

Does your safety observation system create victims, villains?

Does your safety observation system create victims, villains?: Chances are you have a behavior-based safety (BBS) process in place for all of your projects. And the reason you have that BBS process to begin with is to reduce accidents.

October 4, 2021

FATALITY DUE TO EXPLOSION IN NITRIC ACID TANK

 A small steel process tank was filled with multiple metal baskets of tantalum capacitors cooked overnight in hot nitric acid. The hot nitric acid was used to remove some of the epoxy resin encapsulant from a tantalum anode. The nitric acid was drained each morning after the capacitors were cooked. The baskets of cooked capacitors were removed and rinsed in water. Mostly tantalum anodes remained. Employee #1 was killed and five other employees were seriously injured as a residue, containing picric acid, exploded, when Employee #1 placed a basket back into the drained tank, presumably to remove more encapsulant. Picric acid (trinitrophenol), and possibly other unstable nitrated compounds, formed in a nitration reaction between nitric acid and the bisphenol moiety of the epoxy resin. These nitrated compounds precipitated out of the nitric acid solution. Over time, as the spent nitric acid was drained from the tank after each batch, the precipitated nitrated compounds would accumulate on the inside surface of the tank. The spent nitric acid was typically used for multiple batches further concentrating unstable nitrated compounds on the tank's surface. Placement of the basket was likely the source of ignition. The explosion was estimated to be of a magnitude similar to an explosion involving more than 5 pounds of trinitrotoluene. The five seriously injured employees were treated for burns and bruises at a local hospital. 

 Source:OSHA.gov

September 30, 2021

September 6, 2021

Employee Inhales Toxic Gas, Later Dies

At 6:15 a.m. on May 22, 2020, an employee and a coworker were in the process of transferring chemicals from totes on a delivery truck into tanks inside the facility. The employee was responsible for hooking up the hose to the fill line on the building and monitoring the transfer from inside the facility. The coworker was responsible for hooking up the hose to the pump and tote inside the truck. The employee accidentally hooked up the bleach hose to the fluoride fill line, causing a reaction when the chemicals mixed. A toxic gas, presumably chlorine, was given off and the employee inhaled the gas. The employee was hospitalized from t he inhalation of the toxic gas, and died from the injury.  

Source:OSHA.gov

September 2, 2021

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 pun gent 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

August 28, 2021

Steam cap failure incident

 At 8:12 a.m. on November 13, 2020, Employee #1 and a coworker, employed by an HV AC company, were repairing a steam piping system leak in the mechanical room of a medical care campus building. The employees did not utilize a lockout and/or tagout device. Following the repair, as the steam line was being re-energized, a threaded drip cap at the bottom of the vertical steam pipe riser apparently failed. The room immediately filled with pressurized steam. The interior door was in the closed position, and the employees were unable to exit the room. Employee #1 was killed. 

Source:Osha.gov

August 16, 2021

 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

August 12, 2021

 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

August 8, 2021

 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
 
 

August 4, 2021

Role of fired heater safety systems

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

July 30, 2021

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

July 26, 2021

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/

July 22, 2021

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.

July 18, 2021

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

July 14, 2021

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

July 11, 2021

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

July 7, 2021

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

July 3, 2021

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

June 29, 2021

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

June 25, 2021

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/

June 22, 2021

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

June 18, 2021

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

June 14, 2021

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

June 10, 2021

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

June 7, 2021

SUBSCRIPTION TO MY POSTS BY EMAIL - CHANGE - LAST WARNING

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June 6, 2021

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

June 2, 2021

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

May 29, 2021

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.

May 17, 2021

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

May 13, 2021

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

May 5, 2021

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

May 1, 2021

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

April 27, 2021

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

April 23, 2021

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

April 19, 2021

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

April 15, 2021

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

April 11, 2021

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

March 30, 2021

CONDENSATE INDUCED WATER HAMMER INCIDENT

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

March 27, 2021

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

March 26, 2021

March 22, 2021

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”

March 18, 2021

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

March 14, 2021

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

March 10, 2021

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

March 5, 2021

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

March 1, 2021

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?


January 25, 2021

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

January 13, 2021

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.

January 9, 2021

January 2, 2021

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

January 1, 2021