January 4, 2020

My article on Flare Systems published in Chemical Engineering progress of AIChE

When I started my career 40 years ago, I used to be an avid reader (and still continue to be) of Chemical Engineering Progress of the AIChE. The articles helped me throughout my career. I am happy to say that my third article
"Manage Change to Flare Systems" has been published in the January 2020 issue of CEP. Please see it in this link

January 3, 2020

Glycols can burn

Incident #1
An atmospheric tank overfilled with glycol. The glycol came in contact with a nearby burner, igniting and causing a fire.
Incdient #2
Employees #1 and #2 were installing a platform on top of a storage tank containing ethylene glycol. While the tank was receiving an ethylene glycol mixture from the process line, Employee #1 began to weld a clip on the tank. Shortly after striking the arc, the top of the tank blew open and the contents ignited. Employee #1 received burns, lacerations, and fractures which later resulted in his death and Employee #2 received minor cuts and bruises.  Source: osha.gov

Have you checked the MSDS of the glycols you are using? Often operators think that glycol is not flammable.

December 31, 2019

2020 - Happy New Year!

Wishing my readers and their families a very happy 2020! Lets all work together to make 2020 safer than the previous years and avoid LOPC incidents!
Thank you for taking the readership of my blog to above 300,000 views.

Are your pressure relief valves sized corretcly?

Employee #1, the basement operator at a powerhouse, was purging the liquid residue from the betene entrainment tank to the #16 boiler. Water and steam inadvertently got into the knockout pot, and materials that react to water, such as, but not limited to, acetic anhydride and diketene were in the tank. A reaction occurred, releasing flammable and hazardous materials into the atmosphere through a safety relief valve. The pressure relief device was only sized for an external fire, not a chemical reaction. As a result, the safety relief valves could not withstand the reaction. The overpressurization caused the steel pot to fail and explode. Employee #1 was killed.
Source:osha.gov

December 26, 2019

Another incident where "tryout" was not done

On July 23, 2009, Employee #1 and a coworker, both contract employees specializing in preparation of refinery equipment for entry, were installing blinds in piping preparatory to confined space entry for inspection and maintenance. The pressure vessel was removed from service, cleaned, flushed and drained. The column was under a nitrogen purge of approximately one psi to facilitate the draining. Employee #1 and the coworker encountered pressurized steam at the top of the vessel while installing the blinds. At the bottom of the vessel, Employee #1 and the coworker began to loosen flange bolts when they encountered hot water leaking from the 16 bolt, 300 lb flange. As Employee #1 loosened one of the last two bolts, the flange opened and Employee #1 was sprayed with 197 degree F hot oily water. Employee #1 sustained first and second degree burns to the neck, arms, shoulder and upper back. Employee #1 was hospitalized. It was determined the Controlling Employer did not verify that the equipment had been deenergized.
Source: osha.gov

December 25, 2019

How do you try out hazardous energy systems?

Two maintenance men at an electric power generation plant removed a check valve cover from a steam system. The section of the steam line was isolated and tagged, but it could not be vented or drained first. The section was only partially depressurized when the cover was loosened. When the employees removed all fasteners holding the cover in place, it blew off, and the steam line sprayed the two employees with steam and hot water. The employees were wearing safety glasses and work gloves, but were not using any other shielding or protective clothing. The employees received second degree burns over 20 percent of their bodies.
Source: osha.gov

December 21, 2019

Sight glass rupture incident

On April 9, 1986, Employees #1 and #2 were tightening a manhole cover plate on a 1,000 gallon capacity steam jacketed pressure vessel. The vessel was in service, agitating and heating a wax emulsion product by a pressure emulsion process when a 4 in. diameter, 3/4 in. thick sight glass ruptured. It threw out an explosion-proof light that was mounted over the sight glass and broke a 1 in. diameter steam line. Employee #1 was killed and Employee #2 was burned by steam and the hot wax emulsion product. The pressure relief valve on the 75 psi vessel was rated at 150 psi and was not operational. No maintenance or vessel inspection documentation could be located.
Source:osha.gov

December 17, 2019

Manage changes safely!

A storage tank containing 93 percent sulfuric acid ruptured and its contents were released to the environment. Employees responded to the acid spill by constructing a dike, using gravel, lime and sand. Forklift drivers removed galvanized poles from the spill. The acid reacted with the lime, and released a white "cloud" with irritating properties which enveloped many of the responding employees. The employer called the Fire Department HAZMAT Team who responded to the scene. When the HAZMAT Team arrived employees were ordered to cease activities. This facility used sulfuric acid in the galvanizing process. The horizontal tank that ruptured had a storage capacity of 3,770 gallons of sulfuric acid and was located outside the facility in containment. It was used to replenish the sulfuric acid dip tanks. It was not designed and manufactured as a pressure vessel. The tank ruptured during the transfer of acid from the storage tank to dip tank(s) located inside the plant. Acid was transferred from the storage tank to dip tank(s) by pressurizing the storage tank with compressed plant air. The compressed plant air line went through an in-line air dryer which had not been maintained according to the manufacturer's instructions. The compressed air pressure to the storage tank was normally reduced from 120 psig by a regulator down to 30 psig. However, engineering design criteria specified that the regulator be set at 10-15 psig. After the accident, the regulator was found to be set at 90 psig. In addition, the regulator had recently been replaced and did not meet the engineering design specifications of the original regulator. An accident investigation concluded that the tank ruptured due to over-pressurization within the tank. After their exposure, employees reported burning faces, throats, headaches, and chest pain. Many of the employees coughed and choked, and had difficulty in breathing.
Source:osha.gov

December 14, 2019

Inadvertent mixing of chemicals

On May 23, 1998, Employee #1 mixed a cobalt solution and Methyl Ethyl Ketone Peroxide (MEKP) together when the solution exploded and fatally burned Employee #1. Employee #1 was believed to be in the process of pouring excess liquids, which accumulated in the top measuring cup, back into the original container. Employee #1 inadvertently poured the cobalt solution into the MEKP bottle. These chemicals are violently incompatible. The label on the cobalt solution was illegible.
Source: osha.gov

December 11, 2019

Be careful of peroxides!

On August 28, 1994, at 9:10 p.m., Employees #1 and #2 were adding hydrogen peroxide to a tank of wastewater containing a dilute solution of cyanide and caustics. The hydrogen peroxide was being added by gravity from the floor above. The hydrogen peroxide tank began to "bump" (bubble from escaping gas), so the employees opened the valve more fully to increase hydrogen peroxide addition speed when an explosion occurred which totally destroyed the peroxide tank. Employee #1 was treated for chemical and thermal burns on his hands and released. Employee #2 was admitted to Lawrence Memorial Hospital in New London, CT, with multiple burns and serious eye damage. On August 30, the employee's eye recovery prognosis was "good." A later prognosis was "excellent." The ophthalmologist expects 100 percent recovery in both eyes.

December 10, 2019

How well trained are your operators on emegrency reponse?

Employees #1 and #5 through #7 were near the chlorine unloading area at a bleach plant when the gasket of a recently-installed vaporizer failed, releasing between 500 and 700 gallons of liquid chlorine. When Employees #1 and #7 went to investigate the extent and location of the leak, they found an overwhelming concentration of the chemical. They were not using SCBAs, nor was Employee #6, who used the wrong escape route. Employee #5, the bleach plant operator, attempted to find and assist Employee #6. Employees #2 through #4 attempted to shut down the vaporizer system but they did not know the location of the one critical shut-off valve, and the key person was not immediately available to help. Employees #1 through #7 suffered chemical burns from inhaling the chlorine fumes; all were hospitalized except for Employee #2.
Source:osha.gov

December 8, 2019

Mechanical seal failure incident

On April 6, 1994, a unit operator was conducting rounds of the coker unit when he observed a leak coming from the mechanical seal of the heavy gas oil pump of coker unit #1. The operator decided to seek assistance; the head unit operator and six or seven unit operators responded. The operators placed water and steam on the leak to suppress the vapor from the seal. The head unit operator decided to shut down the pump and transfer the product to the secondary pump. As the operator shut down the primary pump, the mechanical seal blew, causing a vapor cloud to generate from the seal. The operators continued to put steam and water on the seal and isolated the pump from the pipe line. The remaining product in the pipe line leading to the primary heavy gas oil pump vaporized, leading to the dispersion of the vapor cloud. The operators who responded were wearing bunker gear and several wore emergency respirators. Those with respirators isolated the pump from the pipe line by closing the suction and discharge valves. The operators who were not wearing emergency respirators stationed themselves upwind of the vapor cloud and put water on the cloud; however, the wind changed direction several times, exposing unprotected operators to vapors. Employees #1 and #2, two unprotected operators who responded to incident, were brought to Long Beach Memorial Hospital to be treated for inhalation of hydrocarbons. Employee #1 was hospitalized.
Source: osha.gov

December 3, 2019

35 years after Bhopal- lessons still being learnt!

35 years ago, on the night of December 2nd/3rd 1984, the Worlds worst industrial disaster took place.

In India and elsewhere around the World, catastrophic chemical plant incidents continue to occur. Memory is short. In the numerous incidents since Bhopal, many of the reasons are similar to those of the Bhopal disaster:

  • cost cutting without properly analysing the effects on process safety
  • poor competency
  • poor asset integrity
  • high attrition rate
  • inadequate emergency response and planning
  • inadequate facility siting
  • not paying heed to audit reports and past incidents etc.
What has changed between 1984 and 2019? It is technology. But can technology change behavior of people? In 2010, two fatal accidents occurred at two different sites of one of the World's best process safety managed organization. Why? Think about it!

Even if you have a 40 element PSM system, there is no guarantee that a catastrophic accident will not occur.  Is there a solution to this? One of the possible solutions is accountability at the highest level. By this I mean legal requirements that will make the entire board of chemical organizations accountable for a process incident that kills or maims people. The Sword of Damocles should surely work.
We still do not have any PSM rule in India apart from the OISD guidelines for the oil sector. We still do not have an independent incident investigating authority. The status of the chemical safety and security rating system whose draft was published few years ago is not known.

My thoughts are with the victims of Bhopal - dead and surviving...and I pray that another Bhopal does not occur.

Read my earlier posts on Bhopal:

See a presentation on the Bhopal Gas Tragedy by Vijita S Aggarwal, Associate Professor, University School of Management Studies,GGS Indraprastha University,Delhi, India in this link.
Read my older post comparing the Bhopal and the BP incident of 2005 in this link
Read the then Police Chief’s account of the tragedy in this link.

November 30, 2019

Water hammer accident

A five-person crew was valving in a second stage reheater at an electric power generation station. They were slowly opening two valves to bring the reheater online. Two of the employees were stationed at one valve, and the other three were at the second valve. Two other employees were working in the immediate area, observing the reheater's drain tank levels after having adjusted an automatic valve about 30 minutes before. The drain line for the reheater ruptured downstream of the valves, releasing steam and hot water into the area. The rupture was caused by excessive pressure in the line as a result of a water hammer. The water hammer was caused by the presence of lower pressure on the downstream side of the valves than on the upstream side. This produced a back flow in the line. The operating procedure for the valves in the line during start up operations had been changed earlier in the year to eliminate water hammer that had occurred previously. However, the new changes were not incorporated into the written operating procedures being used at the time of the accident. Seven employees (all five members of the work crew plus the two other employees working in the area) received second-degree burns to multiple parts of their bodies. They were hospitalized for their injuries.

November 27, 2019

Steam flushing incident

At approximately 9:30 a.m. on January 19, 2005, Employee #1 and Employee #2, were isolating and cleaning a series of three pumps at a refinery in California, while Employee #3 observed the cleaning operation from a distance. The three workers were starting up the refinery's crude unit. They were experiencing screen plugging from crude unit particles inside the crude unit's prefractionator reboiler pump (pump). The screens commonly become plugged during start-up operations. After the charge pump is isolated, workers clean the pump body by injecting pressurized steam into it. Normally the mix of residual crude oil and pressurized steam is removed through a small outlet in the valve body. Employee #1 connected a 40 psi steam line to the top of the pump body. The flexible removable steam line connects to a Chicago fitting on the top of the pump. Just before the explosion, Employee #1 had cracked open the steam line, letting steam into the pump. An uncontrolled pressure event immediately ensued. The overpressurization of the pump body assembly caused the pump suction flange, strainer outlet flange, and flex connector to blow out violently. The spraying hot oil and the fire started by the explosion caused burns to Employees #1, #2, and #3. Employee #1 sustained third and second degree burns over 50 percent of his body and later died. Employee #2 suffered first and second degree burns over his back. Employee #3 suffered first degree burns on his face. Employees #1 and #2 were treated at the Hospital. Employee #3 was treated locally.
Source: OSHA.gov

November 24, 2019

OSHA's Top 10 Most Frequently Cited Standards FY 2018

OSHA's Top 10 Most Frequently Cited Standards 
(Source: https://www.osha.gov/Top_Ten_Standards.html
for Fiscal Year 2018 (Oct. 1, 2017, to Sept. 30, 2018).

The following is a list of the top 10 most frequently cited standards following inspections of worksites by federal OSHA. OSHA publishes this list to alert employers about these commonly cited standards so they can take steps to find and fix recognized hazards addressed in these and other standards before OSHA shows up. Far too many preventable injuries and illnesses occur in the workplace.
  1. Fall protection, construction (29 CFR 1926.501) [related OSHA Safety and Health Topics page]
  2. Hazard communication standard, general industry (29 CFR 1910.1200) [related OSHA Safety and Health Topics page]
  3. Scaffolding, general requirements, construction (29 CFR 1926.451) [related OSHA Safety and Health Topics page]
  4. Respiratory protection, general industry (29 CFR 1910.134) [related OSHA Safety and Health Topics page]
  5. Control of hazardous energy (lockout/tagout), general industry (29 CFR 1910.147) [related OSHA Safety and Health Topics page]
  6. Ladders, construction (29 CFR 1926.1053) [related OSHA Safety and Health Topics page]
  7. Powered industrial trucks, general industry (29 CFR 1910.178) [related OSHA Safety and Health Topics page]
  8. Fall Protection–Training Requirements (29 CFR 1926.503) [related OSHA Safety and Health Topics page]
  9. Machinery and Machine Guarding, general requirements (29 CFR 1910.212) [related OSHA Safety and Health Topics page]
  10. Eye and Face Protection (29 CFR 1926.102) [related OSHA Safety and Health Topics page]
OSHA's 2018 Top 10 Most Frequently Cited Violations - Graphic includes illustrations of the Top 10 most frequently cited violations