Showing posts with label Incident Investigation. Show all posts
Showing posts with label Incident Investigation. Show all posts

March 20, 2022

Classic Marmaduke: Marmy's First Lesson

Classic Marmaduke: Marmy's First Lesson: Steve Elonka began chronicling the exploits of Marmaduke Surfaceblow—a six-foot-four marine engineer with a steel brush mustache and a foghorn voice—in POWER in 1948, when Marmy raised the wooden mast of the SS Asia Sun with the help of two cobras and a case of Sandpaper Gin. Marmy’s simple solutions to seemingly intractable plant problems remain timeless. This Classic Marmaduke story, published more than 50 years ago, reminds us that even the most modern steam plant is only as good as its operators.

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

August 29, 2016

Investigation report on Ammonia gas leak

A few posts back, I had written about the ammonia gas leak in a Bangladesh DAP plant that affected many. The district administration's investigation has determined the following:
  • The company constructed the 500-tonnes reserve tank in 2006.The tank was filled with 250 tonnes of ammonia gas when it collapsed on the night of Aug 22.
  •  Tank was maintained by unskilled staff. Five essential safety equipment, that were needed to prevent the tank’s collapse, had been out of commission for a long time.“The two pressure gauges of the tank were out of order long before the accident took place. Both the pressure transmitters of the reserve tank were inoperative. The condenser, safety valves and pressure vent were also out of order,” said the investigator. 
  •  The factory’s operation department had informed the maintenance department about the faults but they did not pay heed
  • The gas spread far and wide so rapidly because the fire hydrant system of the fertliser factory did not work after the accident.”
Read the article on the investigation in this link.


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January 22, 2015

Process safety incident investigation board - white paper by AIChE

Good paper on Process Safety Incident Investigation Boards by AIChE. India needs one like this.
 http://www.aiche.org/sites/default/files/docs/org-entity/process_safety_investigation_boards.pdf

Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety Management"

January 13, 2015

Rules for process incident investigation

The most important thing in communication is hearing what isn't said." -- Peter Drucker, Austrian-American writer and management consultant
Adapting the above to process incident investigation, I came up with this:
"The most important thing in process incident investigation is hearing what isn't said and seeing what isn't seen."
I have investigated a number of fatal accidents in the CPI and this is true in all cases!

Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety Management"

January 9, 2015

Elk River Chemical Spill incident investigation report

See the investigation report of the Elk River chemical spill in the following link. It is a classic case of ignoring multiple warnings


 http://www.ago.wv.gov/Documents/010815-ElkRiverChemicalSpill.PDF


Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety Management"

January 5, 2015

Refinery leak sealing incident investigation report

In November 2013, an accident during a leak sealing operation on a steam valve killed two technicians in a refinery in Europe. The lessons learnt from this incident are given  in this link
Share it will all relevant personnel. It may save a life.

 Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety Management"

September 3, 2014

Root causes - Unveil them to prevent future incidents

Often, I see incident reports where it mentions the root causes of the incident, but actually they are not the root causes.
I am taking the example of a case study put up on the OISD website called Fire Incident in Process Cooling Tower
in which it mentions the following as "Root Causes" for the incident: My comments are given in brackets.


ROOT CAUSE

1. The reason for explosion and major fire is gushing out of entrapped hydrocarbon from the cooling water return header to new cell, which got ignited since hot jobs were being carried out in close vicinity. The ingress of hydrocarbon was from leakage of hydrocarbon in cooler/condenser in connected process units.
(This is the direct cause of the incident)


2. 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.
(Why was the work not stopped before commissioning of a new facility? Why was hazard analysis/risk assessment not carried out?)

3. Failure to prevent 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 at fag end of the day.

· Improper coordination amongst Operation, Maintenance and Project  departments.

· Unable to ensure the gaps identified in internal safety audit & operation check-list are liquidated before commissioning


(Why was the commissioning done even though several jobs were unfinished?)


I am hoping the OISD will publish the detailed investigation report of the HPCL Visak cooling tower fire incident and the GAIL pipeline leak incident, just as they have put up the Mr MB Lall's committee report on the Jaipur oil depot fire on their website.

 
Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety Management"

October 31, 2013

HPCL VISAK REFINERY FIRE INCIDENT INVESTIGATION

An investigation of the cooling tower explosion in HPCL Visak refinery by the joint chief  inspector of factories suggests that "HPCL failed to adopt safety steps"
Read the article in Times of India in this link.

Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety management"

March 15, 2012

Update on China pesticide factory explosion

Further to my earlier post on an explosion in a pesticide factory in China, a newspaper report indicates the following:
"The investigation found that a heat transfer oil spill under one of the three chemical reactors inside the factory caused a fire that heated the ammonium nitrate and guanidine nitrate in the reactor. Both compounds are used to make explosives and explode at high temperatures.
This caused one reactor to explode, triggering a second, massively destructive blast in the plant. "The blast revealed severe problems with the production processes at the Keeper Chemical factory," according to the investigation statement.
The factory was poorly equipped, had low safety standards, and most procedures require human labor, according to the statement. Further, the factory altered the raw materials and the heat transfer oil system without assessing the risk. In addition, the workers were unqualified. Most of them, including the head of the workshop, were middle school graduates without education in chemical production. "The workers had low qualifications for dealing with emergencies and did not meet the requirements for chemical factory production," the statement said".

Read the report in this link.

January 17, 2012

Learning from Buncefield

The Buncefield incident in 2005 was a wake up call for the industry. A lot of assumptions that were in vogue till then in QRA were overturned. Henry Troth has made a good presentation of the incident mentioning the following:
  • "Take a critical look at your Safeguards, your Prevention and Mitigation Layers – they may not be as effective as you need
  • Tanks should have overfill lines from HHH down to ground level to reduce splashing and vaporizing overflowing fuelTank 
  • Overfill Protection should be SIL rated and proven in use
  • Retrofit water curtains on closely spaced tanks
  • Fire Pump House should not be a source of ignition (classified area)
  • Store portable fire fighting equipment and foam in a ‘safe’ place -stationary equipment usually gets knocked out.
  • Remember – you must keep all Safeguards working as well as the SIS layer(s) – otherwise you are exposed
  • Is a spill all you need to worry about (what could possibly go wrong)?
  • Consider consequences carefully – What will you do if the unthinkable happens?"
Download the presentation from this link.

January 15, 2012

Investigating process incidents

"Aerodynamically, the bumble bee shouldn't be able to fly, but the bumble bee doesn't know it so it goes on flying anyway" - Mary Kay Ash, American Businesswoman
I like this saying as it is very relevant to process incident investigation. In the course of investigating many process incidents, I have come to the conclusion that you need to be like the bumblebee (keep your mind open, and avoid jumping to conclusion!) while investigating incidents. Many chemical process incidents may apparently not reveal the root causes immediately. I have used the event and causal factor analysis/barrier analysis and Man-Technology-Organization analysis to determine the root causes of many chemical incidents. Also, listen to the people who were present during the incident and observe the incident site. Equipment tell silent tales.

August 21, 2011

Hydrogen peroxide accident kills two

Thanks to Abhay Gujar for sending information about an accident in a chemical unit in Hyderabad tht has killed two women. As per the Times of India article, "The incident took place at 11.30am when the two workers were mixing hydrogen peroxide, methyl ethyl ketone and sodium sulphate to produce a chemical substance used in the manufacturing of asbestos sheet moulds and coolants. The high intensity of the explosion damaged a portion of the chemical unit's roof and severely injured both Venkata Lakshmi and Kalpana". Read the article in this link.

The MSDS of hydrogen peroxide warns of the following:
"Soluble fuels (acetone, ethanol, glycerol) will detonate on a mixture with peroxide over 30% concentration, the violence increasing with concentration. Explosive with acetic acid, acetic anhydride, acetone, alcohols, carboxylic acids, nitrogen containing bases, As2S3, Cl2 + KOH, FeS, FeSO4 + 2 methylpryidine + H2SO4, nitric acid, potassium permanganate, P2O5, H2Se, Alcohols + H2SO4, Alcohols + tin chloride, Antimoy trisulfide, chlorosulfonic acid, Aromatic hydrocarbons + trifluoroacetic acid, Azeliac acid + sulfuric acid (above 45 C), Benzenesulfonic anhydride, tert-butanol + sulfuric acid, Hydrazine, Sulfuric acid, Sodium iodate, Tetrahydrothiophene, Thiodiglycol, Mercurous oxide, mercuric oxide, Lead dioxide,
Lead oxide, Manganese dioxide, Lead sulfide, Gallium + HCl, Ketenes + nitric acid, Iron (II) sulfate + 2-methylpyridine + sulfuric acid, Iron (II) sulfate + nitric acid, + sodium carboxymethylcellulose (when evaporated), Vinyl acetate, trioxane, water + oxygenated compounds (eg: acetaldehyde, acetic acid, acetone, ethanol, formaldehyde, formic acid, methanol, 2-propanol, propionaldehyde), organic compounds. Beware: Many mixtures of hydrogen peroxide and organic materials may not explode upon contact. However, the resulting combination is detonatable either upon catching fire or by impact.
EXPLOSION
HAZARD: SEVERE, WHEN HIGHLY CONCENTRATED OR PURE H2O2 IS EXPOSED TO HEAT, MECHANICAL IMPACT, OR CAUSED TO DECOMPOSE CATALYTICALLY BY METALS & THEIR SALTS, DUSTS & ALKALIES. ANOTHER SOURCE OF HYDROGEN PEROXIDE EXPLOSIONS IS FROM SEALING THE MATERIAL IN STRONG CONTAINERS.UNDER SUCH CONDITIONS EVEN GRADUAL DECOMPOSITION OF HYDROGEN PEROXIDE TO WATER + 1/2 OXYGEN CAN CAUSE LARGE PRESSURES TO BUILD UP IN THE CONTAINERS WHICH MAY BURST EXPLOSIVELY.
"