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

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

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.

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

Follow procedures for recomissioning mothballed equipment

https://www.nopsema.gov.au/assets/Safety-alerts/Alert12.pdf

Low temperature failure incident

Three nozzles on top of a reactor suffered cracks in the welds during decommissioning of a high-pressure lube oil hydrogenation unit when it inadvertently discharged liquid nitrogen into three reactors. Excessive shrinking occurred, caused by thermal shock.
Damage that occurred to equipment is estimated to be approximately US$55,000 (1999).
Source:IChemE

Managing Change to Drive Chemical Process Safety Management

Managing Change to Drive Chemical Process Safety Management

Fire protection impairment

https://www.agcs.allianz.com/assets/PDFs/ARC/Risk%20Bulletins/Property/ARC%20Fire%20Protection%20Impairment%20Management%20%28English%20US%2009-Mar-2018%29.pdf

Accident in Sewage Treatment plant

Employee #1, the lead operator of a sewage treatment plant, noticed that the residual levels had dropped in the tanks, and he decided to add more ammonium hydroxide to increase the residual levels. Employee #1 removed the camlock fitting and line from an empty 335 gallon tote and installed it to a full 335 gallon tote containing ammonium hydroxide solution. While installing the camlock fitting and line onto the full tote, he failed to secure the camlock fitting latches into the valve coupling grooves.

As Employee #1 turned the valve to the open position, the camlock fitting and line sprung off the coupling and sprayed ammonium hydroxide onto his upper legs and groin area. Employee #1 immediately turned off the valve and secured the camlock fitting latches into the coupling grooves. He then went to the emergency eyewash/shower, approximately 120 feet away, to rinse off the ammonium hydroxide. Employee #1 rinsed for approximately 15 minutes, but did not take off his clothing.

He then drove a golf cart to the administrative building, to notify management of the accident. Management summoned emergency medical services at approximately 9:45 a.m. and rinsed Employee #1 with an emergency eyewash/shower, located in the administrative building, until the ambulance arrived. Employee #1 was transferred to the hospital via ambulance at approximately 10:00 a.m. He was hospitalized for two days for treatment of chemical burns to his upper legs and groin areas.
The use of ammonium hydroxide to control residual levels in tanks was a new process at the facility. No written procedures or hazard assessments were completed for the assigned task. Employee #1 was wearing safety glasses but no other form of PPE during the accident. Employee #1 said he was in a hurry and normally would have worn rubber gloves and a respirator while transferring the camlock and line from one tote to another.

 Source: Fire Analysis and Research Division,National Fire Protection Association

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

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

A temporary change causes a fatality

Temporary changes are dangerous if not managed properly. Read about an incident involving a temporary change that causes a fatality. This incident highlights what Dr trevor Kletz used to say "We do not know what we do not know"
Read the incident in this link.

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

Hydrogen explosion incident due to a change

A company, which produces metal catalysts had made a modification to one of its reactors.
An explosion occurred on the first day of production following the modification and blew the lid through the roof of the factory.


Read about the incident in this link


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

MOVING PROCESS SAFETY INTO THE BOARD ROOM - ARTICLE IN CHEMICAL ENGINEERING PROGRESS

To all my readers,

My article "Moving process safety into the board room" has been published in the September 2015 issue of Chemical Engineering Progress of American Institute of Chemical Engineers.

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

Process Safety Challenge

PROCESS SAFETY CHALLENGE

A fertiliser plant burns natural gas in a hot air generator and uses the hot air to dry the product. The natural gas line inside the enclosed fertiliser plant building is getting corroded due to the corrosive atmosphere inside. Recently, a leak occured in the natural gas line due to corrosion. The NG line pressure is 2.5 barg. A suggestion to enclose the NG line inside the building with an enclosure and providing gas detectors within that enclosure has been raised. You are the MOC (management of change)  approving authority. Will you agree for this change? If not, please list down your comments.

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

Case study of fire incident in VGO-HDT unit by OISD

Read the case study of fire incident in VGO-HDT unit by the Oil Industry Safety Directorate in this link


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

Bypassing overrides and the metro incident

The recent incident in the Delhi metro where the train travelled some distance with the doors open has a parallel to process safety. Apparently, problems were observed by the driver with the door closing system and he requested permission to override it and operate it manually. After getting the permission, he apparently did operate the doors manually in a few stations, but forgot to do so at one.

When you authorise trip or override bypasses due to a malfunction, the sense of vulnerability must increase ten fold with close supervision to prevent human error remember WHERE HUMAN, THERE ERROR!

Read the article mentioning the incident in this link. 


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

Management of Change survey

Dear Readers,
Kindly take a few minutes to complete a Management of Change survey (6 questions, multiple choice) in this link.

Date of closing of survey is 24.7.13. Results will be published in blog. Thank you for your participation.


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

Modifications and HAZOP's

The Management of change element of PSM requires that a PHA be carried out when carrying out modifications. The problem I see in many companies is the lack of continuity of a PHA team due to resignations and retirements. However many checklists and procedure we write, a good PHA depends on the skills of the team leader. With people moving in and out as the PHA chair, the PHA study suffers. No PHA software can replace the skills of a trained PHA facilitator. Whenever a PHA facilitator is changed, go through your facilities management of organizational change procedures and ensure that the requirements of a PHA facilitator are met.

Laser scanning - a tool for Management of change and Asset Integrity

The most difficult elements to implement in a PSM program are management of change and asset integrity simply because of the large quantity of data involved and less time available. I was reading an interesting concept of laser scanning in an article in Power magazine. It mentions the following:
"Laser scanning also provides a dimensionally accurate representation of the plant and all its equipment as well as a photographic quality visual representation. The laser scan database can be integrated with a variety of plant design applications to provide comprehensive facility management support".
The concept will be very useful for PHA teams who are analysing changes/modifications as they can virtually "see" the proposed modification. It is also an useful tool for managing your asset integrity as another article mentions.
Read the article on laser scanning in this link
Read the article on Virtual asset integrity management in this link.

A change in piping material may overlook something else!

A plant decided to change its sulphuric acid piping from Cast Iron to SS. However, they decided to conduct piping design analysis as per code requirement.The analysis found out that design did not adequately consider the difference in cross-sectional thickness between Cast Iron and SS (Cast iron is very thick compared to stainless steel). Also, the heat transfer rates of CI and SS differ. The piping expert redesigned the piping system to account for the thinner cross-section and thermal expansion properties of stainless steel and thus avoided premature failure. 
Read the article in this link.

Cutting cost at what cost?

Recently, a low cost airline has been grounded in Australia allegedly for safety violations. In the chemical industry, too, cutting cost and maintaining competitiveness is the order of the day. But how can you cut cost without compromising process safety? Many organizations have institutionalized risk based approaches towards cost cutting initiatives. But I find that competency of the personnel using such approaches is key to its success. Top management oversight of such risk based approaches can be effective only of someone at the top understands process safety and the implications of a cost cutting change or modification . I often observe some cost cutting changes slipping through such risk based approaches as they were wrongly evaluated by the person doing the evaluation. Ensure you have robust risk management systems and more so, that a person at the top management level is providing management oversight of the whole process. This person must be competent in process safety and risk based approaches. You cannot compromise on this. Act before it is too late. At least the aviation industry has someone external to it to oversee its safety. But in the Chemical Industry, organisations must watch out for this.