Process safety and competency

In the next decade, the key process safety issue for India is going to be process safety competency. The average age of the Indian Workforce is today reported to be about 27 to 30 years and as experienced personnel leave the organisation, a huge process safety knowledge deficit is arising. The process safety competency gap is observed right at the top in some organizations to the bottom of the pyramid. Only those companies in the CPI who recognize that process safety competency is a a huge business risk will be able to safely manage their processes.
Read what one global organisation is doing about competency in this link.

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

Speech by Judith Hackitt CBE,HSE Chair

I have highlighted some important points made by Judith Hackitt, HSE Chair in a speech tilted "Applying effective leadership and enhancing competency improvement in hazardous industries:
"Everywhere I go there seems to be a growing level of interest and stated commitment to process safety, but sadly this does not always translate into consistent measurable improvement in performance. For example, in Great Britain where we require major hazards industries to report loss of containment to HSE, in the last year alone there have been over 100 loss of containment incidents, more than half of which were considered to be precursor events for a potential major accident. That equates to an average of two loss of containment incidents every week, one of which had the clear potential to develop into a major catastrophe. I use these statistics to illustrate the magnitude of the problem which we all face, I am not suggesting that there is a greater problem in Great Britain than elsewhere but it does highlight why we should all be concerned. Sooner or later one of those "potential" catastrophes will become a real one, somewhere. Our luck is going to run out.

 Automation and process control has brought many benefits but has also increased the remoteness of the process itself and the hardware from the vast majority of people. Process operators now monitor and control processes via computer screens and increasingly complex process control systems which run the process much more steadily and reliably also can create a false sense that the computer wouldn't let things go wrong.

• Smoother running can also have an impact upon the level of attention which is afforded to engineering knowledge and concerns. Pressures to deliver reduced costs and better returns have placed requests for inspection and maintenance in the "problem" box. Shutting down a process to carry out inspection is resisted and schedules are pushed out. In many cases the value of preventive maintenance which we all learned a long time ago when Kaizen and Total Quality Management were very high on everyone's agendas has been replaced by a drift back to "If it isn't broke then we don't need to stop to fix it". And even when it is broke - let's just patch it up.
• Economic variations can also lead to assumptions being made which turn out to be wide of the mark. In the case of the UK's North Sea oil and gas operations, back in the 1990s with oil prices at a low level it was widely assumed that assets were coming to the end of their operating life and maintenance was therefore cut back, but those neglected assets are now being called on to operate again at high levels and well into the foreseeable future. Catching up on poorly maintained assets is by no means easy – it is costly and it takes a long time to rebuild integrity - and confidence.
• Failure to understand the true role of those who are charged with managing safety can also be a factor, especially by senior managers and leaders. Those whose job title is "safety management" are there to ensure that everyone else is playing their part in managing safety as an integral part of every person's job. It is not to do it for them and most certainly it is not possible for senior managers to delegate the leadership of safety to one director or individual. Acting as the conscience or the champion of safety within an organisation is one thing, fragmentation of functions to the extent that senior managers believe that safety responsibility belongs with someone else is another.
• Change in ownership and contractorisation or outsourcing of activities has been a widespread feature of many parts of the process industries for some years now. Contractorisation leads to the potential for further diffusion and possible confusion about who is responsible for what, including safety. Change of ownership is an increasing cause for concern, in that it is unclear what documentation and knowledge about critical issues such as basic design principles are passed on when assets change hands.
• Advances in technology.  I have already mentioned that modern plant that incorporates state of the art equipment has brought with it great benefits in terms of increased reliability, less excursions from normal operating conditions and so on. But the trade off to this can be a growing sense of complacency that the sorts of problems which had happened in the past could not happen again and that they have been fixed. Over time the corporate memory of what can go wrong and the consequences of things going wrong and how important it is to avoid such catastrophic events can fade  for everyone – senior managers and operators - resulting in a growing lack of understanding and appreciation of the importance of process safety, especially at the most senior levels. Ultimately, this can lead to a situation where the right questions are not being asked by the leaders of an organisation because they didn't even realise or understand what needs to be asked." 

 Read the complete speech in this link

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

Risk management in CPI

A good article in the Business Standard highlights the importance of risk management. I know of a chemical industry where the Chief of safety has been designated as "Chief Risk Officer". For a chemical manufacturing facility, apart from the financial and other risks, the risk to reputation and business continuity if an incident occurs is much higher. The article in the Business Standard mentions the following:
'Even Mukesh Ambani in a way is striving to protect his revenue streams by diversifying into homeland security. “If you want a safe Jamnagar, or a safe Mumbai, you might as well offer the best security solutions to the nation’s top cities and its energy assets. It’s also linked to strategic energy security,” says a senior RIL executive, who did not wish to be quoted."
Read the article in this link.

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

Explosion in boiler due to acid cleaning

Two people were killed when an explosion occurred in a acid cleaned boiler. The explosion occurred when a an ordinary halogen lamp was inserted inside. The investigation report mentions the following:
"The most likely cause of the accident was the ignition of hydrogen gas that built up in the starboard boiler steam drum. The hydrogen accumulation occurred because of inadequate ventilation arrangements to release the gas to atmosphere, as it evolved during the chemical cleaning procedure. As the steam drum door was opened, air was drawn in and combined with the hydrogen gas to produce a mixture between the hydrogen’s Lower Explosive and Upper Explosive Limits. This potentially explosive gas was not ventilated to atmosphere, nor was the confined space of the steam drum tested for toxic or flammable gases in accordance with normal practice. As the non-intrinsically safe, halogen lamp was passed into the steam drum, either the high temperature of the halogen bulb or lens glass, or an electrical spark from the lamp, ignited the gas and caused the explosion
Southampton University’s report at Annex O clearly explains how hydrogen gas can evolve when using sulphamic acid to clean steel structures such as boilers. A conservative estimate was made of the amount of hydrogen gas that was likely to have evolved through contact with the steel in the starboard boiler. This estimate, which did not consider the interaction of other possible contaminants, was based on the assumption that there was no effective ventilation and the inhibitor was 95% efficient. The report determined that, at the point of opening the steam drum, there would have been about 2.7m3 of hydrogen present, giving a hydrogen air/mix of about 55%. This is well within the hydrogen LEL and UEL range of 4 -75%, i.e. an explosive mixture existed in the steam drum"
Often heat exchangers and new equipment are acid cleaned using sulphamic acid, in chemical industries. Ensure that your personnel as well as the contractor personnel who are doing the job are aware of the hazard of hydrogen generation in the process of acid cleaning. I would like to know from readers whether they have experienced any similar incident and what are the precautions you follow.

Read the detailed incident report in this link.
 
Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety Management"

Molasses tank leak

A news item mentions that a molasses tank in a sugar factory in Odisha had developed a crack and molasses entered the " staff quarters" and killed three persons.
Read the article in this link.
 
Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety Management"

Horrible confined space incident

Two metalworkers were "cooked" inside an oven after a worker mistakenly switched it on. The news report mentions "Detectives investigating the horrific deaths in the massive oven say the pair had tried to rip the insulation off the wall of the oven and clawed at the door in a desperate bid to get free".
Ensure you follow all your confined space entry procedures, including lock out, tag out and try procedures.
Read about the incident in this link.
 
Contribute to the surviving victims of Bhopal by buying my book "Practical Process Safety Management"

Major gas leak from oil rig

A major gas leak from an oil rig in the North sea has been reported. The gas has not caught fire yet. The rig and surrounding ones were evacuated. The flare on the rig continued to burn but the wind direction was blowing the gas away from the flare. Read/ see the videos in these links:
Link 1
Link 2

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

Fatality due to fall through removed grating

Thanks to Senthilkumar for sharing news of a fatal accident due to fall through a removed grating:
"At the filtration section of a Phosphoric Acid Plant plant maintenance personnel were lifting a 3 meter filter cloth through a removed grating at the filtration floor at 12 m height. The filter cloth was being removed every four weeks. To lift the filter cloth, the gratings are removed and fixed back every time after lifting/replacement of the filter cloth. Unfortunately the same operator who was watching the lifting activity stepped in to the open hole (of the removed grating) while talking in a radio. He died because of the fall from from 12 m height to ground level".
Removed gratings are very dangerous. During erection or maintenance stages, ensure you have proper control over them. 

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

Confined space and gas detectors

Thanks to S.Selvam for sending news about an incident where the gas detector used for confined space tests was out of calibration.Read about the incident in this link.
 Another article by Concept Controls mentions the following:
'There has never been a consensus among manufacturers regarding how frequently confined space gas detectors need to be calibrated. However, manufacturers do agree that the safest and most conservative approach is to verify the
performance of the instrument by exposing it to known concentration test gas before each day’s use. This functional “bump test” is very simple and takes only a few seconds to accomplish. It is not necessary to make a calibration adjustment unless the readings are found to be inaccurate. The regulatory standards that govern confined space entry
procedures are in agreement with this approach'.
Read the article in this link.

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

Lessons to learn from safety report of Railways

The Indian railways high powered committee on rail safety has published its report. There are two recommendations in the report which also apply to process safety management in India. I am quoting from the report: "There is no practice of independent safety regulation by an independent agency separate from operations. The Railway Board has the unique distinction of being the rule maker, operator and the regulator, all wrapped into one. Commissioners of Railway Safety though considered to be the safety watchdogs have negligible role at the operational level. Compliance of safety standards set by Railways for themselves are often flouted for operational exigencies. The Committee has recommended a statutory Railway Safety Authority (RSA) and a safety architecture which is powerful enough to have a safety oversight on the operational mode of Indian Railways without detaching safety with the railway operations. The Committee has also recommended measures to strengthen the present Railway Safety Commission to undertake meaningful regulatory inspections" IR suffers from ‘IMPLEMENTATION BUG’. Implementation of accepted recommendations of the previous safety committees has been a major issue. The Committee has recommended an empowered group of officers in Railway Board to pilot the implementation of the recommendations in a time bound manner with full funding. The Committee has also recommended the review of implementation of recommendations by the new statutory outfit of Railway Safety Authority under Government of India. In India, we need to make PSM mandatory and bring an independant investigating authority like the CSB. Also, the recommendations of safety audits need to be followed up. Read the full report in this link.

Capacitor failure incident

An interesting incident of a capacitor failure aboard a ship is reported.
Chemical plants use capacitor banks to improve power factor and there are lessons to learn from this incident.
Read about the incident in this link.

Fire in Chemical Tanker

A fire has been reported in a chemical tanker in Mumbai. It appears that toluene was unloaded and "stripping" operations were on when the fire occurred.
Read about it in this link.
UPDATE: An explosion has occurred in the same vessel reportedly injuring 7 petrsonnel, one critically. Read about it in this link.

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

Murphy's technology laws

I came across some interesting technology laws from Murphy! The best I liked were:

1. "The degree of technical competence is inversely proportional to the level of management.
2. Logic is a systematic method of coming to the wrong conclusion with confidence.
3. Technology is dominated by those who manage what they do not understand". 

No harm intended to anyone......but it is of relevance to PSM today!!!!

Read many good ones in this link

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.

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.

More confined space accidents

"A plumber was attempting to warm a confined space in which he intended to work. He placed his lighted cutting torch in the vaulted area and closed the opening. When he returned to the vault, he noticed that the torch was no longer lit and, after entering the vault, attempted to relight the torch. The torch had used up the available oxygen in the space, causing it to extinguish, and filled the space with acetylene. When the plumber reopened the space, oxygen was again introduced and the ignition caused the acetylene vapors to ignite. The plumber was blown out the opening and burned over 65% of his body. He died about a week later."
Read about this accident and 11 other confined space accidents in this link

Accidents in batch processes

See this link for few accidents connected with static electricity and reactivity in batch processes. There are lessons to learn.

Rupture of a rubber lined vessel

A rubber lined vessel was taken out of service to replace the rubber lining. The vessel was taken to the rubber lining works and it was heated with external propane torches after blanking off all openings. Workers heard a whistling noise and ran way. A few moments later the vessel exploded. Heating the vessel externally caused the vessel to over pressurize and rupture. Read the case study in this link.

On line leak sealing

Sorry, the previous post on online leak sealing had a bad link....
Recently, I had met a senior colleague of mine called Mr S.Raghavachari after a gap of 20 years. While reminiscing about the "good old days", I remembered that he had written about online leak sealing. I mentioned about my blog and he promptly sent his article on the subject to share with readers.I thank him for sending the article.
Online leak sealing is effective if all hazards are evaluated. There have been numerous accidents during on line leak sealing, mainly due to the mushrooming of fly by night operators. Be careful while choosing your on line leak sealing contractor. Ensure he has the proper technical background and support.
 You can read Mr Raghavachari's article in this link.

Deadly explosion in pesticides factory

An explosion has taken place in a pesticide factory in China. A news article mentions that "According to the preliminary investigation, the major substance that caused the blast was guanidine nitrate, a combustion-supporting chemical that can irritate the eyes, skin and upper respiratory system. The specific cause of the accident is still under investigation"
Read about the accident and see photo of the blast zone in this link.

Don't make a mockery of a mock drill

The recent unfortunate death of a young woman  volunteer in a mock drill at Bangalore, speaks volumes of the state of emergency preparedness. In many chemical plants, mock drills are conducted by informing everyone about the timing of the drill. What is the purpose of this if you want to test your real emergency preparedness? In 1995 I attended an advanced firefighters and rescue training at Dubai where not only were we made to fight live natural gas fires generated in a natural gas skid mounted mock plant ( we had to isolate the supply of natural gas) but also made to search for victims inside buildings. Smoke bombs were placed inside the buildings to disorient us, along with strobe lights that were flashing ( also to disorient us). The instructors place a lot of emphasis on the safety of the firefighters and rescue team. Recently I read an article about a new training tool for firefighters in this link.
Always be prepared and don't make a mockery of a mock drill.

Silo collapse in fertilizer factory

A silo structure collapse in a fertiliser factory has led to injuries to 15 people.The cause of the incident is under investigation. Ensure that all structures (both civil and structural) are inspected and maintained properly. Sometimes, I have observed fertiliser material covering many structures. What you don't see cannot be inspected. Another article Mentions that police have registered criminal cases against the management.
See the video of the collapsed structure in this link
Read the article in this link.

Meetings and Process Safety

Nowadays meetings are the order of the day. Either the plant manager is coming from a meeting or going to one! Net result - plant visits by the plant manager are rare. Process safety needs to be managed by look,listen and feel technique - look at the plant, listen to your shift crew and feel the pulse of what is going on at the plant level! A newspaper report suggests that attending meetings makes one brain dead. Plant Managers - Beware!!!
Read the news article in this link

Plane accidents and process safety

"06/23/1967 Mohawk Airlines
BAC-111-204AF Blossburg, Pennsylvania The airplane crashed after an in-flight fire destroyed the pitch control systems. All 34 people aboard were killed. A malfunctioning nonreturn valve allowed hot engine bleed air to flow back through an open air delivery valve, through the APU and into an acoustic blanket lined section of the fuselage. This caused flexible hoses with hydraulic fluid to ignite and lead to an uncontrollable fire". Beware of check valves!!

"09/06/1971 Pan International
BAC-111 Hasloh, Germany The aircraft collided with a bridge, shearing off both wings, after a double engine failure occurred during takeoff. The water-injection system to cool the engines during takeoff was inadvertently filled with kerosene instead of water".

30 years ago, an operator in the plant I worked filled up antifoam liquid from a drum similar to an oil drum into the hydraulic governor of a large steam turbine. We found out when the governor started misbehaving!!

Source of plane accidents : http://planecrashinfo.com/unusual.htm

Fire in Pharma factory

Reports of a fire incident in a Pharma factory mention that hazardous waste stored for incineration caught fire. Are you safely storing hazardous waste as per the norms? Generally, what I have observed in other factories is that the incinerator area, being far away from the plant, sometimes gets a little less attention than it should be getting. Most of the work is also contracted out.Ensure that the contractor employees are trained in the norms of handling, storing and processing hazardous waste.
Read the article about the fire in these links:
Link 1
Link2

The importance of emergency stopping

How do you ensure that your emergency stop buttons will work when needed? The emergency stop is the last line of defense and a good article by Robin J Craver mentions the following:
"The nature and operation of the machine must be considered.
· Is it safe to have the emergency stop system cut the power to the machine drives and actuators? This may result in the hazard “free falling” leading to a more dangerous situation.
· Should the system actuate a brake or clamp?
· Would stopping the machine in position result in a worsening of an injury?
· Should the system allow the machine to continue on or reverse to a safe position?"
 Read the article in this link.

Process safety and nanotechnology

With nanotechnology, the process safety hazards will change. A whole new nano process safety approach may need to be taken to identify nano hazards. An article mentions the hazards of nano dust. It mentions that "nanomaterial dust could explode due to a spark with only 1/30th the energy needed to ignite sugar dust — the cause of the 2008 Portwentworth, Georgia, explosion that killed 13 people, injured 42 people and destroyed a factory".
Read the article in this link.

Fire in refinery

A fire in a major refinery in the US has been reported. Apparently, the fire was due to a flange leak.See the video of the fire in this link.

Pressure vessels and labs / R & D's

I have often seen that personnel in labs and R & D setups do not understand the hazards of a pressure vessel. Many times, pilot plants are built by buying equipment from the second hand market. Not having the specifications / data sheet for the vessel is dangerous. One such fatal incident in a NASA lab highlights the following:
"Vessel at least 33 years old
• Unknown prior service, no nameplate, no drawings
• No pressure or temperature rating information
• Most welds on hold down bolts were cracked before being put into this service
.Vessel design inappropriate for intended service
– Vacuum vessel put into service as a pressure vessel
• Vessel not pressure checked prior to full use
– And no restricted access during initial pressurization
• Critical welds on hold down bolts not inspected after 33+ years of existence
– Were not considered critical for a negative pressure (vacuum) application
• Bolt welds were cracked and cracks exhibited corrosion prior to this use
• Vessel failed (chamber lid separated from chamber body) when all hold down bolt welds broke simultaneously".

Read about the incident in this link.

Industrial accidents in India

As interesting article in Livemint.com highlights that statistics of industrial accidents in India are not accurate. It mentions that "Data supplied by two labour ministry agencies show that accident insurance benefits claimed by companies indicate a rate of accidents that far outweigh those that are reported".
Read the article in this link.

Ammonia gas leak incident

IBN Live has reported an ammonia gas leak at Paradeep where 3 workers were rendered unconscious.  The news item mentions that "Sources said some crew members inadvertently handled the gas tank of the ship carrying 13,000 metric tonnes (MT) of ammonia gas meant for the plant. The employees who came in contact with the gas fell unconscious. The unloading of gas through a pipeline to the plant had been completed by then". 
Read the news item in this link.

Vehicles and process safety

An incident where a car hit a chemical storage tote has been reported. Ensure you have identified all possible points of impact of vehicles. Piperacks, storage tanks, culverts, loading/unloading stations are all areas which you should study for a possible vehicle collision. I had been to a large refinery which had expanded in the space available. (There was a huge space deficit). Their staff bus had to cut across two units, along a narrow culvert carrying hydrocarbon pipelines. Its a disaster waiting to happen.
Read about the car accident in this link
 

Dispersion of chlorine and its containment

Thanks to Harbhajan Singh Seghal for sharing his article on " dispersion of chlorine and its containment". Read it in this link.

Management Integrity level (MIL) and Process Safety

There is a lot of talk about safety integrity level and the reliability of control and shutdown systems. While a reliable instrumented system is good for process safety, it is the integrity of management, what I call Management Integrity Level that is more important! By this what I mean is whether management is really interested in process safety by allocating resources, time and competencies. Even if we develop a MIL (Management Integrity Level) rating for management, the score has to be measured and monitored on a continuous basis!
Do not get carried away by SIL ratings and multi coloured QRA's and risk matrices. Look into your organisation and determine whether Management Integrity Levels are adequate! The answer lies within!

The dangers of pressure vessels

A good article - Accidents in Pressure Vessels: Hazard Awareness by Temilade Ladokun, Farhad Nabhan and Sara Zarei Mentions the following:  
The main causes of failure of a pressure vessel are as follows:
Faulty Design
Operator error or poor maintenance
Operation above max allowable working pressures
Change of service condition
Over temperature
Safety valve 
Improper installation
Corrosion
Cracking
Welding problems
Erosion
Fatigue
Stress
Improper selection of materials or defects
Low –water condition 
Improper repair of leakage 
Burner failure 
Improper installation

Read the article in this link.

New pipeline design concept

DNV has released details of a new concept in subsea pipelines called "X stream". The thickness of the pipe is reduced by using inverted HIPPS concept. It is an interesting read. Read it in this link.

Leak detection in sub sea pipelines

An article mentions the use of fiber optics to detect sub sea pipeline leaks based on Joule Thompson effect. Many sub sea pipelines transfer LNG, ammonia etc and any leak in these pipelines will have a catastrophic effect. The article mentions the following: "Fibre Optic Distributed Temperature Sensing (DTS) methods have been successfully applied to many processes in the oil & gas industry. This non-intrusive sensing system proves invaluable in the monitoring of LNG pipelines both for cool down at commissioning, for temperature profiling during operation and as a leak detection system. There is ongoing work in the use of fibre optic DTS systems in the development of smart cryogenic hoses for the transfer of LNG and storage and piping systems aboard floating LNG vessels. Developments in LNG pipes include multi-layer insulated piping systems. This contribution presents recent studies in the use of fibre optic distributed sensors for temperature profiling and leak detection in multi-layer insulated LNG pipes". Read the article in this link.

Are your SOP's clear?

There are lessons to learn from an aborted take off recently at Hong Kong airport. The aircraft commenced takeoff not on the assigned runway but parallel taxiway. The air traffic controller noticed the airplane accelerating on the taxiway and ordered the aircraft to stop. There was no other traffic on the taxiway at the time of the serious incident.A news report mentions the following:
"Hong Kong's Civil Aviation Department (CAD) released their final report concluding the probable causes of the incident were:
- A combination of sudden surge in cockpit workload and the difficulties experienced by both the Captain and the First Officer in stowing the EFB computers at a critical point of taxiing shortly before take-off had distracted their attention from the external environment that resulted in a momentary degradation of situation awareness.
- The SOP did not provide a sufficiently robust process for the verification of the departure runway before commencement of the take-off roll.
- The safety defence of having the First Officer and the Relief Pilot to support and monitor the Captain’s taxiing was not sufficiently effective as the Captain was the only person in the cockpit trained for ground taxi'.

Are your SOP's clear and are your operators trained to handle spurts in workload that occur during an emergency?

Read the news article in this link.

Chlorine tonner incident

Thanks to Mr Harbhajan Singh Seghal for sending this incident:
INCIDENT
In one of the chlorine consuming industry two persons were affected with chlorine while the operator disconnected the tonner from the process due to hard valve operation of the tonner.
DETAILS OF INCIDENT
· The consumer withdraws liquid chlorine from the chlorine tonner and consumes gas after evaporation.
· As per practice, the consumer keeps the tonner in line to withdraw maximum chlorine from the tonner.
· On the specific day of the incident, the operator tried to isolate the tonner at 1.0kg/cm2 pressure when about 40-50 kgs liquid chlorine was left in the tonner and there was ice formation at the bottom of the tonner.
· He could not close the valve fully. The spindle of the valve damaged due to excessive force.
· The operator decided to cut off the tonner by wearing SCBA.
· This action resulted in heavy gas leakage and affected two persons in the surrounding area.
ACTION TAKEN
· The tonner brought to the works.(of the chlorine supplier)
· It was depressurized and the valve was dismantled
· Iron chloride rust and greenish color sludge was observed in the threading of the valve.
· Damaged valve replaced with new valve.
ROOT CAUSE
· Liquid chlorine withdrawal rate is 180 kgs/hr. Maximum liquid chlorine is used up in 4-5 hrs operation at this rate. Some quantity (40-50) kgs remains in the tonner at the bottom.
· Some consumers try to recover this 40-50 kg liquid chlorine as gas by keeping the tonner in line for more time.
· The left over liquid chlorine evaporates at 5-6 kgs/hr as gas and lowers the temperature of the tonner/pipe lines due to fall in pressure till the remaining liquid chlorine is exhausted.
· 1.0 kg/cm2 pressure can lead to about -20 degree C and takes 8-10 hrs to completely empty the tonner.
· Normally chlorine in the tonner is dry. But under such conditions (-200) the same chlorine becomes wet.
· Water in the chlorine separates out and freezes in the spindle of the chlorine valve. It makes the valve hard to operate at that time.
· After attaining normal temperature, chlorine evaporates first and water later. This chlorinated water reacts with the sprindle and makes the chlorine spindle greenish.
· The evaporators which do not have backflow prevention system (from evaporator to chlorine tonner) results carry over of iron chloride rust to valve spindle and makes the valve hard in operation.
LESSONS LEARNT
· The tonners containing some quantity of liquid chlorine (40-50 Kg) are not to be cut off at 1.0kg/cm2. The tonner is to be depressurized by releasing the chlorine to neutralization system through header or evaporator.
· After depressurizing, check that no chlorine gas comes from the upper valve of the tonner, and also check that no ice formation appears on tonner or pipe lines before the tonner is disconnected.
· Chlorine header and evaporator must have chlorine release facility connected to neutralization system.
· Chlorine evaporator must have liquid chlorine flow control interlocked with temperature and outlet pressure to avoid the back flow of chlorine
· Evaporator should have emergency release system with rupture disc and safety valve.
· Temperature of evaporator should be maintained between 80-85 degree C to avoid formation of rust as Fecl3 in the evaporator.
· Dry air (-40 degree) dew point is to be utilized for evaporator maintenance.
· Glass wool filter is to be utilized in gas line to avoid carry over of Fecl3 to main products and choking in chlorine system.
· Tonners can be kept in tilted position forming 20-30 degree angle to withdraw maximum liquid chlorine from the tonner.
MOST IMPORTANT LESSONS
· No chance should be taken with liquid chlorine system. Help of the filler (chlorine supplier) must be taken in such cases. One volume of liquid chlorine expands to 460 times
· Chlorine neutralization system must be effective and checked from time to time.
· Single person should never take this type of emergency job.
· Always stand by person ready with safety equipments should be present during such operations.

Process safety - Seeing and managing

A typical day for today's plant manager is like this: Punch in....login......read emails and answer......collect data for the meetings scheduled......firefight today's issues.......go back home late in the evening! I was just comparing the daily routine i used to do many years ago in the same position: Punch in....go around the plant for at least one hour.......read the log book.....write relevant instructions in the instruction book.....attend the daily plant meeting for discussing and resolving issues....discuss and take instructions from my boss....communicate these instructions to the plant......go back home peacefully, on time! Note: There were no ISO9000,ISO14000,OHSAS18001,PSM,TQM,Six sigma etc in those days! Managing process safety needs management by seeing, hearing and understanding. Unfortunately today's plant managers do not have the time to see the plant.....this is a dangerous trend. Also competency for managing process safety is lacking. Somewhere we seem to have lost our way!

Awards and Accidents

Further to the refinery accident during hot work which I had mentioned in my previous blog entry, an article in the Hindu lists out other accidents that occurred in the same refinery in 2009. It also mentions that the refinery won safety awards in 2009 and 2010. There is a disconnect here! Read the article in this link.
While awards are a good way to motivate people, the onus lies on management to sustain and improve process safety performance.Long ago, I had audited an organization that had been granted a prestigious award by an international organization for their safety management system. I visited the plant 6 months after this award. Their safety management was in shambles and I had mentioned to them that the sword is now hanging over your heads.
If everyone goes back home safely everyday and this is maintained, then your process safety management system is working well! Period.

Worker killed in explosion during hot work

An accident at a SRU at a refinery has killed a worker. Read the article in this link. Please see my earlier posts under safe work practices. Hot work should be done with proper precautions and it is sad that repeated accidents are occuring. 

Process Safety and Risk management in the high speed age

A good article called "Black swans turn grey -The transformation of risk" by Price Waterhouse Coopers highlights the following:

1. The boards of big organisations do not fully understand the risks that they are running
2. In the Internet age, speed and prejudice are all
3. Checks and balances at board level are critical.
4. Leadership and culture shape an organisation’s attitude to risk.

I think in a chemical industry "operational risk" is of greater importance that financial and strategic risks. As long as there are human beings involved in making decisions, there is a possibility of a process safety incident that has serious implications for the business. That's why I agree totally with the Baker Panel report suggesting that a person competent to understand process safety be on the board of Directors for Chemical Industries.
Read the article by PWC in this link.

Oil rig catches fire

An oil rig in Nigeria has caught fire and it is reported that two workers were missing and two are hospitalised. Reason for the fire is not known. Read about the fire in this link.

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.

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.

Fire in Guwahati oil refinery

Read about it in this link.

Three killed in factory explosion in China

The hazards of thermal expansion

Many plant personnel do not give importance to thermal expansion safety valves. These are typically small valves and often, the isolation valves are kept closed as they pass. It is human tendency to ignore small things but in process safety it is the small things that cause big disasters!

The CSB had published a good case study on a fatality that occurred due to the bursting of a heat exchanger due to thermal expansion of trapped ammonia. It is worth reading and sharing with all your colleagues. Read it in this link.
The photo at the left is courtesy of the CSB.
Read another incident in this post. 
Read a third incident in this post

Cyber security for chemical plants

Dr Trevor Kletz has said "what you don't have cannot leak". This was with reference to hazardous chemicals. It makes sense then and makes sense now. But with the advent of Internet and remote operation of chemical plants, we often think that the best way to keep a plants intranet secure is not to connect it with the Internet. In other words, "when you are not connected , you cannot be hacked". Last year, the cyber attack on a nuclear development facility in Iran, caused centrifuges to speed up but the control room did not display the increased speed! It is a very interesting story and just imagine what could happen if a cyber take over of critical equipment in a chemical plant takes place? Ensure your systems are adequately protected and conduct cyber security drills along with your regular mock drills! Read the very interesting article about the centrifuge incident in this link.

Process Safety - Keep it simple

I often think that today we are complicating things too much in process safety, in an already complicated World! This generation of plant operators have been inundated with technology. While some of the technology is excellent, not all of them really help the plant operator. Information overload is the bane of today's PSM programs. When I was a shift in charge at an ammonia plant, we had pneumatic control system (no DCS), but it was so user friendly. I would sit in the center of the control room and at a glance I got to know the plant status. The control room had three operators - one for the front end of the plant, one for the back end and one senior guy looking after both. During emergencies, the senior guy would coordinate the actions very swiftly as he could see the complete plant status just at a glance. The whole ammonia plant had only about 200 alarms that were located on the panel. The critical ones were painted red. By experience we would know which alarm meant what! We never had a serious process safety incident!!I managed to get some pictures to illustrate what I am talking about. 

Our control room looked similar to the one at the left. The table at the center was a flat table. The shift engineer used to sit at this table.The control panel is just below the clock.The flowsheet of the entire plant (called a mimic) was depicted at the panel top

This was a field controller.  See how simple it is! The red arrow is the setpoint.

 This temperature recorder was similar to the one we used to record secondary reformer top temperature and methanator temperature.









The message I am trying to convey is try to keep it as simple as possible. Buy only what you want and not what you get! (This is especially true for DCS and electronic instrumentation)

PSM and PDCA cycle

The PDCA cycle is the core of any management system. I have seen a common trend from investigating root causes of many chemical plant process incidents - it appears that many of the root causes are due to following the PDCA cycle in a different way: DCA,no P -DO, CHECK, ACT and No PLAN! Fire fighting efforts take place to immediately attack an issue. Productivity, cost cutting and efficiency improvements often take place without undergoing the management of change process. This is why I feel that while certifications to OHSAS 18001, ISO 14001, Responsible Care etc are good, the sustainability of such certifications become questionable. This is evidenced by fatal accidents in companies that are certified. How do we solve this issue? I believe that the onus lies with the top management. If top management are clear about process safety and its implications, then you do not need any system at all! Unfortunately, there is a huge knowledge deficit about the technical aspects of running a chemical plant and the importance of PSM. Recently I had implemented PSM in a pesticide manufacturing unit where the head of the unit was a hardcore experienced chemical engineer. His understanding of the technical nitty gritties of PSM helped me greatly during the implementation. I will end my ranting by repeating two things that Dr Trevor Kletz has said and is highly relevant to Process safety management: 1.Walk the talk! 2.Keep it simple!

WISH YOU A HAPPY NEW YEAR!

To all my subscribers and readers,
Wish you and your family a very happy New Year!

Fatality at ammunition factory

A fatal accident at an ammunition factory has even experts "baffled". The article mentions "Mule, a permanent employee, was described as a highly skilled worker. The incident happened around 2.10 pm when he was about to go for lunch. AFK officials said there was a spark and suddenly Mule was on fire. Showing presence of mind, Mule sprinted towards a water tank and doused the fire. Otherwise, the fire could have spread causing much damage, said some of the employees". Maybe static electricity was the cause??
Read the article in this link
Read another article in this link

The dangers of aerosol cans

Yesterday I had been to the birthday party of my friend's eight year old daughter. The kids were playing with an aerosol can which generated foam thread, when pressed. None of the kids were aware of the hazards of the aerosol can and that the gas used as a propellant was flammable! What does this have to do with process safety? We also use aerosol cans for dye checking or lubricating/removing rust etc. Read the warnings on the can before you use them. Propane and butane are often used as propellants and the escaping gas can catch fire if a source of ignition is present. Also do not dispose empty aerosol cans in a fire. They can explode.
Thanks to R.Sriram for sending these tips on aerosol cans:

• Aerosols contain a product and a propellant that are packed under pressure.  
• Many people use aerosols without realizing some of the potential hazards associated with them. 
• Oven cleaners, tile cleaners, pesticides, disinfectants, hair sprays, room deodorizers, paints, and furniture polishes are examples of aerosol products. 
• When the nozzle of an aerosol is pressed, the product and propellant are released from the container in a fine mist. The actual product propelled by the aerosol, such as some oven cleaners, can be corrosive, flammable, or poisonous. Acute symptoms of aerosol exposure include headache, nausea, dizziness, shortness of breath, throat irritation, and skin rash. 
• A misdirected spray can cause eye injury and chemical burns. 
• Never leave or place an aerosol can near high heat sources, such as a heater, direct sunlight, or fire. 
• Keep aerosol cans away from children and pets. 
• Never puncture or subject an aerosol can to sharp impact; a sudden puncture may cause an explosion. 
• Dispose the Aerosols in a proper way.

A water tank kills

A supervisor was killed when he attempted to rescue his fellow worker who had collapsed after entering an empty water tank. Investigation is on to determine what was present inside the water tank. If a water tank can kill, just imagine the hazards you face when you enter a confined space in a chemical factory. Follow your company procedures strictly and don't take any confined space for granted. Read the article about the water tank fatality in this link.

Two killed in pharma factory fire near Hyderabad

A news article mentions that a fire in a pharma factory at Patancheru has killed two people. The article mentions that
"According to police, the fire engulfed the factory after a reactor exploded due to an electrical short-circuit. The fire broke out in the evening, and spread to neighboring factories. Fire-fighting personnel had to battle for five hours to control the flames.This is the second such accident in three days. Four workers of a chemical factory were killed in a reactor blast at Polepalli Special Economic Zone (SEZ) at Jadcherla in Mahabubnagar district near Hyderabad last Friday".
Read the article in this link
See a photo in this link.

The dangers of sewers

Two people were reportedly killed in a factory in Chennai when they entered a sewage tank that was not opened for a long time. Be careful of sewers in your factory and residential colonies. Entry should be done only with proper confined space entry permits

The dangers of water hammer

Many of you would have heard the "banging" noise that a water hammer produces inside a pipeline. We also do not expect a pipeline to be destroyed by water hammer. But it happens. An article by Gregg Basnight mentions the following:
"Contrary to old operating practices to drain and warm up steam lines, "Cracking Open" valves in lines to bleed condensate under steam pressure is NOT safe and has resulted in numerous reported water hammer fatalities.Before admitting steam to any line, the condensate must be removed. Condensate should be assumed to be in all low points and dead legs until proven otherwise by verification of drain or steam trap position and operation. Pressurized dead legs without functioning traps or periodic manual blowdowns will have condensate present. The affected section of piping should be isolated, depressurized and drained before restoring steam to the system".
Read the full article in this link.

Give importance to sight glasses

30 years ago, in the ammonia plant where I worked, the sight glass of a high pressure (200 Kg/cm2) ammonia separator leaked during start up. Luckily we managed to shut the plant down safely with no injury to anyone. The root cause was the wrong torquing procedure used. A good article about sight glasses mentions the following:

"Proper design, installation and maintenance of sight glasses are the keys to their safe and effective use....a sight glass almost always fails in tension rather than compression. This is similar to the case for concrete, because glass is not ductile and cannot stretch like metal. Therefore, tiny imperfections in a sight glass window can create stress concentrations, which are potential failure points. Just the touch of a finger on the window can reduce the tensile strength of a virgin glass element by three orders of magnitude from one million to 1000psi. Although design and manufacturing flaws are important, most sight glasses fail due to improper installation. Mechanical stress is a frequent cause, arising from the over-tightening or uneven torquing of bolts that generate bending loads on the glass. When an existing sight glass window is replaced, trapped debris may become a problem if old gaskets have baked onto the flanges. While this may seem trivial, it is actually very dangerous. Even small contaminant particles or build-up might be enough to scratch, pit or bend the new glass during installation".

Read more: http://www.articlesnatch.com/Article/Sight-Glass-Safety-A-Major-Process-Plant-Concern/1604779#ixzz1gkkBXVxV
Under Creative Commons License: Attribution No Derivatives

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.

US Unions briefing on Process Safety

The USW union of the US has briefed the US Congress about health and safety problems in the oil industry. As per a news article,"USW Health and Safety Specialist Kim Nibarger outlined five fatal flaws at the briefing on where the oil industry needs to improve its health and safety record: process safety, mechanical integrity, management of change, incident investigation and control room alarms and instrumentation. “When things go bad in a refinery, they go really bad and people die,” he told the briefing. “Focusing on personal safety—the wearing of hard hats and safety glasses, slips, trips and falls—says nothing about how safe a refinery is for workers and the surrounding community. BP had a low personal injury rate at its refineries, but the 2005 explosion and fire at its Texas City plant showed it failed miserably in terms of process safety. Fifteen people were killed and 170 were injured in the 2005 accident as a result of this failure. “The oil companies are playing Russian roulette with their equipment,” Nibarger said. “They are doing quick, stopgap fixes, like placing clamps on pipes instead of replacing the pipe. They’re extending the time between unit shutdowns when all the equipment is checked. When there is a shutdown they’re not always repairing or replacing critical equipment. When they do repair equipment they’re not bringing it up to current RAGAGEP (Recognized and Generally Accepted Good Engineering Practices) standards.”
If the above sound familiar to you, take a hard look at your PSM program!
Read the full article in this link.

Adding too much chemical causes an incident

A news report mentions an incident where an orange gas cloud leaked from a manufacturing facility for making ferric sulphate. Apparently, too much nitric acid was added to a batch, resulting in a violent reaction that produced excess amounts of nitrogen dioxide that escaped from the reactor into the air.Nitrogen dioxide is a reddish brown gas and is highly toxic if inhaled and is also corrosive.
Ensure that you have proper controls over addition of chemicals, especially if adding an excess of one chemical can trigger something unwanted. Engineering controls are the best to avoid such mishaps. Depending only on an SOP in such situations may cause an an incident to happen.
Read the article in this link.

Boiler burst kills 4

A boiler of a dyeing unit  burst on Tuesday, killing four persons and injuring 20 others on Tuesday. Inquiries are on to find out the reason for the blast. An official said that the safety valve failed release in time, leading to pressure building up inside the boiler.Read about it 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.

Explosion in sulphuric acid tank

An explosion in a sulphuric acid tank has injured four personnel in Japan. There is the danger of presence of hydrogen in sulphuric acid tanks and when you do hot work be aware of the simple precautions like gas testing etc.
Read about the accident in this link. The Chemical Safety Board had earlier brought out a safety bulletin on the Dangers of Hot work, which is worth reading for every plant operation, maintenance and safety personnel. Read it in this link.

Fire in Pharma Plant

A fire in the vacuum dryer area of a pharma plant has reportedly seriously injured three people. As per Company press release, it states "There was a fire incident in a powder processing area at early hours on Nov 28,2011, at unit 11 which is located at Pydibhimavaram, Srikakulam near Vizag, A.P. Three persons were injured and they were taken to the hospital. The powder processing area is isolated from the intermediate block. There was no impact to the operations as well as to the assets".
Another news report indicates that the fire was caused by an explosion due to high pressure in the vacuum dryer.
Read the news reports in these links
Link 1
Link 2
Link 3

Remembering Bhopal............

Please spend December 2nd/3rd as “Process Safety Day” in your organisation. Educate your personnel on the Bhopal Gas tragedy and its lessons. 27 years ago, on the night on December 2nd/3rd, 1984, on a wintry night in Bhopal, thousands of men, women and children died an excruciating death when MIC leaked from the Union Carbide factory. The survivors and the next generation children born to those exposed to the gas still are suffering from the effects of the gas. Bhopal is an ongoing tragedy and should never be forgotten. The Bhopal gas disaster comprises actually of three disasters - the first was the actual incident, the second was the inadequate compensation received and the third is the ongoing legacy of genetic defects and effects of the hazardous waste that has seeped into the ground water. Every plant operating, maintenance and safety personnel must never forget the lessons of Bhopal. 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

As you are aware, this blog is also dedicated to the surviving victims of Bhopal and for my regular subscribers, I appeal to you to buy my book "Practical Process Safety Management", the proceeds from which are donated to the surviving victims of Bhopal.Contact me at bkprism@gmail.com for buying the book.

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.

Witness to a catastrophic near miss!

On 29.11.1984, I was working  in an ammonia plant when a cylcone hit the place. Management had taken advance action and instructed us to shut off the back end of ammonia plant (the back end of the ammonia plant involves high pressures). We had shut down the back end and were waiting for the cyclone to hit us. The wind speeds were very high and all of us were taking shelter in the control room. A complaint then came in from the  another plant that was located within the same complex, that they were experiencing severe ammonia odour.  Thinking that the pilot burners of the ammonia derrick supported flare that was provided for emergency venting of the ammonia storage tank was put off by the high winds, I requested operators to go out and check them. Three operators had to go, holding each other tightly,as the wind speed was so high and could blow a man off his feet. After a short while they came back and reported that the flare was missing. I went out to check with another team and we found to our horror that the flare structure had collapsed on the main ammonia vapor line coming from the tank. The derrick structure was weak and could not bear the brunt of the wind speeds, but the main flare gas pipe was in good condition and when the derrick toppled, the main gas pipe prevented it from falling all of a sudden. Instead it fell slowly and came to rest on the ammonia vapor line! The 8" main ammonia vapour line from the tank was dented, but did not leak.
When you conduct your asset integrity program, pay attention to structures. Nowadays, in many plants, painting schedules are taking a back seat, with the net result that corrosion creeps in. Corrosion is a silent killer. It will hit you one day if you don't maintain your assets.
Interestingly, recently I read an article where a complete flare structure repair was done with minimum downtime in a plant.Read the article in this link.

Escaping from steam

Many of you will be working with steam. During startups the possibility of water hammer in a steam pipeline has the potential to rupture the line or flange joints. Your SOPs must warn operators about the dangers of water hammer. An article mentions that the best way to escape from a closed space in which a steam leak has been triggered due to water hammer is to escape in the direction in which the steam is leaking through an exit. Read this article in this link

Heat transfer fluids

Paratherm have brought out a good booklet on heat transfer fluids - do's. dont's and best practices. Some of the points brought out are:
"If any hydrocarbon liquid (oil, grease, heat transfer fluid, hydraulic fluid) is allowed to enter porous insulation, it will begin to oxidize, raising the insulation’s internal temperature. If this temperature exceeds the fluid’s autoignition temperature, the fluid is likely to spontaneously combust into a smoldering fire. Thoroughly inspect all insulation for signs of wetness and other damage.Although “hydro” testing is a commonly accepted practice with heat transfer systems,alternatives such as pressure-testing with inert gas or with the heat transfer fluid itself should be considered. Water in a system can cause pump cavitation and corrosion and, if trapped in a “dead leg” and hit by high-temperature oil, can flash to steam and literally blow the pipe or tubing apart. And if the pipe doesn’t burst, the expansion can push a slug of hot oil out the expansion tank’s vent—a serious safety hazard".
Read the complete article in this link.

Blast in melamine plant kills 14

A BBC news report indicates that 14 people were killed in a blast in a melamine plant in China when work was going on an heat exchanger. Read the news report in this link. The cause of the explosion is not known.
The European agency for safety and health and work reports an incident in 2003, in Netherlands, where three maintenance workers were killed when a gas oven in a melamine plant exploded and the three workers who were standing on the cover of the oven fell into it.The gas oven was fired by natural gas and off gases from neighbouring plants. The off gases were contaminated and were filtered before use. The filters had to be cleaned regularly. A short cut taken during maintenance of these filters created a combustible mixture of gas and air in the oven which was ignited by a stray spark. Although this was the immediate cause of the explosion, investigations concluded that the underlying cause was a company culture which had allowed the untested short cut procedure to be used.
The lesson is to follow safe procedures and not to take short cuts even under time pressure. The accident also highlights the importance of the safety culture. Read the report in this link.

Chlorine leak in paper mill

Thanks to Abhay Gujjar for sending information about a chlorine leak from a chlorine dioxide storage tank in a paper mill. Four people are reported taken to hospital.
TAPPI, the leading association for the worldwide pulp, paper, packaging and converting industries has published a booklet on safe handling and storage of Chlorine dioxide. The following points are mentioned:
Chlorine dioxide gas is unstable and readily decomposes to chlorine and oxygen under upset conditions
Chlorine dioxide decomposition is a propagating reaction similar to a combustion front or flame. Providing a sweep of fresh air across the vapor space of a storage tank has shown to reduce the probability and violence of decomposition.
Read the complete guidelines in this link. 
Read about the incident in this link.

Bio Fuels and Process Safety - Ethanol Tanks

The bio fuel industry is growing at a rapid pace. However, from a process safety point of view, it is hazardous as it deals with flammable chemicals like ethanol.  An article mentions the following:
"Steel tanks containing fuel-grade ethanol develop leaks due to stress corrosion cracking, says Oliver Moghissi, president of the National Association of Corrosion Engineers. Corrosion can be an issue near vents and any external appurtenances exposed to air, allowing ethanol to pick up moisture. Storing hydrous ethanol can produce even more corrosion due to higher water content.
There are a number of corrosion mitigation strategies, he adds, drawing on technical input from Narasi Sridhar, vice president of DNV USA, a classification society, and a fellow member of NACE. Galvanic sacrificial coatings, such as zinc or aluminum, will protect steel tanks containing ethanol. The main limitation to this system of corrosion mitigation is that it could have a negative effect on product quality. “Any dissolved metal species in the ethanol can render the ethanol unacceptable to the automotive industry, its main customer,” he tells EPM. “Any galvanic coating therefore must be tested rigorously by the end-user, the automotive community, which can be time consuming and expensive.”
Cathodic protection, however, doesn’t work for the insides of metal structures containing ethanol, the corrosion engineers add. The fuel has low electrical conductivity when compared to water and, as a result, much of the applied voltage is insulated from the metal needing to be protected. “Therefore, impressed or sacrificial cathodic protection systems will not work in ethanol,” Moghissi says. “In ethanol-gasoline mixtures, the situation is even worse since gasoline has a lower electrical conductivity than ethanol.”Read the full article in this link. 

Vacuum - a deadly killer

A news article mentions that a man was sucked into a huge duct conducting gaseous silicic acid that led to his death. The duct was about three feet in diameter. Besides inhaling the gas, he had also suffered injuries on the head while being sucked in. Another employee was also partially sucked into the duct but managed to escape with minor injuries.Read the article in this link.

Dust explosions - status of regulations in USA

An AP news article mentions the lack of regulations in the USA regarding dust explosions.
"Figures compiled by the U.S. Chemical Safety Board illustrate the scope of the problem. A 2006 study reported there were at least 281 dust explosions in the U.S. between 1980 and 2005 that killed 119 workers and injured 718. In 2007, it recommended that the Occupational Health and Safety Administration create workplace rules to control dust and cut down on explosions. The Chemical Safety Board is charged with investigating industrial accidents, but it must rely on regulatory agencies like OSHA to effect change from its findings.
"Despite the seriousness of the combustible dust problem in industry, OSHA lacks a comprehensive standard to require employers in general industry to implement the dust explosion prevention and mitigation measures," the Chemical Safety Board wrote in its 2007 report".
Read the full news article in this link.

Ammonia tank safety valve release

An ammonia tank in a plant in Australia apparently released close to 1 MT of ammonia through its safety valves due to overpressure of the tank. The plant has been ordered to close down.The Government spokesperson  correctly mentions that a safety valve is the last line of defence and this is a serious incident. Many atmospheric ammonia tanks and LPG bullets have their safety valves open to atmosphere. With rampant unauthorized residential settlements still happening around chemical industries and refineries in India, is a disaster waiting to happen?
See the video and report of the incident in this link.
Read a press release of the incident by the company in this link.

More chlorine incidents

Thanks to Mr Harbhajan Singh Seghal for sharing these incidents.

INCIDENT #1
Chlorine leakage was noticed from the valve of a chlorine tonner. They tried to control the leakage but when it became uncontrollable, they dumped the leaky tonner into the alkaline sump to neutralize the remaining chlorine. According to media, about thirty persons complained of eye irritation.
ROOT CAUSE

• 4 Nos filled chlorine tonners were stored since Dec 2008 in the open area. Out of which one toner has leaked
• Valve caps & protection domes were also not provided on these tonners.
• Minor chlorine leakage from the valve of chlorine tonner remained unattended which resulted into a major leak
• Chlorine is a dry gas .On leakage it attracts moisture from the atmosphere and increase the corrosion rate at a very high rate
• Storage in the open makes the accessories weak and further adds up to corrosion

LESSONS LEARNT

• Tonners should be stored under proper shed to protect them from direct sun light & heat.
• Valve caps & protection domes must be provided on the valves of tonners, if they are not being used.
• Regularly chlorine tonners area to be inspected for any chlorine leakage with the help of ammonia torch.
• Even if minor chlorine leakage is noticed, the same must be attended immediately and should not be left unattended.
• Filled Tonners should not be stored for more than 90 days.
• Sufficient nos of necessary PPE’s & tonner emergency handling kit should be readily available at user end.
• Periodic refresher training should be organized for employees handling chlorine tonner.
• Emergency handling procedure should be available at consumer end.

MOST IMPORTANT
Under no circumstance, leaky chlorine tonners should be dumped in alkaline water sump which may cause major mishap.
Tonner keeps floating on the surface of water and chlorine does not neutralize in the solution but spreads in the atmosphere
Chlorine attracts moisture from water and further adds to corrosion
Filler should be informed on first sight of leakage
Even the leaked tonner though empty should be made safe by washing and drying and destroy as per rules

INCIDENT #2
The Incident of bulging of filled chlorine toner occurred but there was no chlorine leakage.
INCIDENT CONTROL
The bulged tonner was immediately depressurized partly by releasing the chlorine to a 200 litre barrel having 5% dilute Caustic lye solution to reduce the pressure & temperature of the tonner and avoid its bursting. Thereafter the tonner was emptied by using the balance chlorine in their process. The emergency could be handled safely & successfully by the chlorine user.
ROOT CAUSE ANALYSIS

• Quantity of liquid chlorine was higher than the desired quantity and moreover the filled tonner was kept in the sun
• The temperature and pressure of the tonner increased due to this.
• The tonner got bulged due to high thermal expansion of liquid chlorine with temperature.

LESSONS LEARNT

• Filling of chlorine toner should be done as per filling ratio-1.19. Water capacityx1.19
• Weight of tonner should be rechechecked after filling
• Filled tonners must be stored in cool and well ventilated place
• Tonner can bulge at 45 degree centigrade with 5%excess filling.it can bulge at any time at room temperature with 10% excess filling

Electrical Safety - part of process safety

Mr Vijayraghavan shared news about an incident in Germany on 4th November when a worker died in an accident during repair work at a petrochemicals hub. The worker died as a result of an electrical shock suffered during repair work on a crane. Investigation is on to determine the cause
Schneider Electric has brought out a very good free safety video on electrical hazards . They mention that “Arc flash accidents that cause serious and sometimes fatal injuries occur five to 10 times every day in the United States. Schneider Electric has produced this electrical safety video as an awareness tool for anyone who faces a risk from electrical accidents that might occur when work is performed on energized electrical equipment. Safety standards are now in place to address the safety of workers who may be exposed to these hazards, as well as to inform employers of their responsibilities to provide employment and a place of employment which are free from recog­nized hazards that are causing or are likely to cause death or serious physical harm to his employees. This video provides information about arc flash, arc blast, shock, and electrocution hazards”.
See the low resolution video in this link
Download the high resolution video from this link and share it with all your colleagues,technicians and operators. It may prevent a fatality.

Domino effects in a disaster

A good example of domino effects of a blast occurred in July 2011 in Cyprus when munitions in a military dump located near to a power generation station blew up. The blast damaged the power station leading to severe power shortages in Cyprus. An article mentions the following:
'Twelve people have been killed and about 30 injured in a blast at a munitions dump in Cyprus. The island's largest power station has been damaged, resulting in widespread power cuts.
The force of the dawn explosions blew out virtually every window in the neighboring village of Zygi and extensively damaged the islands main power station, which remains offline.
Large-scale damage could be seen to a huge section of the barriers of the main Larnaca-Limassol highway and a huge crater about 500 meters from the power station was shown on state TV."
Read the article in this link
See pictures of the blast damage in this link.

Chlorine leak incident

Thanks to Mr Harbhajan Singh Seghal for sending this incident report:

INCIDENT OF CHLORINE LEAKAGE
Two persons were gassed in one of the chlorine consuming industry near Baroda. When the operator disconnected the tonner on the pretext of the hard valve operation of the tonner.
DETAILS OF INCIDENT 

The consumer withdraws liquid chlorine and consumes gas after evaporation.
As per practice the consumer keeps the tonner in line to withdraw maximum chlorine from the tonner.
On the specific date the operator tried to isolate the tonner at 1.0kg/cm2 pressure when about 40-50 kgs liquid chlorine was there in the tonner and ice formation was there at the bottom of the tonner.
He could not close the valve fully. The spindle of the valve damaged due to excessive force.
The operator decided to cut off the tonner by wearing SCBA.
This action resulted in heavy gas and affected two persons in the surrounding 

ROOT CAUSE OF THE PROBLEM

• Liquid chlorine withdrawal rate is 180 kgs/hr. Maximum liquid chlorine is used up in 4-5 hrs operation at this rate. Some quantity 40-50 kgs remains in the tonner at the bottom. Some consumers try to recover this as gas by keeping the tonner in line for more time This Liquid chlorine evaporates at 5-6 kgs/hr as gas and lowers the temperature of the tonner/pipe lines due to fall in pressure till the exhaust of liquid chlorine. 1.0 kg/cm2 pressure can lead to about -20 degree C and takes 8-10 hrs to become completely empty.
• Normally chlorine in the tonner is dry. But under such conditions (-20 degree) the same chlorine become wet. Water in the chlorine separates out and freezes in the sprindle of the chlorine valve. It makes the valve hard to operate at that time.
• After achievement of normal temperature chlorine evaporates first and water later. This chlorinated water reacts with the spindle and makes the chlorine spindle greenish.
• The evaporators which do not have backflow prevention system (from evaporator to chlorine tonner) results carry over of iron chloride rust to valve spindle and makes the valve hard in operation.

ACTION TAKEN

• The tonner brought to the works.
• It was depressurized and valve dismantled.
• Iron chloride rust and greenish color sludge observed in the threading of the valve.
• Damaged valve replaced with new valve.

SUGGESTED ACTION

• The tonners containing some quantity of liquid chlorine are not to be cut off at 1.0kg/cm2 till Chlorine pressure is released to neutralization system through header or evaporator.
• No Cl2 gas from the upper valve of the tonner
• No ice formation appears on tonner or pipe lines after depressurization.
• Chlorine header and evaporator must have chlorine release facility connected to neutralization system.
• Chlorine evaporator must have liquid chlorine flow control interlocked with temperature and outlet pressure to avoid the back flow of chlorine.
• Evaporator should have emergency release system with rupture disc and safety valve.
• Temperature of evaporator should be maintained between 80-85 degree C to avoid formation of rust as FeCl3 in the evaporator.
• Dry air (-40 degree) dew point is to be utilized for evaporation maintenance.
• Glass wool filter is to be utilized in gas line to avoid carry over of Fecl3 to main products and choking in chlorine system.
• Tonners can be kept in tilted position forming 20-30 degree angle to withdraw maximum liquid chlorine from the tonner.

CONCLUSION

• No chance should be taken with liquid chlorine system. Help of the filler must be taken in such cases. One volume of liquid chlorine expands to 460 times
• Chlorine neutralization system must be effective and checked from time to time.
• Single person should not take this type of emergency job.
• Always there should be two persons with safety equipment.

Taking mock drills seriously

Mock drills, if well planned, do deliver inputs where areas for improvements are needed. It is very important to follow up on the results of mock drills and act on them. An off site mock drill conducted in the US demonstrates the seriousness of the effort. In an article about the drill, it mentions that
"The drill, which began just before 9 a.m. Wednesday with the sounding of emergency sirens throughout the county, serves to ensure all emergency agencies in the county are ready in the event of a chemical emergency at the Blue Grass Army Depot, said Justine Barati, congressional liaison with the Joint Munitions Command who also works with CSEPP.A group of 28 evaluators from across the country watched the drill in Madison County, and will report on the strengths and weaknesses of the various agencies’ response, Barati said.Wednesday’s “accident” happened when two people working in the chemical area at the depot fell into some of the chemical. A third person then suffered a heart attack, Barati said. The spill involved an M55 rocket that contained GB nerve agent."
Read the report on the drill in this link.
View a video on another Homeland Security Drill where 300 zombies participated, in this link.

The importance of sight glasses in process safety