September 30, 2011

September 29, 2011

Diesel tankers accident

The Telegraph reports that "Fifteen tankers loaded with fuel were gutted and more than 10 lakh litres of diesel burnt when a goods train carrying them jumped tracks in Chanabana on the Bihar-Bengal border this morning.The inferno caused the tracks to melt, leading to disruption in train services on the Aluabari-NJP route.The heat from the burning fuel also scorched to death a villager, whose body was found after the flames were doused. Paddy on 500 acres along the tracks have been burnt.
The Northeast Frontier Railway (NFR) said the goods train, with 51 tankers and each of them filled with 70,000 litres of diesel from the Numaligarh Refineries Limited, was on its way to Jamshedpur from Maligaon in Assam. 
Read the report (with photos) in this link.

September 25, 2011

Molten Aluminium + water = explosion

An interesting theory by a scientist postulates that the twin tower collapse on 9/11 was cause by an aluminium water explosion. The article mentions the following:
"If my theory is correct, tonnes of aluminium ran down through the towers, where the smelt came into contact with a few hundred litres of water," Christian Simensen, a scientist at SINTEF, an independent technology research institute based in Norway, said in a statement released Wednesday.
"From other disasters and experiments carried out by the aluminium industry, we know that reactions of this sort lead to violent explosions." Given the quantities of the molten metal involved, the blasts would have been powerful enough to blow out an entire section of each building, he said.
This, in turn, would lead to the top section of each tower to fall down on the sections below.
The sheer weight of the top floors would be enough to crush the lower part of the building like a house of card, he said."The aluminium industry had reported more than 250 aluminium-water explosions since 1980," he said. Aluminium alloy, which in jet hulls also contains magnesium, melts at 660 degrees Celsius (1,220 degrees Fahrenheit). If heated to 750 C (1382 F), the alloy "becomes as liquid as water," Simensen said. This molten aluminium could then have flowed downward through staircases and gaps in the floor, causing a chemical reaction with water from sprinklers on the levels below.
The mix would immediately boost temperatures by several hundred degrees, releasing combustible hydrogen in the process. Such reactions are even more powerful in the presence of rust or other catalysts, which can boost temperatures to more than 1,500 C (2,700 F)."
Read the complete article in this link.

Chlorine leak incident

Thanks to Mr Harbhajan Singh Seghal for sending this incident: 
A company in Gujarat was manufacturing Chlorinated Paraffin Wax by feeding Cl2 from the 900 kgs toner in Heavy Normal Paraffins (HNP). On the day of the incident a contract labourer disconnected the empty tonner and took the fresh 900 kgs tonner in line. Immediately after taking it in line, gas started coming out from the fitting of the copper tube at high pressure. The valve of the header and tonner was attempted to be closed by wearing SCBA. But by the time the gas had already spread. Total of 34 person were affected including 15 person from one village Out of the 15 village persons,5 were minor including a 9 month old child. All the affected persons of area were admitted in hospital. The people were complaining about breathing problem, vomiting, & loose motion but their condition was stable.
Root Cause of the Incident:
· Weak copper tube and its fittings
· Not following the correct procedure of taking the filled tonner in line
· Non availability of Safety equipment near the site and extraordinarily long time for its use.
· Non competent person handling Cl2
· Inadequate facilities for Cl2 handling
· Lack of proper training to the operating persons
Action Required:
· Copper tube and its fitting are not to be kept in the open in the atmosphere. It is to be connected with the tonner immediately
· Copper tube should be 8mm I.D., 12mm O.D. and annealed for stress relief and tested at 19.9 kg/cm2 pressure
· Ammonia torch and safety equipments should be near the installation
· While connecting the tonner, the valve should be crack opened to check for leakage. In case of minor leakage the valve is to be closed immediately
· Provision of high capacity vacuum blower to be available at site. The blower to be started in case of heavy leakage in order to avoids spreading of gas
· The operating persons should be trained to wear the safety equipment particularly SCBA in shortest possible time
· In case of leakage beyond control on site/ off site emergency should be initiated
· Copper tube and its fittings have limited life. Life varies from plant to plant. The tube needs to be replaced before the established Avg. life.
· Leakage must be checked from the Cl2 tonners at the time of connection/ disconnection with ammonia torch by slightly cracking the valve in case of connection and slightly loosening the connection at the time of disconnection
· Regular drills should be conducted for usage of safety equipment and critical equipment need to be provided and tested at regular intervals.

September 23, 2011

Process Safety - union's perspective

The steelworkers union of USA has published an article mentioning that Oil refiners fail to learn from past safety incidents and near misses. This was published in 2009. The article mentions the following:
"OSHA is seeing the same problems repeatedly at refineries as it inspects them as part of its national emphasis inspection program. In the first year of the inspection program OSHA issued nearly 350 process safety management (PSM) citations to 14 refiners. The OSHA statement said the agency sent letters to the management of more than 100 oil refineries, providing them with data on compliance issues found under the emphasis program and urging them to comply with the (PSM) standard.
The API and industry are fighting us on the level of transparency and public reporting for process safety performance indicators.The goal of such transparency and public reporting is to allow refiners and petrochemical companies to learn from each other so accidents and catastrophic events are prevented.
This process also makes the companies more accountable to their workers and the communities where their refineries and petrochemical plants are located. It forces them to not just say they are being safety conscious, but to show they’re actually doing something about it".

Read the article in this link
UPDATE: An article published on Sept. 23rd, 2011 mentions the following:
"The lead negotiator for the United Steelworkers said the union representing employees at 69 U.S. oil refineries is prepared to strike if companies don’t agree to stricter safety procedures at plants and pipelines.
The USW, which failed during contract negotiations in 2009 to get companies to agree to have a USW-trained safety specialist at each refinery, will make a similar demand during talks that begin in January for a new three-year pact, Gary Beevers, a USW vice president, said today."
Read the article in this link.

September 21, 2011

Hydrogen Sulphide leak kills 4

In a leak at a chemical manufacturing facility in Thane, a leak of hydrogen sulphide gas has reportedly killed 4 people. Read about the incident in this link.
In a publication made in 1996, the Oil, Chemical and Atomic Workers International Union has made a simple yet effective safety bulletin on the dangers of H2S. They also list some incidents. Read it in this link.
I have investigated fatalities involving H2S, some of them involving release of H2S when an open vessel containing sludge was moved. The trapped H2S gas under the sludge was released and killed two people. Do not take it for granted.

September 20, 2011

Explosion in Chemical Factory

A news report mentions that fire and explosions in a chemical factory in Canberra made residents think that the place was being bombed! It appears that the fire and explosion was caused by transformer oil. See the news report and video in this link.

September 18, 2011

Process safety and Maintenance spends

Penny wise pound foolish. If you do not maintain your assets well, you will end up paying more in the long run. Maintaining your assets not only improves process safety, it improves reliability and morale of the plant and maintenance personnel.In these days of cost cutting and lack of competency in companies, many plant managers turn a blind eye to the deteriorating assets. This also brings me to another question - how much can you flog your equipment? By debottlenecking efforts, you may increase your capacity by 30% but have you studied the effect of running on high load on the remaining plant equipment?
Read an article by  Jim McCarty on "spend now, save later" in this link. It applies to chemical plants also.

September 17, 2011

Process safety and technology

I have always strongly felt that technology alone cannot solve your process safety problems, its your approach towards your people and your plant that will keep you safe.
An article in the Moscow Times mentions "The United States suffered only 20 aviation fatalities in 2010, according to the Aviation Safety Database. Russia suffered 110 fatalities in the same year, the bulk of which were accounted for by the Polish Tupolev-154 that crashed in foggy conditions near Smolensk in April.
While declining to comment on the situation in Russia, one U.S. aviation professional concurred that "technology does not equal safety."
"The U.S. is lagging in air traffic control — we're using 1950s equipment and ground-based radar that means we have to fly these circuitous, occasionally inefficient routes — but it is safe," said Charles Duncan, United Airlines vice president for transatlantic, Middle East and India sales, in an interview with The Moscow Times.
 "If fewer airlines meant safer skies, the world would be a much simpler place than it is," Oleg Smirnov, chairman of the Federal Transport Agency's commission on civil aviation, said in reference to government plans to slash some of Russia's hundred-plus airlines.The real problem is a misguided, laissez-faire policy of registration and approval that allows "almost anyone" to set up an airline extremely easily, Smirnov said. He also blamed a culture that promotes profits over professionalism and a blurred hierarchy of responsibility that allows companies to pressure pilots not to abort flights."
Doesn't the above sound familiar in our Chemical Industry, too? Putting profits over people and plant will not help you even if you have the latest technology. Read the full news article in this link. 

September 14, 2011

Refinery cited for PSM violations

A news item mentions that a refinery has been cited in the US for PSM violations. Included in the serious violations are "failing to investigate incidents as being related to process safety management, equipment repair, address inconsistent thickness measurements collected during pressure vessel inspections, maintain accurate and updated engineering drawings, and ensure that written operating procedures were certified as being current and accurate".
Read the article in this link

September 10, 2011

Dust explosions - Ignorance is Deadly!

A dust explosion can be deadly. The sugar dust explosion at Imperial Sugar Industries, Port Wentworth, Georgia, USA in 2008 killed 11 people and injured 42 workers, some of them critically. Dust explosions have known to occur as far back as the 18th century when a baker reported an explosion in a flour warehouse. Most organic materials and many metals will burn or explode if they are finely divided and dispersed in air and contact an ignition source. Dust explosions have occurred in a many industries including flour, coal, aluminum, plastic, vitamins, pharmaceutical compounds, sugar, tea, corn starch etc.A normal fire triangle consists of fuel, oxygen and ignition source. However for a dust explosion to occur, two additional elements are required – dispersion of the combustible dust in air in a concentration sufficient to ignite and confinement.Hence for a dust explosion to occur, the following are needed:
1. Fuel
2. Air (oxygen)
3. Ignition source
4. Dispersion of combustible dust
5. Confinement (The confinement causes and explosion to occur)
The above 5 elements needed for a dust explosion to occur are called a dust explosion pentagon.
The damage from a dust explosion is catastrophic because the primary dust explosion causes the loose dust present in beams and on top of other equipment to shake loose and fall down. This causes a secondary explosion which is far more deadly than the first one. Thus the domino effect of the primary dust explosion can be carried forward through elevators, conveyors and silos. The result is a catastrophic explosion. NFPA 654 states that dust layers 1/32 inch thick can create hazardous conditions.
The Material Safety Data Sheets for many substances do not indicate the potential for dust explosions. Many organisations implement changes that inadvertently create an atmosphere for a dust explosion. Enclosing an open conveyor is one such change. The Chemical Safety Board of the USA has recorded 197 incidents involving dust explosions since 1980, with 109 fatalities and 592 injuries.
Preventing dust explosions:
To prevent a dust explosion, it is necessary to eliminate the fuel (combustible dust), oxygen or ignition source.
While complete elimination of the fuel (combustible dust) may not be possible, it is possible to eliminate the chance of a secondary explosion by proper training and housekeeping. Dust collectors must be maintained properly to avoid a drop in their collection efficiency. Another method is to add an inert material like rock dust into the combustible dust.
Complete removal of oxygen is also not possible in a system comprising of conveyors, elevators, bins and silos. Inerting (use of an inert gas) also brings along safety issues of asphyxiation of personnel.
Eliminating all sources of ignition may also not be possible. Normal sources of ignition include the following:
  •   Hot bearings and surfaces
  •   Static electricity
  •   Hot work (welding, cutting, brazing or spark producing activity)
  •   Electrical system including faulty equipment
Mitigating dust explosions:
Effective mitigation requires properly designed engineering solutions. These solutions include explosion venting, explosion suppression and explosion isolation.
Explosion Venting
Explosion vents are designed to direct the gases from a dust explosion to a safe location and prevent over pressurization and damaging the equipment. The location of the vent should be placed in such a way as not to harm personnel.
Explosion Suppression
An explosion suppression system consists of a pressure or temperature sensor that detects the start of a dust explosion and a chemical suppression or inerting system that is automatically activated when the start of an explosion is detected. The chemical suppression or inerting system cools or extinguishes the flame front before it can cause damage.
Explosion Isolation
The explosion isolation systems work on the principle of detecting a dust explosion early and isolating long sections of pipelines leading to the protected equipment. A fast acting valve is used to isolate the protected equipment. The explosion venting systems are not suitable for dusts that burn quickly as the flame front speed will be high in such cases.

September 9, 2011

Pictures of the boiler gas explosion

Thanks to Divyang B Shah for sending pictures of the boiler gas explosion I had mentioned two posts back. Pictures always speak a thousand words!


September 8, 2011

Generation next and Process Safety

I had given a presentation on Process safety management  to the Ankleshwar Chapter of Indian Institute of Chemical Engineers recently. A large number of young engineers were present. The chapter is doing good work by exposing the young engineers to the concepts of process safety management. In the audience, there were also young mechanical engineers who were working in chemical plants. We can prevent another Bhopal only by passing on the lessons learnt from Bhopal to the younger generation. The memories of Bhopal should not die with this generation but must always be kept fresh. Read my earlier post on the "Lessons from Bhopal - more so relevant today"

September 7, 2011

Boiler explosion in Gujarat

"The Hindu" newspaper has reported a boiler explosion in a diary in Gujarat that has killed 7 and injured 21 others. Apparently a leaking gas pipeline was being repaired when the explosion occurred. In many companies, I have observed hot work allowed in many gas fired utility boilers and incinerators after the operators have just isolated the natural gas supply but not blinding it. In one case, the operators had isolated the natural gas to the burner of a utility boiler and removed the burner. Their argument was that they have disconnected the burner and hence no gas could get into the boiler. However, the open gas pipe (after the burner was removed) was pointing towards the boiler and when we tested the area around the pipe with a flammable gas detector, it was in flammable range. Do not depend on isolation valves alone to stop the gas from leaking through.
Read about the boiler explosion in this link.

September 6, 2011

Caustic Soda - process safety

As part of their Responsible Care commitment, DOW Chemicals has published a pdf file called "Caustic Soda Solution Handbook". It contains useful data that will be required on a day to day basis for storage and handling as well as transportation. Download it from this link. (large patient)

September 4, 2011

Bromine leak in Russia

The BBC reports that at least 42 people received hospital treatment in the Russian city of Chelyabinsk after a leak of the toxic chemical bromine in a rail incident. Apparently about 2000 two liter glass bottles of bromine was being transported by rail and it is estimated that about 24 to 50 liters were released. Read the report in this link See a video of the leak in this link.

September 3, 2011

"Automation Addiction" in flying and its relation to process safety

Joan Lowy of AP has written an article mentioning the following:
'Pilots' "automation addiction" has eroded their flying skills to the point that they sometimes don't know how to recover from stalls and other mid-flight problems, say pilots and safety officials. The weakened skills have contributed to hundreds of deaths in airline crashes in the last five years.
Some 51 loss of control" accidents occurred in which planes stalled in flight or got into unusual positions from which pilots were unable to recover, making it the most common type of airline accident, according to the International Air Transport Association.
"We're seeing a new breed of accident with these state-of-the art planes," said Rory Kay, an airline captain and co-chair of a Federal Aviation Administration advisory committee on pilot training. "We're forgetting how to fly."
Read the article in this link.

This has direct relations to the Chemical Process Industry. With so much automation in our idndustry, I am sure that operators are really forgetting their troubleshooting skills in the event of an emergency. Dr Trevor Kletz has always propounded that things must be kept simple and the way process control manufacturers are developing and implementing "solutions" for process safety, it leaves me dumbstruck. In another post, I had written that today I see operators who are becoming "procedural robots" during emergencies and plant upsets. This is a dangerous situation. Simulators do help in keeping operators skills up to date but management often thinks that it is a waste of money. Cluster simulation training ( for processes that have the same licensor) could be started, with companies pooling in for a common simulator training facility.

September 2, 2011

Counterfeit bearings and process safety

An interesting article about counterfeit bearings mentions how good the counterfeiters are getting. In today's competitive environment, organisations look at cutting costs. Sometimes this may lead one to purchase a lower priced product that seems to meet all specs, but can be a counterfeit. I know of cases where wrong metal plate materials have caused incidents. Make sure you have a robust positive material identification system for your incoming items.
Read the article here. Are you bearing an unnecessary risk? Randy L. Bowen, SKF USACounterfeit bearings can lead to equipment downtime and safety problems.

September 1, 2011

Earthquakes and Process Safety

The recent earthquake that hit the East coast of US has triggered a number of articles on the possibility of earthquakes in areas which are not normally earthquake prone. An article in the Economic Times mentions the following:
'Residents of the east coast of the United States generally think of themselves as safe from earthquakes. This feeling was given a jolt on August 23 when a 5.9-magnitude earthquake hit near the town Mineral in Virginia. Nobody died, but a nuclear reactor there shut down by itself as its electricity supply tripped. This nuclear plant was designed to withstand earthquakes of magnitude up to 6.2 on the Richter scale. The designers of the plant had thought that Virginia would not experience stronger earthquakes, but the tremor last week was uncomfortably close to the limit.
Central India, on the other hand, has a high degree of bulge from flexure due to stress built up from the Himalayas. Recent studies have discovered this stress as much as 1,000 km south of the Himalayas. The 1993 Latur earthquake had happened at a region of stress. This earthquake, measuring 6.4, had shocked seismologists as they had never expected an earthquake to happen there. The lessons of the recent spate of intraplate earthquakes are clear. A large portion of India lies in hazardous zones, a fact that is relevant to rapidly expanding nuclear power industry in India.
Given the ability of intraplate earthquakes to surprise, one should expect damaging earthquakes at many places in the country. Even southern cities are not entirely safe, although seismologists do not expect even moderate earthquakes to happen there. Many high-rise buildings are built without following any codes. Especially vulnerable are those on stilts and those built on or near dried lakes. The city of Bangalore is full of such buildings. So are several other cities in the country. Are we inching towards one of our worst natural disasters? "
Read the full article in this link.
A chemical plant that is not designed to the current earthquake resistance standards can be the cause of catastrophic accidents. There are large storage tanks containing highly hazardous materials in many plants and imagine the impact if their contents come out during an unanticipated earthquake!