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.

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.

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.

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.

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. 

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

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 18^th 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.

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!

 

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"

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.

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 file...be patient)

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.

"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.

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.

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!

The importance of 'O' rings in process safety

I read an article about the importance of secondary seals to prevent leaks. Mr Larry Bachus, in his article mentions the following:
'About half of all pumps in the maintenance shop today were pulled out of service because they were leaking or wouldn’t hold pressure. This is most likely a leaking gasket or o-ring. The o-ring is the rubber component of most pump seals and most instrumentation fittings. The o-ring controls the temperature, pressure, and chemical limits of the device. The difference between a flowmeter in alcohol service and a flowmeter in condensate service is the o-ring. It is not the stainless steel, or the strict tolerances, or the flange bolts. The difference between a mechanical seal in ammonia service and a mechanical seal in propane service is the o-ring. The people who assemble instrumentation devices and parts for the chemical process industries install o-rings that are adequate to perform the static pressure and vacuum test on the part at the factory, which is normally done with water or air. The ultimate user must verify that the factory-installed o-rings are correct for the pumped product application (take into account temperature, pressure, chemical compatibility, and shelf life)".
Read the full article in this link.

Hydrogen peroxide accident kills two

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

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

Hazards and precautions while handling sulphuric acid

Sulphuric acid is used in many chemical plants. NorFalco, as part of their "Responsible Care" commitment have published a very good reference called " Sulphuric acid handbook" which is available in this link. (it is a 3.8 MB pdf file)

Fire in pesticide unit in AP

Thanks to Abhay Gujar for sending info on a fire in a pesticide manufacturing unit in A.P. The article mentions the following: "In a major industrial mishap, two persons were charred to death in a fire and blast in a reactor of a pesticides manufacturing company at Cheruvukommupalem in Prakasam district in the wee hours of Wednesday.The fire broke out in the third production block at about 2.30 a.m in the third floor of the plant following suspected "electric short circuit", resulting in a blast in one of the four solvent distilling reactors at the Bhagiradha Chemicals & Industries Limited (BCIL), Revenue Division Officer K Naga Babu said. Four others working in the ground floor fled to safety".
Read the article in this link.

Distilleries are Dangerous!

I have visited many distilleries in sugar plants. When compared to chemical plants, the operators knowledge of process safety is limited. In one of the distilleries, the operators were not aware of the reason why the water level was being maintained at the bottom of a flare tower. As experienced people leave the organization, it becomes all the more important for management to implement a process safety management system in distilleries. An incident in a distillery which experienced a nitric acid spill and was subsequently closed is given in this link.