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.

Static electricity and CO2 extinguishers

Thanks to Mr Harbhajan Singh Seghal for sending this incident:
"During the plant round of Shift Incharge at Compressor House, it was observed that there is smoke and spark on Non-Drive side bearing of Cooling Tower No.1 – Pump No.D. Immediately this pump was stopped. After stopping the pump fire took place at that place which was extinguished by CO2 Fire Extinguisher. While carbon dioxide cylinder was opened for extinguishing the fire, it was observed that there was continuous spark from the surface of the horn (Outlet Black Nozzle) of the Carbon Dioxide Cylinder. This was informed to Fire Section. As per Fire Section, this is due to static current".

A safety bulletin prepared by the safety advisory group mentions the following:
"The Safety Advisory Group, SAG, has been informed of several fatal accidents caused by explosions which occurred while using CO2 during inerting equipment and storage tanks that had previously contained flammable materials. In most cases the flammable
materials were liquids or gases but dust explosions may also be triggered by the same cause.
Examples of fatalities:
• Two navy firemen were killed in an explosion while attempting to inert an 18,9 m3 Jet Fuel tank by use of portable CO2 fire extinguisher.
• Four persons were killed in an explosion on board the tanker Alva Cape while inerting naphtha tanks using CO2 cylinders.
• Twenty nine persons were killed in an explosion while witnessing the demonstration of a newly installed CO2 fire-extinguishing system for a partially filled 5000 m3 jet fuel tank, in Bitburg, Germany.
Subsequent investigations have shown that, during the inerting process, static charges of several tens of kV were generated and accumulated at the end of the piping connected to the tank. Voltage of this nature is sufficient to produce sparks which act as points of ignition for the flammable mixtures. When liquid CO2 expands up to absolute pressures of less than approximately 5 bars, the result is the formation of small particles of solid CO2 (dry ice). As the two-phase solid/gas flows through the piping, static charges are produced by the particles rubbing against other particles, between themselves, piping and equipment. Subsequently, these charges accumulate in the zones that are not earthed/grounded at the end of the pipelines, most often in valves and nozzles. The sizes of these fields, as determined by experiments, can reach values of between 50 and 180 kV/m. Similarly, static electricity can be generated by the dry ice particles after they leave the discharge nozzle.
The pressure and impurities in the CO2, equipment materials in transfer line hoses, etc. all influence the generation of static electricity".
Read the safety bulletin in this link.

Another Chlorine leakage incident

Thanks to Mr Harbhajan Singh Seghal for sending this incident:
On 18.8.2010 a message was received from Emergency Control Room regarding chlorine leakage in one of the consumers near Vadodara. Immediately the emergency team was sent to attend the problem.
PROCESS / ACTIVITY : The consumer was filling liquid chlorine from 900 kgs to 100 kgs. Cylinders by keeping on weigh balance. The tonner (900 Kgs.cap.) was pressurized with Nitrogen from upper valve. Lower valve of the tonner was connected with the withdrawal pipe fitted with filling valve to 100 kgs. Chlorine cylinder. There was a provision to release withdrawal pipe gas in 200 ltrs. drum containing caustic 100 kgs.
CAUSE OF INCIDENT: During transferring process from 900 kgs. to 100 kgs. liquid chlorine in 900 kgs. tonner exhausted. Pressure of the tonner suddenly gone up due to nitrogen padding. This resulted in very heavy vibration in the withdrawal pipe. Due to this, connection at the both ends was disturbed and damaged the corroded fittings and filling valve due to physical impact. This resulted in heavy gas release from the tonner and cylinder side.
ACTION TAKEN :

• Both the valves of 900 kgs. tonner and 100 kgs. Cylinder were closed after wearing the SCBA (Self Contained Breathing Apparatus).
• Fire hydrant team sprayed water externally to restrict gas in the outer area.
• Police Deptt. controlled the external public for further exposure.
• 10 persons affected with gas during the process were admitted in the hospital which were discharged after first aid.
• Spilled chlorine hydrate was neutralized with Caustic Soda gradually.
• All the tonners were brought back to the plant as per the advise of Explosive Deptt. and depressurized.

All the tonners condition and valves were checked and found perfectly in working order. TECHNICAL / LEGAL LAPSES :

1. Filling of liquid chlorine from 900 kgs. to 100 kgs. was not authorized from Deptt. of Explosives.
2. 900 kgs. Tonner was pressurized manually with Nitrogen pressure from cylinder (max. pressure 150 kg/cm2).
3. Max. pressure required to transfer liquid chlorine to toner is about 10 – 11 kg/cm2 where as uncontrolled pressure was applied manually. It disturbed the transfer process due to high pressure in tonner.
4. There was no well set chlorine neutralizing system. Neutralization was done in 200 ltr. Drum containing caustic.
5. Brazing of copper tube and chlorine valve used for filling was badly corroded and brazing workman ship was very poor. The fitting was not tested at desired pressure.
6. No safety equipments were maintained by the consumer to control any emergency.

LESSONS LEARNT :

1. Filling of liquid chlorine into the tonners can be done after getting the necessary approval from the Deptt. of Explosives.
2. A well set system has to be provided for filling and neutralizing from safety point of view. It is a very unsafe process to transfer liquid chlorine without proper facilities and competent persons
3. Corroded fittings are not be used. Withdrawal pipes needs to be tested and replaced regularly.
4. Provision of pressure regulator and pressure gauge in the line / header is a must.
5. All the safety equipments and gas mask should be readily available.
6. Provision of vacuum system connected with chlorine neutralization system can help to control chlorine hydrate gas due to liquid chlorine spillage.

Electrical area classification

Many plant operations, electrical maintenance and process engineers often get confused about electrical area classification. Electrical area classification is an important part of process safety. Read a succinct explanation of electrical area classification in this link.

Process safety and security - facility siting

A news article mentions the presence of a warehouse containing ammonium nitrate near refineries and fertilizer plants in Visakhapatnam. Recently, the Govt. of India has recently brought Ammonium Nitrate under the explosives act after its usage by terrorists.
The article mentions the following:
"At the time of setting up of this facility in 2007, there was a furore. After the environment assessment report was presented before the MoEF (ministry of environment and forests), the matter went for public hearing, which saw many local residents protesting storage of this hazardous substance, backed by some political parties as well. "But like in many other cases, public objection was overlooked and the government cleared the project, which is again illegally built on the CRZ (costal regulation zone) area," said Mr Sarma.
"Vishakhapatnam is a busy and an important area," he added, "it is a major Coromandel port, it houses the headquarters of the Eastern Naval Command, is an ecologically sensitive zone and is an industrial and commercial hub. Several incidents—from the 26/11 massacre to the sinking of MV Rak—have shown us how vulnerable our coastlines are. In such a situation, storage of explosive substances like ammonium nitrate is a big risk, especially when there are no checks on it."
Read the article in this link.

The importance of lube oil

Many process incidents have been initiated by a shutdown of a critical equipment due to problems in the lube oil system. A short but good article titled "3 reasons why lube oil fails" written by Jeremy Wright highlights contamination, oil degradation and additive depletion as the 3 reasons why lube oils fail. Read the article in this link.

Hydrogen cylinder fire incident

A fire in a plant in the US where hydrogen cylinders on a trailer caught fire has been reported. See the photos of the fire in this link. Apparently a supply line was being repaired at the time of the incident.

Sodium nitrite explosion kills 2

A blast in an disinfectant manufacturing unit in China has reportedly killed two persons. The unit uses sodium nitrite. A fire is reported to have caused the explosion. The MSDS of sodium nitrite mentions the following:
"Special Remarks on Fire Hazards:
When in contact with organic matter, it will ignite by friction. May ignite combustibles.
Special Remarks on Explosion Hazards:
Explodes when heated over 1000 F (538 C). Sodium Nitrite + thiocyanate explodes on heating. A mixture of sodium nitrite and various cyanides explodes on contact. Mixture of sodium nitrite and phthalic acid or anhydride explode violently on heating.Fusion of urea with sodium nitrite Interaction of nitrites when heated with metal amidosulfates (sulfamates) may become explosively violent owing to liberation of nitrogen and steam mixed with ammonium sulfamate form. Violent explosion occurs if an ammonium salt is is melted with nitrite salt. Shock may explode nitrites. must be carried out exactly as described to avoid risk of explosion".
Read the news article in this link.
See the MSDS of sodium nitrite in this link.

Do awards and certifications help process safety management?

I have been hearing about incidents in India (some fatal) in organisations that are recognized by their peers or have been awarded certificates and awards for their safety performance. Receiving awards and logos is one thing and making a continuous 24X7 commitment to process safety is another. A friend was mentioning about an incident in an organisation in India,which has all the certifications and peer recognitions in place, where a reactor exploded killing few persons. The reaction which was highly hazardous in nature was apparently being carried out manually. During the end of the shift, the operator noticed that the reactor's steam jacket valve was passing, but apparently failed to communicate this to his relief operator. The temperature increase caused a runaway reaction to occur destroying the reactor (details about pressure relieving devices are not known) . My friend visited the unit a few months after the incident and he observed that many of the employees were not even wearing basic PPE!

I have also visited organizations in India where process safety is managed excellently and is ingrained into their way of work. What I noticed in these organizations is that most of them do not go for external recognitions but concentrate on getting their house in order on a daily basis.A good process safety management program's reward is judged by NOT having process incidents and process near misses.

Hazards of Nitrogen trichloride

Thanks to Mr Harbhajan Singh Seghal who has shared his presentation in the World Chlorine programme in Brazil last year, about the hazards of nitrogen trichloride in the chlorine manufacturing industry. Quoting from his presentation, "Nitrogen Tri-Chloride is one of the most hazardous material in Chlor-Alkali industry. Fatalities have occurred and workers have been injured by NCl3 explosions.The explosive power of small quantity of NCl3 can be catastrophic & can cause release of Chlorine & large scale damage to personnel, plant equipment . NCl3 is sensitive to light, impact and ultrasonic radiation. A spontaneous explosive compound, Explosive potential is 30% of TNT".
See his presentation in this link

Chlorine incident

Thanks to Mr Harbhajan Singh Seghal for sending this case study:
CASE STUDY OF CHLORINE LEAKAGE

 INCIDENT :

Chlorine leakage took place from the bottom of 100 Kgs. chlorine cylinder at one of the water chlorination plant situated in a populated area.
ACTION TAKEN :
- The consumer informed the FIRE BRIGADE and the manufacturer.
- Fire brigade reached the site at the earliest and the manufacturer reaches after 1.5 hr. being 100 km away. By the time situation was under control.
- Fire brigade put the leaking cylinder in the underground pit with MANHOLE.
PROBLEM EXPERIENCED IN CONTROLLING CHLORINE LEAKAGE:
- The cylinder started floating on the surface of water in the pit and gas started coming out from the MANHOLE.
- Additional weights were tied with cylinder to keep it dipped.
- Additional water had to be pumped as still some gas was coming out.
- It took about one hour to control the situation in the populated area. No body in the area was affected
OBSERVATIONS:
- The cylinder was 15 years old
- It was tested hydraulically 20 months earlier.
- Pitting & dents were observed at the bottom side near the STAND.
- Pin hole had developed in the pitting area near the welding of the stand.
- There was no safety equipment, neutralizing system with the consumer.
- No proper loading / unloading system of Cl2 cylinder was there.
- No provision of Ammonia torch / ammonia was there to check leakage during connection / disconnection stage. Corrosion was observed in the chlorination system.
POSSIBLE REASONS OF LEAKAGE:
- Some moisture in the cylinder before filling or backflow of moisture after getting the cylinder empty due to inadequate barometric leg or malfunctioning of chlorination system can result pinhole.
- Unloading of the cylinder by dumping on the ground results dent and makes the surface weak and some times develops pin hole.
- Storage of the cylinder at wet and muddy place excel rate corrosion in the cylinder surface.
- Old cylinders were designed as per Ammonia cylinders code which has tolerance of scattered porosity in the plate of the cylinder & welding against NIL porosity in the present standard IS-3196. Minor leakages were observed in such cylinders also at any time. Now, the permission is not given to such cylinders, only latest code is followed.
- Most of the consumers are withdrawing Cl2 at higher rate which results ice formation on the outer surface of the cylinder. Also gas nuisance is observed in the area due to poor connection or bad MOC particulars gaskets. In the presence of moisture & gas nuisance, chlorine cylinders and Cl2 valves are badly affected and results emergency sometime.
- Most of the consumers do not keep Ammonia Torch at site and not checking leakage at the time of connection / disconnection and on regular basis. This overlooking also causes chlorine leakage beyond control.
SUGGESTED ACTIONS :
- Cylinders are to be stored at concrete flooring under a covered shed. These should be loaded / unloaded with the help of hoist / chain block / on the plate-form to avoid any damage.
- Ammonia Torch should be kept nearby. No leakage should be allowed.Two to Three times leakage should be checked in the shift.
- Extra precautions to be taken while filling cylinder in checking moisture, physical examination of cylinder & painting etc. Cylinders with external pitting / dents should be rejected . Consumer should provide barometric leg in their system.
- Consumers need to be educated for safe handling of chlorine from time to time. Consumers should have all safety equipments, chlorine neutralizing system and competent persons.
- In case of leakage cylinder / tonner is not to be put in water. It results higher chlorine release due to poor solubility of chlorine in water and cause serious emergency. It should be handled by vacuum blower & neutralizing system only.
- At the first site leaky part of the cylinder / tonner should be brought on the upper side. This results reduction in Cl2 leakage by 15 times. By increasing the consumption rate of chlorine after above action, lowers the temperature / pressure of the cylinder and results further reduction in leak rate and gives some relief time for emergency action.
CONCLUSION :
- Cl2 leakage can be handled safely by competent persons with the help of safety equipments and chlorine neutralizing system.
- Cl2 handling system need to be audited and persons need training from time to time.
- Standard guide lines are to be followed for safe handling of chlorine.

Three killed by CO leak in steel plant

The Deccan Herald has reported an incident in a steel plant in Bellary, where three people were killed due to CO leak. The article mentions

"Three workers, including an assistant manager, died on the spot after inhaling carbon monoxide at the Jindal (JSW) steel factory at Toranagal in Bellary district early Tuesday morning.

Lack of precautionary measures is the cause of the incident, said District Superintendent of Police Dr Chandragupta, who visited the spot. A case has been registered at the Toranagal police station. The incident occurred when the trio came to the gas container at the blast furnace unit 2 of the energy management division (EMD), climbed down into the ‘U’ seal pot and turned the valve on to check the pipeline. The three men had gone to check the gas container on getting information from the control room that the gas level had slumped". Read the article in this link.

Insulation can burn!

Abhay Gujar has sent news about an insulation fire in a shoe factory in Hanoi, that killed 17 people. According to the news article, "The welder was installing a lightening rod on the factory's tin roof in preparation for a tropical storm that is expected to hit northern Vietnam later Saturday. The insulation fell to the factory floor in a fireball, blocking the 150-square-metre workshop's only entrance before quickly engulfing piles of shoemaking materials, it said".
Some insulating material can burn. Make sure you read the MSDS of your insulating material before attempting any hot work.

Handle waste with care

Waste chemicals can cause major issues if not handled properly. In 2007, an explosion took place in an waste aerosol can shredder unit in the UK An article about the incident mentions the following: "The HSE discovered that the machine had not been designed to safely shred waste containers containing residues of flammable liquids and gases. Furthermore, unsafe operating procedures were in place".
 The general human tendency when dealing with the ETP or waste handling is NOT to treat as seriously as an operating plant. With many waste treatment facilities being outsourced, make sure that you have robust systems in place to avoid incidents.

Read the article in this link.

Risks while attending to an emergency

A friend has sent details of an incident in an onshore oil well which experienced a fire. When the operations team went in a vehicle to isolate the well, they had to cross a oil spill on the track. While doing so, the vehicle caught fire and 5 personnel died.
This incident highlights the need to address all possible scenarios in your drills. No drill can be the real thing but better be prepared for the worst.

Warnings before a disaster

An article by Reuters on the Fukushima nuclear disaster highlights the fact that no accident comes without warning. There will be enough signals that an accident is about to happen but we may ignore it either out of risk blindness or pressure on production. The article highights the following about the Fukushima disaster: Cost saving culture, complaceny setting in and maintenance philosophies for older plants. All the points are applicable in the chemical industry, too.
Read the article in this link

Appeal to readers

I have been regularly writing this blog with a view to spread awareness of process safety and avoid another incident like the Bhopal gas disaster. I had already appealed to all readers to send some process incidents (short summary) which they may know so that it can be shared with everyone. Company's name need not be disclosed. I appeal again to readers to send some incidents so that it can be shared with everyone, indicating whether you want your name to be published or not. I hope my appeal draws responses this time. If you spare few minutes of your time, it would make a difference.Thank you.Write to me at bkprism@gmail.com

Incidents in Heavy Water Plant - lessons to learn

I chanced to come across an old paper by Mr Kanthiah, Mr Vaidyan and Mr Bhowmick of Heavy water plant, Tuticorin about incidents that occurred in the heavy water plant. The lessons are valid even today. The incidents discussed are:
1. Rupture of ammonia cracker tubes
2. Water entry in a cable junction box thru nitrogen line. (A nitrogen hose connected to a boiler filled with DM water allowed water to enter the nitrogen line when nitrogen supply failed)
3. Potassium amide splash on personnel due to choking of line upstream of vent wth solid potassium amide
4. Synthesis gas booster compressor trip due to malfunction of seal oil level transmitter.

Read details of the incidents in this link.

Hazardous waste tanker explosion

A news article mentions the following:
"No one was injured when a truck carrying hazardous waste exploded at a Sawyer truck stop Thursday night, but crews spent all night Thursday and all day Friday cleaning up the mess.
 The truck carrying a type of industrial waste, which was being hauled from Chicago to Canada for disposal, started to leak after the chemical reacted with something else inside the tank or parts of the tank itself.
State police Trooper Jim Janes at the Bridgman post said the waste, some type of hydroxide, was not flammable. The explosion tore apart the truck but there was no fire, he said."The tank isn't designed to carry a pressurized load. There was some type of reaction inside that tank. The pressure built up faster than the tank could handle. The liquid did not appear to be flammable, but we haven't completely identified what the material was," he said".
Read the article in this link

Table top drills for terrorism

I read an article where emergency responders in the USA conducted a table top drill for terrorist activities in an utility plant. It is always better to be prepared than regret later. Assess your security vulnerabilities (both physical and cyber) and be always prepared. Read the article in this link.

The legacy of Bhopal

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 and maintenance personnel must never forget the lessons of Bhopal. They are still relevant today. Read an article about the toxic wastes in this link.

Hydrochloric acid safety

Hydrochloric acid is used in many water treatment units attached to chemical plants. Occidental Chemical Corporation has published a Hydrochloric acid handbook, as part of its commitment to Responsible Care. The guidebook will be useful to everyone who handles and designs systems for hydrochloric acid storage, unloading and loading. Download the handbook from this link. (Pdf file...be patient)

Chemical company cited for process safety violations

A chemical company has been cited by OSHA for 11 process safety violations. They include the following
"failing to provide a written plan for employee participation, written shift change procedures, adequate process chemistry documentation, pressure relief system design and design basis, electrical classification documentation, and written mechanical integrity procedures.
Additionally, the company’s operating procedures lacked documentation of chemical properties and hazards, documentation of control measures to occur after physical and inhalation exposure to hazardous chemicals, and emergency shutdown procedures. The company also failed to ensure equipment complied with recognized and generally accepted good engineering practices, conduct compliance audits, conduct initial process hazard analysis, inspect and test equipment, and manage changes to the operating procedures before they were made".
Read the article in this link.

Cutting cost at what cost?

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

CSB Draft report on DuPont accidents - lessons to learn

The CSB has released a draft report of the three accidents at DuPont facilities. The report mentions the following: "CSB Chairman Rafael Moure-Eraso said the three accidents particularly concerned CSB personnel given DuPont’s longstanding reputation for a commitment to safety. Noting the company started as a gunpowder manufacturer in 1802, and became a major chemical producer within 100 years, Dr. Moure-Eraso said, “DuPont has had a stated focus on accident prevention since its early days. Over the years, DuPont management worked to drive the injury rate down to zero through improved safety practices.” Dr. Moure-Eraso continued, “DuPont became recognized across industry as a safety innovator and leader. We at the CSB were therefore quite surprised and alarmed to learn that DuPont had not just one but three accidents that occurred over a 33-hour period in January 2010.
CSB board member and former chairman John Bresland also spoke at the news conference: “These kinds of findings would cause us great concern in any chemical plant – but particularly in DuPont with its historically strong work and safety culture. In light of this, I would hope that DuPont officials are examining the safety culture company-wide.”
Member Bresland noted the CSB finding that the phosgene hose that burst in front of a worker was supposed to be changed out at least once a month. But the hose that failed had been in service for seven months. Furthermore, the CSB found the type of hose involved in the accident was susceptible to corrosion from phosgene. Team Lead Johnnie Banks said, “Documents obtained during the CSB investigation showed that as far back as 1987 DuPont officials realized the hazards of using the braided stainless steel hoses lined with Teflon, or PTFE. An expert employed at DuPont recommended the use of hoses lined with Monel, a strong metal alloy used in highly corrosive conditions. The DuPont official stated: ‘Admittedly, the Monel hose will cost more than its stainless counterpart. However, with proper construction and design so that stresses are minimized…useful life should be much greater than 3 months. Costs will be less in the long run and safety will also be improved.’”In fact, the Monel hose was never used. Internal DuPont documents released with the CSB draft report indicate that in the 1980’s, company officials considered increasing the safety of the area of the plant where phosgene is handled by enclosing the area and venting the enclosure through a scrubber system to destroy any toxic phosgene gas before it entered the atmosphere. However, the documents show the company calculated the benefit ratio of potential lives saved compared to the cost and decided not to make the safety improvements. A DuPont employee wrote in 1988, “It may be that in the present circumstances the business can afford $2 million for an enclosure; however, in the long run can we afford to take such action which has such a small impact on safety and yet sets a precedent for all highly toxic material activities?”
The need for an enclosure was reiterated in a 2004 process hazard analysis conducted by DuPont, but four extensions were granted by DuPont management between 2004 and 2009, and at the time of the January 2010 release, no safety enclosure or scrubber system had been constructed. CSB investigators concluded that an enclosure, scrubber system, and routine requirement for protective breathing equipment before personnel entered the enclosure would have prevented any personnel exposures or injuries.
The CSB investigation found common deficiencies in DuPont Belle plant management systems springing from all three accidents: Maintenance and inspections, alarm recognition and management, accident investigation, emergency response and communications, and hazard recognition.
CSB Team Lead Banks said, “The CSB found that each incident was preceded by an event or multiple events that triggered internal incident investigations by DuPont, which then issued recommendations and corrective actions. But this activity was not sufficient to prevent the accidents from recurring.”
The CSB draft report recommends that the DuPont Belle facility revise its near-miss reporting and investigation policy to emphasize anonymous participation by all employees so that minor problems can be addressed before they become serious. The CSB report also recommends the Belle plant ensure that its computer systems will provide effective scheduling of preventive maintenance to require, for example, that phosgene hoses get replaced on time.
The CSB draft recommends that the DuPont Corporation require all phosgene production and storage areas company-wide have secondary enclosures, mechanical ventilation systems, emergency phosgene scrubbers, and automated audible alarms, which are at a minimum consistent with the standards of the National Fire Protection Code 55 for highly toxic gases.
Industry groups have established various good practices for the safe handling of phosgene and other highly toxic materials in compressed gas cylinders. The draft report concluded that the most comprehensive guidelines are those set forth by the National Fire Protection Association, or NFPA.
The draft report recommends that industry-organizations such as the Compressed Gas Association (CGA) and the American Chemistry Council (ACC) adopt the more stringent guidelines of the NFPA for the safe handling of phosgene and other highly toxic gases.
The report recommends the Occupational Safety and Health Administration (OSHA) update its compressed gas safety standard to include modern safeguards for toxic gases such as phosgene. These improved safeguards include: Secondary enclosures for units using phosgene, mechanical ventilation systems, emergency phosgene scrubbers, and automated audible alarms".
See the press release in this link 
See a video of the animation of the phosgene incident in this link.

Thermal expansion of crude oil causes an incident

A HSE press release mentions that an incident had occurred in a crude oil pipeline due to thermal expansion of the crude oil. The report mentions that the company had recognized the risk of thermal expansion of crude oil and subsequent pressure increase but had depended on a manual system of draining the pipeline instead of installing engineering controls.
Beware of thermal expansion of liquids trapped in pipelines! Read the press release in this link.

Chemical dosing and storage systems

In many plants that I visit, I observe that many operators of chemical storage tanks and dosing systems do not follow certain basic precautions for avoiding incidents. Greg Humm of West Yost associates has a good presentation on the basic safety requirements for chemical storage and dosing systems.This is applicable for all industries including water treatment. See the presentation in this link. (PDF file - be patient!)

Managing risk in the chemical industry

With strategies of chemical companies always evolving to changing circumstances, I often find that "de-risking" strategies are often applied from a purely financial point of view rather than a combination of financial and process safety risks. In chemical industries, process safety risks need to be carefully studied and evaluated, as a single process incident could wipe out all the gains that you had obtained by de-risking purely from a financial point of view. Similarly, during mergers and acquisitions of chemical companies, process safety risks need to be carefully evaluated. It may cost you more if you do not heed process safety risks.
See BASF's approach to managing process safety risks in this link.

Operational excellence - an example

Chevron's tenets of operation is an excellent example of what process safety management should be! Their tenets, which I am quoting from this link in their website are

1. "Always operate within design and environmental limits.
2. Always operate in a safe and controlled condition.
3. Always ensure safety devices are in place and functioning.
4. Always follow safe work practices and procedures.
5. Always meet or exceed customers’ requirements.
6. Always maintain integrity of dedicated systems.
7. Always comply with all applicable rules and regulations.
8. Always address abnormal conditions.
9. Always follow written procedures for high-risk or unusual situations.
10. Always involve the right people in decisions that affect procedures and equipment".

I specially like the  last tenet. I see many companies NOT involving the right people in decisions that affect procedures and equipment.

Emergency headcounts

During a trip to Singapore, I saw an interesting LCD display outside a very large shop with many entrances and exits. This signage is posted at all entries. It warns  visitors that it is unsafe to enter when monitor turns red! (Approved load is 431).