An incident that occured in a gold treatment plant in Australia has lessons to be learnt for all of us in the chemical industry. In this incident, a cyanide line was being cleared of a choke using plant air. The hose was left connected to the system after the choke was cleared. As the blockage was not totally cleared, cyanide pressure went up more than the air pressure and cyanide entered the air system. Two employees were treated for cyanide poisoning.
Read about the incident in this link. .
May 29, 2011
May 27, 2011
Transportation of hazardous cargo - How ready are you?
As India's highways develop rapidly, more and more transportation of hazardous chemicals take place on our highways. Many of you will agree that there is still a lot more to do to improve the safety while transporting hazardous cargo. 35 years ago, in the US, there was an accident involving a road tanker carrying liquid ammonia, which reportedly killed 7 persons. The cause of the accident was reported to be speeding, sloshing of the partially filled tanker, and inadequately designed guard rails. The lessons learnt from that accident are still valid today. A blog post mentions the following about the reasons for the accident:
- "The truck was driving at or near 53.6 mph when it took the curve taking it from the Loop to the Southwest Freeway. We’ll probably never know why Schmidt was speeding when he exited the Loop.
- Back then, barrier systems on routes that carry hazardous materials were not capable of redirecting vehicles that transport dangerous materials. The bridge rail at that stretch of road was more equipped to contain automobiles than trucks carrying hazardous cargo.
- The ramp where the crash occurred opened in 1963.
- Schmidt, who had been employed by Transportation Co. of Texas since 1975, had driven commercial vehicles since 1969. He had left Corpus Christi between 5 and 5:30 a.m. for the Tenneco plant and had made at least 10 trips to Houston carrying liquid loads.
- It’s said that this crash led to restrictions on the transportation of hazardous cargo through Houston, but that’s not necessarily the case. According to the NTSB report, the city had been using Loop 610 as a hazardous materials route since 1970."
May 24, 2011
Blast in storage of raw materials for explosives
Times of India has reported a blast in a stores containing raw material for manufacturing explosives, in Nagpur. The reason is being investigated.. According to the article, "The blast that obliterated at AMA Industries' store in Bazargaon on Thursday morning and caused a tremor in the city, also left those in this business confused. The structure housed raw materials for making commercial explosives and did not have finished products. Experts say the thumb rule is raw materials usually would not explode unless bound into a single explosive even in case of a fire. They can burn resulting in a massive fire but not cause a blast, said industry players on condition of anonymity. "Various chemicals like ammonium nitrate, aluminium powder, sulphur when mixed in specific proportions make an explosive. However, all such chemicals stored at different places even in a single premises do not explode under normal fire. A safe distance has to be maintained for storing each of them," said an explosive maker. Aluminium powder is known to catch fire if water is sprayed on it but still a blast is not heard of, he added".
Read the article in this link
Read another article on the effect of the blast wave in this link.
Read the article in this link
Read another article on the effect of the blast wave in this link.
May 22, 2011
Mechanical seals and flushing/cooling systems
(Diagram Courtesy Flowserve) Mechanical seals need to be understood by plant operators for their proper operation. Many times, the operations and maintenance personnel are at loggerheads because many of the operation personnel do not fully understand the principles of seal flushing/cooling systems. Flowserve has a very good mechanical seal piping plan document in this link which clearly explains the functioning for various types.
Aviation safety and Chemical Process Safety- Different approaches!
I was reading a press release by the Press Information Bureau about the improvements made by the civil aviation minsitry one year after the fatal Mangalore air crash. The report mentions the following:
"A Civil Aviation Safety Advisory Council (CASAC) was formed on May 28, 2010 with the mandate to strengthen aviation safety environment through synergisation of available expertise in areas of airlines, airworthiness, operations, air navigation, aerodromes, aircraft engineering, human performance. Special invitees to the Council include FAA, ICAO Experts, IATA, Airbus, Boeing, Bombardier etc. This is an ongoing initiative under the Chairmanship of Secretary (Civil Aviation). The Council gets its technical inputs from working groups covering Operations (Fixed wing and helicopter sub-Groups), Aerodromes, Air Navigation Services, Airworthiness General Aviation and Helicopters. Based on the reassurance drive several issues in the three areas of aerodromes, operations and airworthiness came up. Immediate actions to address the deficiencies have been taken up during the past one year. Several safety related circulars have been issued and implementation ensured. These include presence of Cabin crew in cockpit in case of one pilot leaving the cockpit, Cabin Crew to interact with pilots on intercom during period of lean cockpit activity, in the event of incapacitation of PIC, copilot to take over control and in the event of PIC not responding to calls of copilot regarding ‘go around’, assertiveness by copilot to be encouraged. Regulatory provision for penal action for reporting for duty with alcohol consumption has been made. Pilots are being subjected to Breath Analyser test prior to flights. License are being suspended for three months in case of first BA positive and on second BA positive instance, the licence is cancelled.
In a move to step up the quality of training Captains, the period of Instructorship/ Examiner-ship has been restricted to 5 years with proficiency check every 2 years. Increased oversight for selection of trainers, quality of training imparted by trainers, integrity of simulator training have been introduced. Breath Analyser Test has been mandated for approval of Training Captains and Pilots with BA ‘positive’ report have been debarred from becoming Training Captains. Existing Training Captains if found BA ‘positive’ are debarred from training Captain list for three years.The process for approval of foreign pilots has been made stringent wherein background checks are being done to ensure that these pilots have accident free record. The experience requirements for the foreign pilots have been enhanced and the pilots are subjected to Proficiency Checks before approval is granted by DGCA. These pilots are being subjected to same medical standards as the Indian pilots." Read the press release in this link
While appreciating the efforts taken by the Government in improving air safety, I could not help comparing the status of process safety management in India after the Bhopal disaster, when compared to developed nations. The PSM rule which is mandatory in USA since 1992 is still not mandatory in India......
"A Civil Aviation Safety Advisory Council (CASAC) was formed on May 28, 2010 with the mandate to strengthen aviation safety environment through synergisation of available expertise in areas of airlines, airworthiness, operations, air navigation, aerodromes, aircraft engineering, human performance. Special invitees to the Council include FAA, ICAO Experts, IATA, Airbus, Boeing, Bombardier etc. This is an ongoing initiative under the Chairmanship of Secretary (Civil Aviation). The Council gets its technical inputs from working groups covering Operations (Fixed wing and helicopter sub-Groups), Aerodromes, Air Navigation Services, Airworthiness General Aviation and Helicopters. Based on the reassurance drive several issues in the three areas of aerodromes, operations and airworthiness came up. Immediate actions to address the deficiencies have been taken up during the past one year. Several safety related circulars have been issued and implementation ensured. These include presence of Cabin crew in cockpit in case of one pilot leaving the cockpit, Cabin Crew to interact with pilots on intercom during period of lean cockpit activity, in the event of incapacitation of PIC, copilot to take over control and in the event of PIC not responding to calls of copilot regarding ‘go around’, assertiveness by copilot to be encouraged. Regulatory provision for penal action for reporting for duty with alcohol consumption has been made. Pilots are being subjected to Breath Analyser test prior to flights. License are being suspended for three months in case of first BA positive and on second BA positive instance, the licence is cancelled.
In a move to step up the quality of training Captains, the period of Instructorship/ Examiner-ship has been restricted to 5 years with proficiency check every 2 years. Increased oversight for selection of trainers, quality of training imparted by trainers, integrity of simulator training have been introduced. Breath Analyser Test has been mandated for approval of Training Captains and Pilots with BA ‘positive’ report have been debarred from becoming Training Captains. Existing Training Captains if found BA ‘positive’ are debarred from training Captain list for three years.The process for approval of foreign pilots has been made stringent wherein background checks are being done to ensure that these pilots have accident free record. The experience requirements for the foreign pilots have been enhanced and the pilots are subjected to Proficiency Checks before approval is granted by DGCA. These pilots are being subjected to same medical standards as the Indian pilots." Read the press release in this link
While appreciating the efforts taken by the Government in improving air safety, I could not help comparing the status of process safety management in India after the Bhopal disaster, when compared to developed nations. The PSM rule which is mandatory in USA since 1992 is still not mandatory in India......
Magnesium dust explosion?
An I pad manufacturing facility in China has experienced a possible magnesium dust explosion injuring 16 workers. The incident is being investigated. The news article mentions the following:
"Currently, little is known about the cause of the explosion. However, reports by the local Chinese media have stated that the explosion was caused by the ignition of magnesium dust. Magnesium is a highly flammable metal that is commonly used in industrial polishing processes. As reported by CNET, magnesium is also used in the manufacture of fireworks and flares. Faulty or deficient ventilation systems at the Chengdu plant may have allowed magnesium dust to accumulate in the atmosphere. If that was the case, even a small spark would have been enough to trigger an explosion". Read the news article in this link
"Currently, little is known about the cause of the explosion. However, reports by the local Chinese media have stated that the explosion was caused by the ignition of magnesium dust. Magnesium is a highly flammable metal that is commonly used in industrial polishing processes. As reported by CNET, magnesium is also used in the manufacture of fireworks and flares. Faulty or deficient ventilation systems at the Chengdu plant may have allowed magnesium dust to accumulate in the atmosphere. If that was the case, even a small spark would have been enough to trigger an explosion". Read the news article in this link
May 21, 2011
Learn from these process incidents
The Industrial Disaster Management Information System of the Government of Gujarat has given information about 15 process incidents. Learn from these incidents as they seem to be occurring with alarming frequency in other places too. Read about the incidents in this link.
May 19, 2011
Are we prepared to tackle a major disaster?
A news item in the Hindu newspaper indicates that a mock drill that was held in Andhra Pradesh had shortcomings. The report mentions that
"During the exercise, it was found that except fire, police, revenue, medical, and civil supplies departments, the other departments did not respond to the expected level to the crisis. According to a senior official, there was zero response from the Greater Hyderabad Municipal Corporation (GHMC) stating that the accident area did not fall under their jurisdiction.
“The officials concerned failed to respond even after information was passed on to Hyderabad. Will their reaction be the same if such an accident occurs in reality?” asked an official. He also admitted that many of the district officials failed to participate in the exercise and that there was a need to check their preparednes".
If after 27 years after the Bhopal disaster, we are still not prepared, I wonder what the situation will be when an actual disaster strikes!
Read the article in this link
May 17, 2011
Design your scrubbing systems properly
Scrubbing systems are your last line of defence. Ensure that adequate redundancy is provided to ensure that the system will work properly when needed. In an incident the CSB investigated, excess chlorine vented to a scrubber where it completely depleted the active scrubbing material (caustic soda), over-chlorinating the scrubber. The resulting decomposition reaction vented chlorine vapors to the atmosphere. Hazardous emissions continued for about six hours and led to the medical evaluation of five residents and 11 police officers, and the evacuation of 1.5 square miles. Read the CSB recommendations in this link.
May 15, 2011
Failure of UPS leading to turbine bearing damage
BHEL India has a good presentation on the importance of maintaining your UPS supply. In some of the incidents mentioned, the turbine bearing temperature increased to 140 Deg C and got damaged due to failure of UPS and auxiliary oil pump not coming in line afterthe turbine tripped. All failure modes of your UPS must be studied and corrective actions implemented. A UPS is a silent watchdog and if it malfunctions when it is required, it can cause a serious process incident. See the presentation in this link.
May 14, 2011
Combustible dust hazards - the explosions continue
The CSB has concluded that combustible iron dust has caused and explosion that killed one worker. The CSB mention the following:
"The first incident occurred on January 31 as two maintenance mechanics on the overnight shift inspected a bucket elevator that had been reported to be malfunctioning due to a misaligned belt. The bucket elevator, located downstream of an annealing furnace, conveyed fine iron powder to storage bins. The two mechanics were standing alone on an elevated platform near the top of the bucket elevator, which had been shut down and was out of service until maintenance personnel could inspect it. When the bucket elevator was restarted the movement immediately lofted combustible iron dust into the air. The dust ignited and the flames engulfed the workers causing their injuries. A dust collector associated with the elevator was reported to have been out of service for the two days leading to the incident.
The second incident occurred less than two months later on March 29 when a plant engineer, who was replacing igniters on a furnace, was engulfed in combustible dust which ignited. In the course of the furnace work, he inadvertently dislodged iron dust which had accumulated on elevated surfaces near the furnace. He experienced serious burns and bruises as a result of this second event; a contractor witnessed the fireball but escaped without injury."
Read the news release in this link.
"The first incident occurred on January 31 as two maintenance mechanics on the overnight shift inspected a bucket elevator that had been reported to be malfunctioning due to a misaligned belt. The bucket elevator, located downstream of an annealing furnace, conveyed fine iron powder to storage bins. The two mechanics were standing alone on an elevated platform near the top of the bucket elevator, which had been shut down and was out of service until maintenance personnel could inspect it. When the bucket elevator was restarted the movement immediately lofted combustible iron dust into the air. The dust ignited and the flames engulfed the workers causing their injuries. A dust collector associated with the elevator was reported to have been out of service for the two days leading to the incident.
The second incident occurred less than two months later on March 29 when a plant engineer, who was replacing igniters on a furnace, was engulfed in combustible dust which ignited. In the course of the furnace work, he inadvertently dislodged iron dust which had accumulated on elevated surfaces near the furnace. He experienced serious burns and bruises as a result of this second event; a contractor witnessed the fireball but escaped without injury."
Read the news release in this link.
May 13, 2011
The importance of properly designed back ups
A very good article by Bela Liptak about the back up systems at Fukushima mentions the following:
"The earthquake destroyed the electric power supply of the plant (the connection to the grid) which by itself should not have been a serious problem, because backup diesel generators (18) were provided. It seems they failed because they were not elevated and the 18-ft waves of the tsunami reached and damaged them. The reason for their being installed at low elevation was probably both convenience and concern for their stability. The destruction of these generators could have occurred because water entered the diesel fuel tanks and sank to the bottom because water is heavier than the diesel fuel. As the engine takes its fuel supply from the bottom of the tanks, water instead of oil reached it. It is also possible that the air intakes of the engines were not elevated and ended up under water. If either or both of these conditions existed, the engine could not operate.
The secondary battery backup (19) was of no use either because it was drastically undersized. It provided only about eight hours worth of electricity, while about ten times that would have been needed to supply the electricity needed for a safe shutdown. (It should be noted here that of the 104 American reactors, 93 are provided with only four-hour battery backups). Another problem in the Fukushima plant was the lack of automatic battery recharging. This could have been provided because the plant was still generating steam at a rate of about 5% of full capacity and, therefore, some of the turbine-generators could have been kept in operation.
No other backup was provided at the Fukushima plant. This is unfortunate, because electricity itself is not essential to cool the reactors. For example, if emergency cooling water tanks were provided on the roof, would have made it possible to charge water just by gravity, and if those tanks were properly sized, the accident could have been prevented."
Read the full article in this link
"The earthquake destroyed the electric power supply of the plant (the connection to the grid) which by itself should not have been a serious problem, because backup diesel generators (18) were provided. It seems they failed because they were not elevated and the 18-ft waves of the tsunami reached and damaged them. The reason for their being installed at low elevation was probably both convenience and concern for their stability. The destruction of these generators could have occurred because water entered the diesel fuel tanks and sank to the bottom because water is heavier than the diesel fuel. As the engine takes its fuel supply from the bottom of the tanks, water instead of oil reached it. It is also possible that the air intakes of the engines were not elevated and ended up under water. If either or both of these conditions existed, the engine could not operate.
The secondary battery backup (19) was of no use either because it was drastically undersized. It provided only about eight hours worth of electricity, while about ten times that would have been needed to supply the electricity needed for a safe shutdown. (It should be noted here that of the 104 American reactors, 93 are provided with only four-hour battery backups). Another problem in the Fukushima plant was the lack of automatic battery recharging. This could have been provided because the plant was still generating steam at a rate of about 5% of full capacity and, therefore, some of the turbine-generators could have been kept in operation.
No other backup was provided at the Fukushima plant. This is unfortunate, because electricity itself is not essential to cool the reactors. For example, if emergency cooling water tanks were provided on the roof, would have made it possible to charge water just by gravity, and if those tanks were properly sized, the accident could have been prevented."
Read the full article in this link
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