Air receiver blast

There was a blast during the cleaning of gas turbine in a polymers factory that makes cans, jars, etc. It is reported that the the valve of the gas turbine suddenly blew up that caused ripping of roof and fragments caused injury to a woman nearby. As per the news in a local news paper, due to malfunctioning of safety valve on the air receiver, the air receiver exploded. As Monday was holiday for the factory, it is reported that no injuries took place in the factory. It is luck that the person involved in the work is safe though the roof sheets blew off but did not fall on him. It is not known what precautions were taken before taking up the cleaning job, like, i) emptying the vessel and purging with inert gas and then purging with air, ii) positive isolation of all lines leading to and from the tank, iii) checking for presence of flammable concentrations in the tank, iv) checking for oxygen level, v) job hazard analysis, vi) supervision and so on.

As the work was taken up on factory holiday and incident happened, one should be careful when planning such maintenance jobs on holidays it should be ensured that safety work permit is obtained and supervision is provided.

Sharjah blast damages over 10 shops, 15 cars

Sharjah blast damages over 10 shops, 15 cars

There is a blast in a cafeteria due to gas leak from LPG gas cylinder that caused damage to 10 shops and 15 cars. We underestimate the destructive power of domestic LPG cylinders and nothing happened till now does not mean that we are safe. We have to check the condition of the cylinder, condition of the regulator and condition of the hose. We have to turn off the regulator when not in use. It is common only to close the knob on the burner instead of closing the regulator also. There were many incidents of passersby on the road getting injured/died because of fragments generated during the blast hitting them.

NDTV Video of LPG Tanker explosion

There is a video of an LPG road tanker explosion occurred in Turkey. The video was captured in a cell phone camera. It shows the impact of pressure wave generated by the explosion in the form of fall of persons, light emitted during explosion, widespread damage to property and a crater in the road.
This reminds me of an incident where an LPG tanker toppled and fell on the road. Without understanding the hazard of explosion any time, passersby gathered around. Even the company officials took more than a day to put it on the road and tow away.
In another incident an ammonia tanker fell on the road. However, in this case, the road was blocked, the company officials promptly transferred the content to another vessel and cleared the area in a few hours.

Though everyone should be careful, it is the responsibility of the transporter and the manufacturer of the chemicals to ensure that transport containers are fit for road journey, the drivers know what to do in an emergency and are trained to handle the situation. Normally, the behavior of the public at large is to gather and watch. So, the driver of the vehicle, in an emergency, should caution and drive away the public to safe distance so that they are safe in case of any eventuality.

Fatality at a Zirconium-Titanium Facility

It is reported that two persons died in a facility that handles zirconium-Titanium. Read the information from the link here. The incident occurred during packing of titanium powder into bricks. Federal Investigators Seek Cause Of Fatal Hancock Co. Blast - News Story - WTOV Steubenville. CSB in a statement stated that it is deploying 4-member investigating team. Internet search shows some accidents/injuries during the handling of pyrophoric materials, in which some useful information can be found in these links. LINK1, LINK2. 

1. Zirconium, titanium, thorium and other metal fires have great potential to cause injuries and fatalities as the thermal radiation can initiate fires in the surrounding areas. They can easily ignite and explode when subjected to friction/impact. It is well known that explosions be devastating in confined spaces. 
2. In combination with insufficient water, the metal fires can grow bigger due to release of hydrogen and can also cause sputtering leading to flying of burning splinters all around (some times to a few hundred meters distance - source: internet search) and cause secondary fires.
3. The zirconium fires are intense and bright and can cause retinal damage when viewed with naked eye. The fire once initiated can reach great heights in no time depending upon the quantity of material involved and size, when turnings are involved. It is reported extensively in literature and NFPA that metal powder/dust can cause dust explosion and friction is sufficient to initiate this.
4. TEC powder in portable extinguishers is effective only for small fires and big fires can be extinguished only by application of large quantities of water from all directions by experienced fire fighters. Further, continuous watch for at least a day is required after extinguishing as it is likely that the material under the heap can keep burning for a long time.
5. As per the safety advice mentioned in MSDS/NFPA, and as it is with any chemical, lesser the inventory, the more safer it is. We can't sit assuming that everything is safe when we are only storing and not handling / processing, which proved very costly during the famous Bhopal accident.
6. Pyrophoric materials need very little energy to catch fire / explode and it is stated that the static charge accumulated on a person is sufficient to initiate fire of this dust/powder. For a safe work place, it is recommended to use antistatic apparel, provide earthing to discharge static charge on the equipment/containers, flameproof/explosion proof electrical fittings, maintain at least 60% humidity, etc in the work area.
7. The powder generated should be incinerated every shift / day (depending upon the quantity) under controlled conditions so that the material can be rendered safe and can be disposed off as landfill.

No accidents implies everything safe or something is wrong?

No accidents – Whether everything is in control or something is not identified?


It is reported that the BP’s Deepwater Horizon rig explosion (11 deaths, 115 survivors) caused by escape of gas and oil from the well dug was preceded by seven years of work without any injury. The drilling was done and the well is to be closed. Another rig will takeover for production from the well. While BP managers assembled to congratulate the team for working without any injury, the pressurized gas gushed from the 5 km deep well and exploded.

The incident is not without early warning signs. The rubber gasket (seal to close the drill pipe tightly and shut the well) of the blowout preventer (BOP) located near the seabed, for the well got ruptured in an incident and rubber pieces were found in the mud used for holding the gas and oil within the well. A crewman accidentally forced the drill pipe by 15 ft through the BOP. But, engineers failed to analyse the cause for the presence of these rubber pieces. This shows that every major accident is preceded by a number of near misses and minor accidents. We should be able to identify, report and analyze all near misses and minor incidents however negligible they are. It appears there is pressure on the crew to complete the drilling work fast as they are already behind the schedule. This might have caused the crew to do away with the repair of critical safety systems too.

Further, the backup control system called ‘pod’ for BOP lost some of its functions. This reminds us of Murphy’s law.

The emergency drill carried out every Sunday to escape after head count was not followed after the accident. People started leaving in the available lifeboats without looking for others on the rig. This shows that whatever drills we do will go haywire and those in possession of escape vehicles will disappear instead of carrying the persons for which vehicles are intended.

It appears that safety is ignored because of the short term profits seen by the management compared to possible losses that may accrue to the organization when run without safety systems in place. The management that is responsible for allowing safety violations may not be there as they may take bonuses and leave. Once a system is violated and is in place for sometime, this wrong practice itself becomes an established system and will be considered normal. This has happened in Bhopal accident. All safety systems for MIC tanks were removed to save running costs. As there were no incidents, the management thought that they have done a wonderful job and reduced operating costs. May be, they are under pressure to show profits so that investors will be happy. Accidents do take place because public memory is short. They may be losers only for a short term and reaping increased valuation of their shares. Those affected because of the accident are limited in number and their voice is lost in the herd (of investors).

Normally when people are happy having achieved certain safety record, it will be followed with a major accident. There is no accident because we are lucky till the accident occurs. We are overconfident of our performance. We ignore the warning signals saying that everything is under control. We venture out to do something adventurous. Those who protest about violations are treated as ‘nuts’ and ‘pessimistic’. They may questioned about their integrity, commitment and chided for accepting bonuses or rise in salaries when systems are wrong as pointed out by the same persons. These persons will be blamed in all respected for pointing the violations forcing them to leave or they will be fired.

When accident occurs, people will conveniently forget everything though cautioned by few and term it as ‘one of those rare accidents which no one expected’.

LPG GAS leak, explosion and burns

Many times it is reported in news papers that there was LPG stove explosion leading to burns / deaths. Not many people are clear whether it is the explosion of stove or cylinder or gas. Normally, the leaking gas creates flammable atmospheres and when someone tries to switch on the light in the morning or uses lighter, the leaking gas in flammable range ignites and explodes. Bursting of cylinder is a rare case which can happen only when the cylinder is exposed to external fire and contents inside are pressurised and then the cylinder explodes with fragments flying all around.

Few years back, it is reported that a fragment from such explosion killed a person on the road. Otherwise, the gas explosion causes burn injuries and deaths to occupants of the building, causes collapse of the roof, shatters window panes, doors, etc.

Simple precautions like closing the regulator after use every time, keeping constant vigil / observation when milk or other items are kept on the stove, changing the hose once in two years or as recommended by the hose manufacturer will keep safe our homes and save us from consequences.

Similar to the above, auto rikshaw drivers check the level of petrol / diesel in the tank in the darkness with the help of a lighted match stick and the vapour in the tank catches fire leading severe burns. Such news reports also appear now and then in the news papers.

Such incidents as above show that people lack even common sense and it is a big question mark about how governments, regulators, society can protect them. Because such acts not only injure these silly people but also affect nearby persons and may cause destruction to persons / property located even 50-100 m away.

Spark arrestors for vehicles entering flammable areas

Last week, when I was driving my motor cycle, I heard bursting soundings most possibly from my bike. Initially, I looked around other vehicles but as I did not see anything unusual, I thought that the sound is from my bike exhaust. Earlier also I saw similar bursting sounds from other vehicles exhaust pipe along with short duration flame.

Imagine if vehicles like fire tender or ambulance with such exhaust enter flammable areas. Instead of saving the property or rescuing the persons, the sparks from these vehicles can initiate fire and explosion.

Gas cylinder Explosion

Yesterday (16.01.2009 Friday), I read a news items in a local news paper with the title, which is the title of this post. It states that four persons were seriously injured due to burns in this accident. It is reported in the news paper that when gas cylinder in use has become empty,  the house owner (a gold smith, may be with both shop and house together) informed and got refil cylinder from the LPG supplier at about 1430 hours. When the family members  of the house opened the gas (stove knob ? / cylinder cap ? / regulator knob ?), the gas leaked. Seeing this, the workers in the shop put the cylinder in a water tub. Still the leaked gas (obvious, as LPG does not dissolve in water) spread around and caught fire (there can always be an ignition source for a combustible material). The fire caused burn injuries to four persons who were working in the shop. After extinguishing the fire, the other workers admitted the injured in a private hospital and informed the police. The police went to the spot and shifted the injured to a government hospital for further treatment of the persons whose condition is serious.

The above news items and similar such news items earlier always raised so many questions in me.  A few of them are,

Whether the cylinder exploded (as per the title of the news item)

However, as per the news item mentioned below the title, it is understood that the cylinder did not explode but it is the leaked gas that exploded.

- Similarly, sometimes reports appear as gas stove explosion. This also gives impression that the stove (burners) exploded. But mostly it is the leaked gas explosion.

The reaction of the persons for arresting the leak is another question in my mind.

We can't blame the persons who have put the cylinder in a water tub in this case because of their knowledge / awareness. However, it is better if the gas cylinder suppliers put stickers on the cylinder containing information like, what to do in case of gas leak / leak and fire; whom to contact; the emergency contact numbers, what checks are to be done by the receiver i) when the cylinder is received (this is normally done by the supplier / delivery boy in some occasions) and also ii) during regular use; the cylinder test date and due date for next testing by the company; instructions for the user to inform with contact numbers  if receives a cylinder after expiry date / damaged condition of the cylinder,etc. Normally, this type of information is provided on the industrial gas cylinders and similar information with more details should be made available to the domestic users.

Eariler a few years ago, when I was in my office, I received a call that outside our organization a lorry (truck) with gas cylinders was stopped because of gas leak. My self with a colleague visited the spot and found that all gas cylinders were unloaded onto the road side and also observed some white powder on a few cylinders. On enquiry with the driver of the lorry, we found that as a precautionary measure, he used the portable fire extinguisher in the lorry.  This also shows the poor knowledge of the drivers of hazardous chemicals. Though he will get licence for hazardous chemical transportation and will be renewed every year, the employers should ensure that all their staff get required training and retrained again and again. Without training, they should not be engaged in transportation at all.  Sometimes, the material brought by the driver will be different from what is mentioned on HAZCHEM information on the containers. The trained driver will ensure that correct HAZCHEM stickers are displayed on the container and this will help the others on the road also, if the driver is not in a position to take proper measures. In the drivers cabin also, the tools and personal protective equipment list and location should be displayed prominently for the same reason.

Normally, the procedure in case of gas leak is take the lorry to a less inhabitated / less crowded place atleast and cordon the area by atleast 300 m around, simulatneously inform the police and their employer and wait for instructions. In case of gas leak of a domestic cylinder in a house, inform the supplier, take the cylinder outside in to a open area (not through lift), remove ignition sources in the nearby area to the extent possible and wait for the supplier to do the needful. In the news item reported above, it appears the cylinder was put in the water tub inside the house and may the confinement of the house lead to accumulation of gas and it is not able to disperse. The ignition source is obvious as it happened in the house that belongs to a goldsmith with shop in it. Goldsmith will have fire kiln  or of such arranagement for making the ornaments. Moreover, the refill was delivered at about 1430 hours and the cylinder was handled soon for replacement as per the news item. This shows that it happened during the working hours of the gold smith shop.

Had the cylinder was put in a water tub or covered with wet blanket / cloth outside, the leaked gas could have dispersed easily and cylinder will have cooling to prevent overpressurization in case of fire nearby.

The incident of gas leak happened in my house also once a few months ago. When I replaced the empty cylinder with a full cylinder and opened the regulator knob, I found gas leaking from the cylinder nozzle. I removed the knob and placed cylinder cap and it arrested the gas leak. I opened all windows ( I stay in an apartment) informed the supplier immediately about the leak. I could not get connection to the supplier as the phone line was busy (obvious as he will be getting calls for refill bookings). My wife went to the supplier's office located at about 3 - 4 km from my house. It took about 15 - 20 minutes to reach the office as the traffic was more on the roads and by the time we tried by phone and then informed personally, more than 45 minutes time elapsed. Then, the person came about 2 hours later, checked the cylinder nozzle and replaced the rubber gasket in it. 

It may be routine call for the gas suppliers but the users will be under tremendous tension. In my case gas leaked only when connected and regulator knob is opened. If it is leaking even when the cylinder cap is not removed then imagine the plight of the people. Similarly if the leak occurs on a weekend or non-working hours of the gas supplier, then getting help is also very difficult.

Though emergency numbers are listed in the telephone directory, in emergency people will be panicky and may not remember what to do. Also, the the numbers in the directory may be old. Further, telephone directories are not published by all telephone companies. If the users are having only mobile phones, then they don't have any directory. Fortunately, now phone number 108 is available to contact in case help required when there is an emergency (fire/police/ambulance). But, how many people know this information is questionable. Only learned people with an eye on what is happening in their surroundings will know. Otherwise, there are many people who don't read news papers or look around billboards / stickers pasted at important places.

If this information and other important details as mentioned in the beginning of this article are displayed on the cylinder itself, it will be help for all the users. The information should be available in English, Hindi and the local language. Pasting of the sticker by the gas cylinder delivery agency should be made mandatory. If the agency is made responsible, then the sticker with instructions in local language along with English and Hindi can be ensured. The sticker may cost 2-3  rupees. But, this will definitely help the users. If stickers are not used and only pamphlets are distributed, users may lose them and utility can'g be guaranteed.

I will put some more information on this subject in my future posts.