Incident Report

Subject:                   Ammonia Gas can deliver fire-fighters shrink wrapped!

Date of Email report:   Sun 08/01/2012

Report Detail:

Extract from SAFTENG Newsletter….

Not a year goes by where I am teaching a HAZMAT or PSM course at an ammonia facility where I am challenged on the fact that NH3 is explosive/flammable.  I stress that it takes 160,000 ppm of the gas for it to burn, but it WILL BURN when it reaches this level - all that is needed is an ignition source!  Of course the only way anyone could be in 160,000 ppm of Ammonia gas is if they are wearing a LEVEL A suit.  And this is the problem...

Too often, responders get a blind eye while in these suits, as the vast majority of chemicals responded to in this type of suit are toxic, not flammable.  Sort of like fire-fighters in their turn out gear, HAZMAT responders feel they are invincible in their LEVEL A's.  I KNOW I HAVE BEEN IN THESE SHOES ALL TOO OFTEN!  Last year I posted an article about the Borden's Ammonia Explosion in Houston, TX in December 1983.  Well less than a year later (September 1984) in Shreveport, LA a fire-fighter was killed in another ammonia gas explosion.  This FF and his partner were both donned in Level A (fully encapsulating suits) when the ammonia gas ignited.  One FF died 36 hours later from his burns and his partner survived with 3rd degree burns over 50% of his body.  Their suits ignited and melted to them as they were trying to get out of them!!!  Below are some critical points to this incident, taken from USFA and NFPA investigation report.  Emergency Responders and ammonia operators SHOULD TAKE HEED to these facts as they are presented to us from VERY RELIABLE sources:

On Monday, 9/17/1984, at approximately 4:00 p.m., an explosion occurred in a cold storage warehouse building. The explosion occurred while two members of the Shreveport FD HAZMAT Team were attempting to isolate an anhydrous ammonia leak in a section of the building refrigeration system. Employees had earlier detected the leak and workers had begun repairs earlier in the day, but were unable to complete the repair due to the effects of the ammonia.

The force of the explosion raised the building's roof assembly in the immediate area of the leak approximately one foot and severely damaged interior wall assemblies. The initial explosion also resulted in a severe fire from the ignition of ordinary combustibles in the adjacent areas of the building. The two FF's within the room of origin were severely burned when their Level A suits became ignited. One FF died within 36 hours of the explosion; the other FF was admitted to a hospital in critical condition.

Based on the investigation, the following are considered to be major contributing factors to the loss of life in this incident:

1. the ignition of a flammable mixture of anhydrous ammonia gas during the emergency scene operations
   
2. the lack of proper precautions by workers to reduce the possibility of a hazardous accumulation of anhydrous ammonia gas, and
   
3. the lack of awareness by FF's that the conditions for a hazardous accumulation of flammable anhydrous ammonia gas were present.

Other IMPORTANT facts from this incident:

1. at the time of the explosion, visibility within the room was ZEROFF's were using a non-rated forklift in their efforts to repair the leak in a room with ZERO visibility
   
2. the forklift struck a wall and curb and at that time the ammonia gas ignited
   
3. the FF's encapsulating suits were set on fire in the flash fire
   
4. the surviving FF was able to remove his burning suit and crawl through a 12" opening to escape the building, leaving behind his SCBA
   
5. the deceased FF was not able to remove his burning suit and collapsed inside the room
   
6. the ignition source was determined to be either an electrical arc from the forklift truck or a spark caused by the steel frame of the truck contacting the concrete curbing at the base of the wall assembly

Click Here (pdf) to read the entire USFA/NFPA Report.

Additional Documentation: