Blog by Mark Bridges

Battalion Chief/Hazardous Materials Specialist – Retired

What you don’t know, will hurt you! You’ve heard the phrase “high risk, low frequency”?  A new PowerPoint presentation found in Community Resources, “So Many Chemicals, So Little Time,” will help you learn more about how the decisions you make can reduce your chance of getting hurt. This information was presented at Firehouse World in San Diego in January and delivers insight into many different potential dangers and deadly situations we encounter in the fire service.

Do you know the hidden hazards in jewelry stores? Or what’s in that tank on the roof of the dry cleaners? Or why underground electrical vaults are so explosive and dangerous? How about dark chemical bottles exposed to heat and fire?

So Many Chemicals, So Little Time
Firefighters need to always be in learning mode when it comes to dealing with chemicals and hazardous materials.

Most fire department training focuses on the more common emergencies such as EMS and general fire training, including ladders, hose, pumping, etc.  We all have a good handle on that stuff, but what happens when we encounter a smoking electrical vault or some of the other less-frequent emergencies? Do we need to walk right over to the vault and stare inside it?

The short answer is, NO!  When the components and wiring of these vaults heat up, they off-gas or release Acetylene gas, which has a flammable range of 2.5 percent to 81 percent. This is the type of gas that if you look at it funny, you’ll blow up.

So what should you do? Recognize it, rescue nearby victims, cordon off the area and wait for the power company to de-energize it. Then you will consult with them and follow their guidance. Most jewelry stores use Sodium Cyanide – mix that with fire hose water and you get Hydrogen Cyanide, which is the same gas used in gas chambers.

Now, what about the chemical stored on roofs of dry cleaners? That chemical is Perchlorethylene (PERC), which decomposes to Phosgene gas when heated – similar to any chemical containing “Chlorine” or “Chlor” does.  What about the dark bottles? The reason the bottles are dangerous is because they don’t like heat or fire, which is exactly what occurs in any fire situation!  Once heated, the chemicals inside begin to decompose. Then they dry out to form a very unstable material, and can become shock sensitive, or also known to a common person as a small bomb.

These are just a few of the examples of types of things one does not routinely learn or train on. That is why it is important to seek answers and ask experts questions. In the future, consider stopping your engine or truck once in a while when you see a utility truck, or the gas company working, and ask questions – you’ll be amazed at what you learn.

 

About the Author

Mark Bridges presented “So Many Chemicals, So Little Time” during Firehouse World in San Diego in January. Bridges served as battalion chief/hazardous materials specialist with Santa Monica Fire Department in California. He is now retired and can be reached via e-mail at bridgesfsi@gmail.com.