When I was first asked to write an article on Fire Safety Standards for Spray Booths, I thought it was because someone had seen the various presentations at the coatings shows and thought they had discovered a cure for insomnia. I checked with the American Medical Association, and was informed that boring articles had been putting people to sleep since the written word originated.
If you have experienced a factory fire, or any disastrous fire, you might not find this so boring, and maybe slightly informative.
The goal of this article is not to simply go down the list of requirements in the standards. If you are involved in the finishing industry, you take the time necessary to get informed of the correct standards. These should not be seen as a restriction on your ability to produce, or a way to take your hard earned profits for some arbitrary rules.
These standards have been written in response to events that have happened, and to prevent other similar events that we know could occur. As you know, standards are subject to interpretation. Also remember that the local authority having jurisdiction may require further prevention methods. You need to know these codes to understand these interpretations, and to argue your points if necessary.
Safety is paramount to human involvement in any dangerous activity. In the finishing industry we deal with areas in factories that spray flammable coatings and produce explosive environments. These are atomized liquids or solvents, high concentrations of powders, or dusts. Should a source of ignition be introduced to this atmosphere, the potential for fire is very high.
The governing safety codes and standards are the the International Fire Code (IFC) and NFPA 33 Standard for Spray Application Using Flammable or Combustible Materials. These documents refer to other codes and standards such as the International Building Code (IBC), NFPA 101 Life Safety Code and the National Electric Code (NEC).In this article we will review information that is in NFPA 33.
To help users understand the reasons for the standard, NFPA 33 contains annex material (see NFPA 33 Annex D Fire Record)
Below are direct quotes from this section:
Leading Causes of Fire in Conventional Systems (Air Spray, HVLP, Airless,…)
- Use a spark producing equipment such as cutting, welding, and grinding near the spray area.
- Friction in most cases by overheated bearings on the exhaust fan or by rubbing of exhaust fan blades against the overspray deposits on the wall of the duct.
- Arcing electrical equipment
- Spontaneous combustion
- Discharge of static electricity
Leading Cause of Fires in Electrostatic Spray Operations
- Ungrounded or improperly grounded objects in the spray area
- Failure to fully discharge equipment before cleaning
- Pinholes leaks in the paint tubing to the spray gun
- Other causes similar to conventional systems such as smoking and cutting and welding
The two lists above are certainly good places to start. The NFPA and OSHA are concerned about safety; you and I need to be concerned also. The quality of the final finish, however, is not their concern. A good finish requires a clean area and higher air velocities than the bare minimums for safety. The velocities used in spray booths today are well above the minimums for fire safety. A good review of this was provided in Metal Finishing Magazine, “Painting Problem Solver”, February 2010 issue.
“Yeah, Yeah great! Just stand over there. No big deal.” Ten minutes later they had used everything available to put out the fire, plus running to get more. Things were scorched. But all was ok. It was interesting to hear his story because he was waving his arms and very excited. He didn’t have fun that day, and today, looks at fire safety differently.
Fire # 2
There is so much overspray inside the duct as to start and support a fire. Come on. We shouldn’t even have to talk about this one. Change you filters, clean your system. This one comes up all the time, came up during the writing of the article. It was cheaper to replace fan and duct that to clean it. You can’t use explosives to clean the duct, remember #1, explosions produce sparks.
Fire # 3
A painter smoking a cigarette and flushing solvent, from an electrostatic gun in to an ungrounded trash container. Boom! Painter only lost the hair on his arm and only almost set the building on fire. The flames reached to the truss at 40 ft in the air.
Today I can only hope he is not texting, smoking, flushing solvent, etc… You know, texting will get you in trouble these days.
I was asked by the editor to clarify this one, as I was trying to keep this entertaining I left out some details and standards. First you don’t flush solvent into the trash container (even if it was grounded, this was funny), yes even though the paper, cardboard, and wood help soak up the solvents. Yes, that’s what they told me that day.
Reality, By the Standard- Flush only into the proper containers for disposing of solvents and keep all items properly grounded. (The other funny part was texting will get you in trouble. What the funny part was, was texting is nothing compared to burning down the factory. Oh well, let’s move on.)
Fire # 4
The next painter involved with solvent, spray guns, and cleaning technique did burn down the factory. The gun was covered in solvent, flushed and atomized into the booth, and to top it off, with the power on. That’s #2 in the list of Electrostatic Systems fire causes. Nothing funny here, it took eight years for this one to work its way through the court system. The electrostatic paint gun manufacturer was found not guilty. No one was hurt but millions of dollars were lost.
Fire # 5
And last but not least. The installer of the new sprinkler system dropped a hot bit of metal from the drill bit into the lacquer dust in the dirty, dirty booth. What an exciting day. Those Firefighters really earned their money, and our respect! They were good too. They could not save the finishing shop, but they saved the rest of the building.
Those fire trucks have a nice paint job! They are our customer. Very safety conscious. This fire could have been avoided by keeping the area clean or by at least cleaning before work started. I stress these. Lets do the math. Flammable materials in the air (explosive) + dirty build up (fuel and impairment to fire extinguishers) + a spark (source if ignition) = Fire.
The above stories are true. No one was hurt. That is the only reason we can chuckle a little. But two of those losses were over $1,000,000 each.
Powder Coating is typically a safer operation. Please read below:
NFPA 33 D.1.3 – Powder Coating
- Loss experience indicates that where provisions of this standard were followed the typical fire of a powder system was confined to the powder spray pattern of the guns when the powder supplies shut off, burning stops
- Losses resulting in greater damage have occurred when the powder supply was not immediately shut off
Guess what happens when you don’t do these things? Covering up the UV Spark detector isn’t really a good idea. I am going to keep you in suspense. Read NFPA D.1.3.1 and D.1.3.2. These sections have the words; “Ignition, Fireball, Burning, and Substantial Damage.”
So understand safety, the correct standards, and the correct procedures also. Understand the reasons why these fires occur.
As stated earlier, standards are subject to interpretation. Also remember that the local authority having jurisdiction may require further prevention methods. How strict they are may depend on your past safety record and your safety record will also impact your insurance costs.
Visit the websites for the International Code Council (www.iccsafe.org) and the National Fire Protection Association (www.nfpa.org) for more information and access to the standards and codes. Follow the safety list on the equipment you have purchased, train your personnel properly, and don’t let down your guard. Here’s wishing you safe finishing!
By: Marty Powell