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Burning Love: How DOT and OSHA Regulate Flammable Materials

Posted on 2/11/2019 by Kim Folger

Last month, my colleague Joel Gregier, CDGP explored the similarities and differences between US DOT and OSHA regulations for corrosive materials. So, I thought, what better way to celebrate Valentine’s Day than to get hot and heavy with transport and safety regulations for flammable materials?
Whether you’re shopping for a last-minute gift of perfume or cologne, painting your nails or applying mascara for a hot date, or un-corking a bottle of wine to drink by candlelight, flammable and combustible materials play a major role in our celebration of this lovers’ holiday.

What Is Flammable? What Is Combustible?

 We’ve all heard of flammable chemicals and combustible materials, but what do those terms mean? Well, several agencies have differing opinions on that, and here we’ll take a look at two of them: the Occupational Safety and Health Administration (OSHA) and the US Department of Transportation (DOT). 

What Is Flash Point?

OSHA flammable liquids have a “flash point” less than or equal to 93°C (199.4°F). A material’s flash point is the lowest temperature at which an ignition source near the liquid could “flash” back and ignite the vapors.
OSHA GHS Flammable labelOSHA further divides flammable liquids into four categories of severity, based on flash point and/or initial boiling point.
  1. Flash point < 23°C (73.4°F) and initial boiling point ≤ 35°C (95°F)
  2. Flash point < 23°C (73.4°F) and initial boiling point > 35°C (95°F)
  3. Flash point ≥ 23°C (73.4°F) and ≤ 60°C (140°F)
  4. Flash point > 60°C (140°F) and ≤ 93°C (199.4°F)
OSHA also recognizes flammable solids and readily combustible solids as hazardous substances. Flammable solids are materials that may cause or contribute to a fire through friction. One example are the matches you could use to light some romantic candles. Readily combustible solids are powdered, granular, or pasty materials that easily catch fire after brief contact with an ignition source and have rapidly spreading flames.

DOT’s 49 CFR Rules for Class 3 and 4 Materials

Class 3 flammable liquid labelThe DOT defines Hazard Class 3, flammable liquid as a liquid with a flash point at or below 60°C (140°F). Some examples of flammable liquids include common solvents like acetone, many paints, and alcohols such as methanol or the kind you might use to toast your love with in a few days.  
DOT’s Hazard Class 4 is broken into three divisions, but one thing they have in commons is that they either burn or have the potential to give off flammable vapors to cause a fire.
  • Division 4.1 flammable solids include desensitized or wetted explosives, self-reactive materials, readily combustible solids, and polymerizing materials.
  • Division 4.2 are pyrophoric and self-heating materials.
  • Division 4.3 include dangerous when wet materials.
Division 4 flammable solid hazardous materials labels DOT 49 CFR

Hazmat labels from left to right: Flammable solids (Division 4.1), Spontaneously combustble (Division 4.2), Dangerous when wet (Division 4.3). 

Packing Group (PG) for Flammables 

Many hazardous materials are further classified based on how severe the hazard is. For most hazardous materials, the degree of hazard is indicated by one of three packing groups (PG) that specify the minimum strength of the packaging for shipping them. 

  • PG I = “great” danger

  • PG II = “medium” danger

  • PG III = “minor” danger

DOT has three packing group for flammable liquids based on flash and/or boiling points. PG I flammable liquids have boiling points at or below 35°C (95°F).

Class 3 combustible hazardous material labelThe DOT also regulates combustibles. Combustible liquids have flash points above 140°F and below 200°F.

Common examples of combustible liquids are many fuel oils, hydraulic fluid, and vegetable oils, including those you might use to prepare your sweetheart a Valentine’s Day feast.    

Hazards of Flammable and Combustible Materials

Regardless of whether DOT, OSHA, or both definitions apply to your operations, the two most common hazards associated with flammable and combustible materials are fires and explosions. Health hazards ranging from mild irritation and illnesses up to severe injuries or fatalities caused by asphyxiation or toxicity have also been attributed to flammable and combustible chemicals.

Thankfully, there are steps we can take to mitigate and control these hazards. And, we can follow those same rules to help us protect our hearts (and other body parts) at home too!

I'll leave you with this video to set the Valentine's mood: Elvis (Live in '73). 

Oh, and of course, "Thank you very much."

Hazmat Safety and OSHA HazCom Training

DOT and OSHA each maintain requirements for how to communicate flammability, combustibility, and other types of hazards. They also have rules for what to do in an emergency and for how to store, handle, transport, and use flammable and combustible materials safely.

Lion’s HazCom: Flammables and Combustibles Online Course may be the perfect match to help you comply with these regulations. For other common hazardous materials, make a date with another of our online OSHA/HazCom training courses by clicking here!

If you ship hazardous materials, join us for the top-rated Hazmat Ground Shipper Certification Workshop. Meet DOT's certification training requirements to prepare and offer hazmat shipments by any ground carrier. In Spring 2019, the workshop comes to Los Angeles, Denver, Las Vegas, Sacramento, Kansas City, Chicago, and more! 
Stay warm this winter and remember to keep your fires burning—but not your flammables or combustibles. From all of us at Lion, have a safe and very happy Valentine’s Day!

Tags: DOT, hazard communication, hazardous materials, hazmat shipping, osha

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