OSHA & NFPA Flammable Liquid Classification

The Occupational Safety and Health Administration (OSHA) classifies flammable liquids based on their flash points into different categories. The Occupational Safety and Health Administration (OSHA) classifies flammable liquids based on their flash points into different categories.  


OSHA's classification of flammable liquids is outlined in its standard 29 CFR 1910.106 - Flammable liquids. Here are the main classifications used by OSHA for flammable liquids: 

  • OSHA & NFPA Flammable Liquid Classification

    Class IA Flammable Liquids: Liquids with a flash point below 73.4°F (23°C) and a boiling point below 100°F (37.8°C).     
    Examples include acetaldehyde, ethyl ether, and pentane.   

  • Class IB Flammable Liquids: Liquids with a flash point below 73.4°F (23°C) and a boiling point at or above 100°F (37.8°C).     
    Examples include acetone, benzene, ethanol, gasoline, methanol, and toluene.                    
     
  • Class IC Flammable Liquids: Liquids with a flash point at or above 73.4°F (23°C) and below 100°F (37.8°C).     
    Examples include diethyl ether, ethyl acetate, and heptane.                     

It's crucial for employers and workers to understand OSHA's classification of flammable liquids to implement appropriate safety measures, including the use of approved containers, storage cabinets, ventilation systems, and personal protective equipment (PPE) when working with or around flammable liquids. Safety Data Sheets (SDS) provided by manufacturers also contain important information about the classification and safe handling practices of specific flammable liquids.