Flammable And Combustible Liquid – Hazards

Flammable And Combustible Liquid

This topic “Flammable and Combustible Liquid – Hazards” will cover majorly:

  • Flammable and Combustible Liquid Hazard Classifications

  • Storage guidelines for flammable and combustible liquids
  • Usage and Handling
  • Disposal
  • Regulations and policy

We will discuss all these key area from the next paragraph.

Flammable And Combustible Liquid Hazard Classifications

National Fire Protection Association (NFPA) hazard classifications for flammable and combustible liquids are as listed below:

Flammable Liquid

Class IA – Flash Point < 73 °F (22.8 °C) & Boiling Point < 100 °F (37.8 °C). Example – Diethyl ether, pentane, ligroin, petroleum ether

Class IB – Flash Point < 73 °F (22.8 °C) & Boiling Point ≥ 100 °F (37.8°C. Example – Acetone, benzene, cyclohexane, ethanol

Class IC – Flash Point ≥ 73 ºF (22.8 ºC) & < 100 ºF (37.8 ºC). Example – P-xylenex

Combustible Liquid

Class II – Flash Point ≥ 100 °F (37.8 °C) & < 140 °F (60 °C). Example – Diesel fuel, motor oil, kerosene, cleaning solvents

Class IIIA – Flash Point ≥ 140 °F (60 °C) & < 200 °F (93 °C). Example – Paints (oil base), linseed oil, mineral oil

Class IIIB – Flash Point ≥ 200 °F (93 °C). Example – Paints (oil base), neatsfoot oil.


Storage Guidelines For Flammable And Combustible Liquids

  • Read Flammable and Combustible Liquids Overview to determine the hazard classification of your material.
  • The hazard classification of a liquid determines the type and size of container in which it may be stored.
    • Read Flammable and Combustible Liquids Container Size and Quantity Limits to find container type, size, and quantity limits for the material you store.
  • Store flammable liquids in an approved flammable storage cabinet. A variety of commercially manufactured cabinets are available.
    • Cabinets must be listed with UL1275 and labeled “Flammable – Keep Fire Away”.
    • Doors must be well fitted, self-closing and equipped with a 3-point latch kit system.
  • Select a storage container

– When flammable liquids must be stored outside a flammable storage cabinet, use approved safety cans whenever possible. They have spring-loaded lids and an internal screen which prevents combustion of the contents.

– Do not use large polypropylene (“Nalgene”) containers with stopcocks or valves at the bottom to store flammable liquids. These valves frequently leak and are unsafe in a fire.

– Never store flammable liquids in a standard or domestic refrigerator or freezer. Flammable liquids that must be chilled or frozen require specially designed “spark-proof” refrigerators or freezers.

– Cabinets no longer used for flammable liquids must be painted over so they do not indicate flammable storage.

  • Choose an appropriate location

    • Avoid storing flammable liquids on high shelves or in direct sunlight.
    • Store flammable liquids in a well ventilated area.
    • Caution: Never use environmental rooms (also called cold/ warm rooms) to store flammable, combustible, or other hazardous materials. Environmental rooms have many ignition sources and little or no outside air circulation. You can use small quantities of flammable or hazardous materials (500 ml) in these spaces, but do not store them there.
  • Transferring material

    • Transfer flammable and combustible liquids within a chemical fume hood when possible, and in a proper dispensing location such as a high hazard room (also called a flammable room). Examples of proper locations for dispensing Class I flammable liquids include:
      • Pacific Hall rooms 4014 A/B, 5014 A/B, and 6014 A/B
      • Natural Sciences Building rooms 3104C, and 4104C
      • Properly ventilated laboratory room
    • Wear appropriate PPE (i.e., Nomex® lab coat, goggles and face shield, gloves, non-synthetic clothing) when transferring material.
    • Use proper bonding and grounding techniques (see Bonding and grounding below) when transferring Class I Flammable Liquids.
    • Avoid contaminating either vessel during transfer.
  • Bonding and grounding

Class 1 Flammable Liquids must be bonded and grounded when transferring liquids in accordance with Code of Federal Regulations, 29 CFR 1910.106(e)(6)(ii):

“Grounding.” Class I liquids shall not be dispensed into containers unless the nozzle and container are electrically interconnected. Where the metallic floorplate on which the container stands while filling is electrically connected to the fill stem or where the fill stem is bonded to the container during filling operations by means of a bond wire, the provisions of this section shall be deemed to have been complied with.”

Usage And Handling

  • Label all chemical containers with the identity of the contents and associated hazard warning information.
  • When utilizing flammable liquids in the laboratory, flame retardant lab coats should be worn.
  • Flammable liquids must be handled in a fume hood, unless it is known that the permissible exposure limit (PEL) and lower explosion limit (LEL) will not be exceeded.
  • Before handling flammable liquids consider all potential sources of ignition.
  • Flammable liquid dispensing and receiving containers should be bonded together before pouring.
  • Keep flammable and combustible liquids away from strong oxidizing agents, such as chromic acid, permanganates, chlorates, perchlorates, and peroxides.
  • Large containers (such as drums) must also be grounded when used as dispensing or receiving vessels.
  • Never heat flammable liquids with an open flame.
  • Use caution when handling miscible solvent/water mixtures.
  • Treat water contaminated with water-immiscible solvents carefully.
  • When volatile materials are present, use only non-sparking explosion-proof electrical equipment such as explosion-proof refrigerators.
  • Laboratory desks and furniture should be constructed of fire-retardant materials.
  • Avoid wearing clothing made of synthetic materials while handling highly flammable materials.
  • When transporting organic solvent bottles, use secondary containers to prevent breakage and contain spills in case a bottle is dropped or strikes a surface.
  • Use only ventilated explosion proof ovens for flammable or combustible liquids, or materials that contain residual flammable or combustible liquids.
  • A spill containment kit should be available in the event of an accidental release.

Flammable And Combustible Liquid Disposal

Flammable and combustible hazardous waste must be disposed of according to local, state, and federal regulations.  OSU guidelines for disposal of flammable and combustible liquid waste are presented below.

  • It is best practice to utilize approved waste disposal cans
  • Do not use consumer goods containers (such as old milk) jugs to store waste aggregation for disposal.
  • If specialized wastes cans are not utilized, it is best to return the material to the original container and clearly label as waste.
  • Rags or paper towels soiled with flammable or combustible liquids should be segregated from common garbage. These materials should be placed in a disposal can.
  • Flammable and combustible liquid waste must be segregated
  • A Chemical Surplus Removal Request form is required before any chemical can be picked up.  Each container must be sealed and labeled with a Hazardous Chemical Surplus Tag (Form HM95-2).

Read Also5 Major ways of hazardous waste disposal

Regulations And Policy

See some regulations associated with the use of flammable and combustible liquids.

Basic Safety Precautions

  • Obtain and read all MSDS (Material safety data sheet) of materials you are using
  • Beware of all hazards involve with the material
  • Identify the substance if it is a flammable or combustible liquid
  • Eliminate the ignition source
  • Use small amount of these materials where necessary in the work area.
  • Keep storage area cool and dry
  • Use approve containers for disposal
  • Keep container close when not in use
  • Practice good house keeping and equipment maintenance
  • Wear proper personal protective equipment
  • Follow all health and Safety rules that apply to your job, etc.

Emergency Management

In an emergency situation involving the use of flammable and combustible liquid, here are some things you can do:

  • Leave the area if you are not trained to handle the situation
  • Alert other people within the area of the emergency
  • Report the situation to responsible persons that have been trained to manage such emergency
  • Obtain first aid if your have been exposed to it; you should also change the contaminated cloths.

For further details, see “Guide for flammable and combustible liquids