Course 601 - Essentials of Occupational Safety and Health

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Flammable and Combustible Liquids

flammable
There are two primary hazards associated with flammable and combustible liquids: explosion and fire.

Overview of the OSHA Standard

This standard applies to the handling, storage and use of flammable and combustible liquids with a flashpoint below 200 F. The flashpoint is the minimum temperature at which a liquid gives off enough vapor to form an ignitable mixture. Flammable liquids have a flashpoint below 100 degrees Fahrenheit. On the other hand, combustible liquids have flashpoints at or above 100 degrees Fahrenheit.

There are two primary hazards associated with flammable and combustible liquids: explosion and fire. In order to prevent these hazards, the OSHA Standard addresses the primary concern of design and construction, ventilation, ignition sources and storage. This module will discuss each of these issues in depth.

Flammable and combustible liquids are present in almost every workplace.
Flammable and combustible liquids are present in almost every workplace.

What are Flammable and Combustible Liquids?

Flammable and combustible liquids are, in short, liquids that can burn. They are classified, or grouped, as either flammable or combustible by their flashpoints. Basically, flammable liquids will catch on fire and burn easily under normal working temperatures. On the other hand, combustible liquids have the ability to burn at temperatures that are usually above working temperatures. Flammable and combustible liquids are present in almost every workplace. Fuels and many common products like solvents, thinners, cleaners, adhesives, paints, waxes and polishes may be flammable or combustible liquids. Everyone who works with these liquids must be aware of their hazards and how to work safely with them.

flammable liquids
At normal room temperatures, flammable liquids can give off enough vapors to form burnable mixtures with the air. As a result, they can be a serious fire hazard.

Fire or Explosion Hazards

At normal room temperatures, flammable liquids can give off enough vapors to form burnable mixtures with the air. As a result, they can be a serious fire hazard. Flammable liquid fires burn very fast. They also give off a lot of heat and often clouds of thick, black, toxic smoke.

Combustible liquids at temperatures above their flashpoint also release enough vapor to form burnable mixtures with the air. Hot combustible liquids can be as serious a fire hazard as flammable liquids.

Spray mists of flammable and combustible liquids in the air may burn at any temperature, if an ignition source is present. The vapors of flammable and combustible liquids are usually invisible. They can also be hard to detect unless special instruments are used.

Most flammable and combustible liquids flow easily. A small spill can cover a large area of workbench or floor. Burning liquids can flow under doors, down stairs and even into nearby buildings. Materials like wood, cardboard and cloth can easily absorb flammable and combustible liquids. Even after a spill has been cleaned up, a dangerous amount of liquid could still remain in surrounding materials or clothing, giving off hazardous vapors.

Ventilation

Well-designed and maintained ventilation systems remove flammable vapors from the workplace and reduce the risk of fire and health problems. The amount and type of ventilation needed to minimize the hazards of flammable and combustible liquid vapors depend on such things as the kind of job, the kind and amount of materials used, and the size and layout of the work area.

An assessment of the specific ways flammable and combustible liquids are stored, handled, used and disposed of is the best way to find out if existing ventilation controls (and other hazard control methods) are adequate.

Some workplaces may need a complete system of hoods and ducts to provide acceptable ventilation. If flammable vapors are likely to condense, the ducts should have welded joints. Other workplaces may only require a single, well-placed exhaust fan. Use non-ferrous fan blades and shrouds, and explosion-proof electrical equipment in ventilation systems for these liquids. Regular cleaning of the ventilation system will decrease the severity of any fires and will reduce the likelihood of spontaneous combustion if some self-heating material is present. Ventilation equipment used to handle solvent vapors should meet the relevant fire code requirements.

Personal Protective Equipment (PPE)

Safety glasses with side shields need to be worn when handling flammable or combustible materials.
Safety glasses with side shields need to be worn when handling flammable or combustible materials.

Skin and eye contact needs to be avoided when working near flammable or combustible liquids. Safety glasses with side shields, laboratory coats (coveralls are acceptable in shop settings) and closed-toe shoes need to be worn when handling these materials. This is only minimum protection and must be upgraded if necessary. Additional Personal Protective Equipment (PPE) such as chemical goggles, face shields, chemical aprons, and chemical resistant gloves and respiratory protection MUST be worn if there is a greater chance of chemical exposure. An emergency eyewash and safety shower should be located in all areas where flammable or combustible liquids are used. If there is skin or eye contact, then flush the affected area for at least 15 minutes and report to your employer for evaluation and treatment.

In emergencies like chemical fires and spills, act fast. Leave the area at once if you are not trained to handle the problem.
In emergencies like chemical fires and spills, act fast. Leave the area at once if you are not trained to handle the problem.

What about emergencies?

Even if employees take all the necessary precautions to protect themselves from hazardous material spills, they still need to be ready to handle emergencies safely. In emergencies like chemical fires and spills, act fast.

  • Leave the area at once if you are not trained to handle the problem or if it is clearly beyond your control.
  • Alert other people in the area of the emergency.
  • Call the fire department immediately.
  • Report the problem to the people responsible for handling emergencies where you work.
  • Obtain first aid if you have been exposed to harmful chemicals and remove all contaminated clothes. Emergency eyewash stations and safety showers should be present wherever accidental exposure to materials that can damage skin or eyes might occur.

Only specially trained people, equipped with the proper tools and protective equipment, should handle the emergency. Nobody else should go near the area until it is declared safe.

In closing, planning, training, and practicing for emergencies are important so everyone knows what they must do.

VIDEO

Instructions

Before beginning this quiz, we highly recommend you review the module material. This quiz is designed to allow you to self-check your comprehension of the module content, but only focuses on key concepts and ideas.

Read each question carefully. Select the best answer, even if more than one answer seems possible. When done, click on the "Get Quiz Answers" button. If you do not answer all the questions, you will receive an error message.

Good luck!

1. Choose the answer below that is NOT a characteristic of flammable or combustible liquids.

2. According to the text, a well-designed ventilation system will remove flammable vapors from the workplace.

3. If there is skin or eye contact with a flammable or combustible liquid, how long should you flush the affected area?

4. How should an employee handle a hazardous material spill?

5. An emergency eyewash and safety shower should be located in all areas where flammable or combustible liquids are used.


Have a great day!

Important! You will receive an "error" message unless all questions are answered.