FIRE SAFETY

 

Fire is the most common serious hazard that one faces in a typical chemistry laboratory. While proper procedure and training can minimize the chances of an accidental fire, you must still be prepared to deal basics about fire extinguishers -- proper types, how to use them, when and when not to use them as well as the proper procedures to follow should a fire occur. This not a comprehensive guide.

 

If your clothing is on fire (and the floor is not), STOP, DROP and ROLL on the ground to extinguish the flames. If you are within a few feet of a safety shower or fire blanket, you can use these instead, but do not try to make it "just down the hall" if you are on fire. If one of your coworkers catches fire and runs down the hallway in panic, tackle them and extinguish their clothing.

 

Extinguishers will be conspicuously located and readily accessible for immediate use in the event of fire. They will be located along normal paths of travel and egress. If extinguishers intended for different classes of fire are located together, they will be noticeably marked to ensure that the proper class extinguisher selection is made when needed.

 

Basic Types of Fire Extinguishers

The two most common types of extinguishers in the chemistry laboratory are pressurized dry chemical and carbon dioxide extinguishers. In addition, you may also have a specialized Class D dry powder extinguisher for use on flammable metal fires (in a pinch, a bucket of dry sand will do, but you really should have a Class D unit if you work with flammable metals). Water-filled extinguishers are not acceptable for chemistry laboratory use. If you have a water-filled extinguisher, have it replaced immediately by contacting Supervision or you Chemical Hygiene Officer. Note: If you are not familiar with fire extinguishers and have not been trained in their use, DO NOT attempt to use them!

 

Which Type of Extinguisher for What Type of Fire?

 

Types of Fires

 

Class A - ordinary combustibles (e.g., paper, rags)

Class B -flammable/combustible liquids (e.g. gasoline)

Class C - electrical fires (e.g., breakers, equipment)

Class D - combustible metal fires (e.g., magnesium)

Types of Extinguishers

 

Pressurized Water     use Only on Class A fires

Dry Chemical             use on Class A, B or C fires

Carbon Dioxide         use on Class B or C fires

Metal/Sand                 use on Class D fires

 

Some fires may be a combination of these. Your fire extinguishers should have ABC ratings on them. These ratings will often have numbers that look something like "3-A:40-B:C". Higher numbers mean more fire fighting power. In this example, the extinguisher has a good fire fighting capacity for Class A, B and C fires.

 

Fight or Flight

Small, incipient fires can be extinguished only if you are trained to use a fire extinguisher. However, an immediate readiness to evacuate is essential. All fires, even those that have been extinguished, must be reported immediately. The following are guidelines on how to react to the discovery of a fire:

 

RACE In Case of Fire

  • R RESCUE   When you discover a fire, rescue people in immediate danger if you can do so without endangering yourself. Alert others in the immediate area.

  • A ALARM – Sound the alarm by pulling the alarm pull station nearest you and call 911 from a safe distance.

  • C CONFINE – Close all doors, windows and other openings, if it is safe to do so.

  • E EVACUATE – Evacuate the building and gather at the rally designated rally point.

REMEMBER - DO Not use the elevators!

 

PASS Use of a Fire Extinguisher

 

Fire extinguishers are not designed or intended to extinguish large fires, but if used properly, can control or extinguish a small fire. A small fire is defined as one that could start in a standard office trash can or laboratory fume hood and is in the incipient stage. When a fire or suspected fire (i.e., smoke) is discovered, the first reaction should always be to RACE. However, fire extinguishers are available and can be used provided the person is properly trained to use the extinguisher. The following are guidelines on how to use the extinguisher on a small fire:

  • P PULL the pin from the handle.

  • A AIM the nozzle at the base of the fire.

  • S SQUEEZE the handle to activate the extinguisher.

  • S SWEEP the nozzle from side to side at the base of the flame until the fire is out.

 

Watch the Animated PASS Technique