National Fire Protection Association (NFPA) 704M

Color

Location

Meaning

blue

left

health

red

apical

flammability

yellow

right

reactivity

white

basal

special hazard

Key

Type of Possible Injury

Protective Equipment

4

• A few whiffs of vapor could cause death

• Vapor or liquid could be fatal on penetration of protective clothing

Only special protective clothing designed to protect against the specific hazard should be worn.

3

Material extremely hazardous to health

• Areas may be entered with extreme caution

• Full protective clothing, including self-contained breathing apparatus, rubber gloves, boots and bands around legs, arms and waist should be worn.

• No skin surface should be exposed.

2

Material hazardous to health

Areas may be entered freely with self-contained breathing apparatus.

1

Material only slightly hazardous to health

It may be desirable to wear self-contained breathing apparatus.

0

Material which on exposure to fire conditions would offer no health hazard beyond that of ordinary combustible material.

Key

Susceptibility of Material to Burning

Fire Fighting Response

4

• Very flammable gases

• Very flammable liquids

• Materials that in the form of dusts or mists readily form explosive mixtures when dispersed in air

• Shut off flow of gas or liquid and keep cooling water streams on exposed tanks or containers.

• Use water spray carefully in the vicinity of dusts so as not to create dust clouds.

3

• Liquids which can be ignited under almost all normal temperature conditions.

• Solids which form coarse dusts, solids in shredded or fibrous forms that create flash fires, solids that burn rapidly, usually because they contain their own oxygen.

• Any material that ignites spontaneously at normal temperatures in air.

• Water may be ineffective on these liquids because of their low flash points.

2

• Liquids which must be moderately heated before ignition will occur.

• Solids that readily give off flammable vapor.

Water spray may be used to extinguish the fire because the material can be cooled to below its flash point.

1

Material that must be preheated before ignition can occur.

• Water may cause frothing of liquid if it gets below the surface of the liquid and turns to steam.

• Water spray gently applied to surface will cause a frothing which will extinguish the fire

0

Material that will not burn

None

Key

Susceptibility to release of energy

Includes

Response

4

Materials which in themselves are readily capable of detonation or of explosive decomposition or explosive reaction at normal temperatures and pressures.

Materials which are sensitive to mechanical or localized thermal shock.

If a chemical with this hazard rating is in an advanced or massive fire, the area should be evacuated.

3

Materials which in themselves are capable of detonation or of explosive decomposition or of explosive reaction but which require a strong initiating source or which must be heated under confinement before initiation.

Materials which are sensitive to thermal or mechanical shock at elevated temperatures and pressures or which react explosively with water without requiring heat or confinement.

Fire fighting should be done from an explosion resistant location.

2

Materials which in themselves are normally unstable and readily undergo violent chemical change but do not detonate

• Materials which can undergo chemical change with rapid release of energy at normal temperatures and pressures

• Materials which can undergo violent chemical change at elevated temperatures and pressure

• Materials which may react violently with water or which may form potentially explosive mixtures with water

In advanced or massive fires, fire fighting should be done from a safe distance or from a protected location.

1

• Materials which in themselves are normally stable but which may become unstable at elevated temperatures and pressures.

• Materials which may react with water with some release of energy but not violently

Caution must be used in approaching the fire and applying water.

0

Materials which are normally stable even under fire exposure conditions and which are not reactive with water

Normal fire fighting procedures may be used

Key

Indicates

Comment

W

Possible hazard to the use of water.

Reactivity of chemical water listed under Reactivity key.

OX

Oxidizer

ACID

Acid

ALK

Alkali

COR

Corrosive

<rad>

Radioactive