NFPA Identification System

About NFPA
The national fire protection association (NFPA) was established in 1896 as a non-profit organization with the intention to reduce the burden of fire/explosion worldwide and other hazards on the quality of life. The NFPA advocated consensus codes and standards, research, training, and education so as to prevent fire hazards in those areas which has the maximum chance of getting fire. Today, NFPA has become the world's leading advocate of fire prevention and has great influence on public safety.

Codes and standards of NFPA

• Building and Life Safety Codes
• Electrical Engineering
• Fire Protection Applications and Chemical Engineering
• Public Fire Protection

NFPA and gases/gas plants
Right from the construction of gas plants to the production, supply and distribution of different gases for industrial, commercial and residential uses, the NFPA plays a vital role by putting forward its codes. Different gases have different flammability features. Some can be highly flammable or while others many not be. Accordingly all manufacturers and suppliers related to gas plants must be aware of the different hazard ratings and take necessary precautions related to different gases.

NFPA Hazard Identification System
The hazard identification signal by NFPA is in the shape of a diamond with a color-coded array of four numbers or letters as shown below. Such diamond symbols are seen in gas cylinders, storage tanks, trailers, bottles of chemicals, and in various other places dealing with gases and chemicals. The colors in the squares depict the nature of flammability.

Rating indices

Red (Flammability)
Implies that the material can burn. Highly dengerous.

4	Danger	Readily flammable gas or quickly vaporized and highly flammable liquid	Example: propane gas
3	Warning	Ignited under almost most ambient conditions.	eg: gasoline
2	Caution	Flammable when moderately preheated or exposed to high ambient temperature.	eg: diesel fuel oil
1	Caution	Combustible if pre heated.	eg: corn oil
0	Stable	Not combustible.	eg: water

Blue( Health Hazard)
Type of Possible Injury.

4	Danger	On short exposure itself it can lead to death or major injury. Specialized PPE required	Example: hydrogen cyanide
3	Warning	Corrosive or toxic. Can cause serious temporary or residual injury.	eg: chlorine gas
2	Warning	Harmful when inhaled or absorbed. Can cause temporary incapacitation.	eg: ammonia gas
1	Caution	Can cause irritation and minor residual injury.	eg: turpentine
0	Stable	No hazard under fire conditions	eg: peanut oil

Yellow (Instability or Reactivity )

4	Danger	Will easily and quickly detonate at normal ambient temperature and pressure conditions.	Example: hydrogen cyanide
3	Danger	Is explosive if heated under confinement or mixed with water. Requires a strong initiating source.	eg: chlorine gas
2	Warning	Material undergoes chemical change at elevated temperatures and pressures. It also reacts explosively with water .	eg: ammonia gas
1	Caution	The material is usually stable but reacts if heated or mixed with water	eg: turpentine
0	Stable	Material is normally stable, even under fire exposure conditions. It is not reactive when mixed with water	eg: peanut oil

White (Special precaution)
The fourth square in the diamond which is white in color can be represented by different symbols having variable content. In some cases the field can be left left blank if no unusual hazards are present. Some common symbols in the white diamond are :

W	Water Reactive	Displays unusual reactivity with water if water is used for fire fighting.
OX	Oxidizing Agent	Possesses oxidizing properties which increase the rate of combustion of other materials.

NFPA Hazard Ratings for few gases

Gas	Hazard Rating
Liquid Argon	3	0	0
Argon -Gas	1	0	0
Liquid Carbon Dioxide	3	0	0
Carbon Dioxide Gas	1	0	0
Liquid Nitrogen	3	0	0
Nitrogen gas	1	0	0
Liquid Oxygen	3	0	0	OX
Oxygen Gas	0	0	0	OX
Hydrogen Gas	0	4	0