Appendix B - NFPA Label Information
NFPA 704 Hazard Rating System
National Fire Protection Association (NFPA 704)
system uses an a diamond-shaped diagram of
symbols and numbers to indicate the degree of hazard associated with a particular chemical
or material. These diamond- shaped symbols are placed on containers of chemicals or
materials to identify the degree of hazard associated with the chemical or material.
The diagram identifies three color-coded categories
of hazard for each material:
health hazard (blue
reactivity (yellow sections), and
other hazard information (white section).
Each category is divided in five levels of hazard
- zero (0) used to indicate no
special hazards and
- four (4) for severe or
extreme hazard potential.
The degrees of hazard in each of these categories are
given as follows:
Health - The degree of health hazard
of a chemical or material is based on the form or condition of the material, as well as
its inherent properties (NFPA
ratings).. The degree of health hazard of a material should indicate
the degree of personal protective equipment required for working safety with the material:
- A rating of 1 is for slightly
hazardous (toxic) material which require only minimal protection (for example,
safety glasses and gloves) in addition to normal work clothing to work with safely
- A rating of 2 is for moderately
toxic or hazardous material which require additional PPE or equipment (e.g.
chemical goggles, lab/work smock, local ventilation) in addition to that required for less
toxic material. Consult the MSDS for specific health hazard and proper PPE to use with
- A rating of 3 or 4 is for highly
to extremely toxic (deadly) material (and any carcinogen, mutagen, or teratogen).
These materials will require specialized equipment (e.g. respirator (or exhaust
hood), full face shield, rubber apron, specialized glove, handling tongs, etc) beyond
required for moderately toxic material. You must consult the MSDS and/or other safety
information to determine the hazard (acute or chronic) and the proper PPE and engineering
controls to safely use of this material.
Flammability - The flammability
hazards deal with the degree of susceptibility of the material to ignite and burn.
The form or condition of the materials, as well as their properties, affects the extent of
the hazard. Many hazardous materials such as acetone and gasoline, have a flash
point (ignition temperature) far below freezing and will readily ignite with a spark if
the vapor concentration is sufficient. A low rating of 1 is for material
with a flash point above 200F while more hazardous ratings of 2,
3, and 4 are for materials with respective flash point below 200, 100 and
73 F. (NFPA
Reactivity - The reactivity hazards
deal with the potential of a material or chemical to release energy. Some materials
are capable of rapid release of energy without any catalyst, while others can undergo
violent eruptive or explosive reactions if they come in contact with water or other
materials. Generally this rating is used to indicate the potential to reactive if
the material is heated, jarred, or shocked.. A low rating of 1 indicates
a material that is normally stable but may be reactive if heated.
The more hazardous ratings of 2, 3, and 4 indicate a material is
capable of violent reaction, shock/rapid heating and detonation respectively (NFPA
Other Hazard Information -
An open space at the bottom of the NFPA diagram can be used to indicate additional
information about the chemical or material. This information may include the
chemical or material's radioactivity, proper fire extinguishing agent, skin hazard, its
use in pressurized containers, protective equipment required, or unusual reactivity with
water. For example, the usual signal to indicate unusual reactivity with water is
the letter "W" with a long line through the center. Similarly
the words ACID, COR (corrosive), RAD (radiation), OXY
(oxidizer), Rad (radioactive), CARC (carcinogen) or other abbreviations may be used.
The following shows a summary of the NFPA
rating system used for labeling secondary containers of chemicals. (Click the image for a
screen size printable label)
ratings for common chemicals