NFPA Hazard Identification System

Special Precautions
Protective Gear Required

(White)

Special Precautions
The fourth, white, field of the hazard signal can have variable content, depending on who prepared the signal. The 1990 edition of the National Fire Codes (section 704, chapter 5) specifies only two symbols. Additional symbols are commonly included. The field may also be left blank if no special hazards are present.

Protective Gear Required
An alternative set of symbols from the Lab Safety Supply Inc. HMIG labeling system is used in the introductory chemistry laboratory at the University of Oregon. These symbols indicate the type(s) of protective equipment that must be used whenever the material in question is handled. The symbols are the letters A - K and X, with 'A' indicating that goggles must be worn, and successive letters indicating progressively greater amounts of protective gear. A full description of the symbols used is found on posters placed at various points around the lab.

Symbols specified in National Fire Codes, section 704
	Material shows unusual reactivity with water (i.e. don't put water on it).	Example: magnesium metal
OX	Material possesses oxidizing properties.	Example: ammonium nitrate (fertilizer used in Oklahoma City bomb)
Other symbols commonly used
ACID	Material is an acid.
ALK	Material is a base (alkaline).
COR	Material is corrosive.
	Material is radioactive.