Safety News from UVA

News for September 27, 2007

You may have noticed new warning signs posted around the Dell buildings like the one to the right. These are Hazard Communication Signs that were put up by the UVA Fire Marshal in the Fall of 2006. The signs are National Fire Protection Association (NFPA) codes for rating health, flammability, and instability of products stored in a particular location. The signs were installed on windows and doors facing outside of painting, photography, printmaking, and the 3 sculpture studio to help emergency response personnel quickly identify what they might encounter upon entering the studios during an emergency.

What do the numbers and symbols on an NFPA fire diamond mean? The diamond is broken into four sections. Numbers in the three colored sections range from 0 (least severe hazard) to 4 (most severe hazard). The fourth (white) section is left blank and is used only to denote special fire fighting measures/hazards.

Health Hazard
4 Very short exposure could cause death or serious residual injury even though prompt medical attention was given.
3 Short exposure could cause serious temporary or residual injury even though prompt medical attention was given.
2 Intense or continued exposure could cause temporary incapacitation or possible residual injury unless prompt medical attention is given.
1 Exposure could cause irritation but only minor residual injury even if no treatment is given.
0 Exposure under fire conditions would offer no hazard beyond that of ordinary combustible materials.
Flammability
4 Will rapidly or completely vaporize at normal pressure and temperature, or is readily dispersed in air and will burn readily.
3 Liquids and solids that can be ignited under almost all ambient conditions.
2 Must be moderately heated or exposed to relatively high temperature before ignition can occur.
1 Must be preheated before ignition can occur.
0 Materials that will not burn.
Instability1
4 Readily capable of detonation or of explosive decomposition or reaction at normal temperatures and pressures.
3 Capable of detonation or explosive reaction, but requires a strong initiating source or must be heated under confinement before initiation, or reacts explosively with water.
2 Normally unstable and readily undergo violent decomposition but do not detonate. Also: may react violently with water or may form potentially explosive mixtures with water.
1 Normally stable, but can become unstable at elevated temperatures and pressures or may react with water with some release of energy, but not violently.
0 Normally stable, even under fire exposure conditions, and are not reactive with water.
1 Prior to 1996, this section was titled "Reactivity". The name was changed because many people did not understand the distinction between a "reactive hazard" and the "chemical reactivity" of the material. The numeric ratings and their meanings remain unchanged.
Special Hazards
This section is used to denote special hazards. There are only two NFPA 704 approved symbols:

OX This denotes an oxidizer, a chemical which can greatly increase the rate of combustion/fire.
W with a bar Unusual reactivity with water. This indicates a potential hazard using water to fight a fire involving this material.

Other symbols, abbreviations, and words that some organizations use in the white Special Hazards section are shown below. These uses are not compliant with NFPA 704, but we present them here in case you see them on an MSDS or container label:

ACID This indicates that the material is an acid, a corrosive material that has a pH lower than 7.0
ALK This denotes an alkaline material, also called a base. These caustic materials have a pH greater than 7.0
COR This denotes a material that is corrosive (it could be either an acid or a base).
This is a another symbol used for corrosive.
The skull and crossbones is used to denote a poison or highly toxic material. See also: CHIP Danger symbols.
The international symbol for radioactivity is used to denote radioactive hazards; radioactive materials are extremely hazardous when inhaled.
Indicates an explosive material. This symbol is somewhat redundant because explosives are easily recognized by their Instability Rating.