Understanding the Hazardous Materials Identification System (HMIS)
The Hazardous Materials Identification System (HMIS) is a hazard rating system developed by the American Coatings Association (ACA). It was developed to help employers comply with the US Occupational Safety and Health Administration's (OSHA) workplace labeling requirements.
HMIS is represented by a color-coded, diamond icon. The colors of the HMIS diamond are Blue, Red, Yellow, and White. They are color-coded to make reading this warning symbol quick and easy.
Within each color category, there are number ratings from 0-4.
4 - Extreme
3 - High
2 - Moderate
1 - Light
0 - Insignificant
Each rating is spelled out below with specifics to each category.
HMIS is important information to understand when using any kind of chemical. The HMIS should be printed on all chemical bottle labels. All chemical users should know how to interpret this symbol.
BLUE - Health
The Health section rates the health hazards of the material.
4 Life-threatening, major or permanent damage may result from single or repeated overexposures, for instance, hydrogen
3 Major injury is likely unless prompt action is taken and medical treatment is given.
2 A temporary or minor injury may occur, for instance, diethyl ether.
1 Irritation or minor reversible injury possible.
0 No significant risk to health.
RED - Flammability
The Flammability section rates the fire and flammability hazards of the material.
4 Flammable gases, or very volatile flammable liquids with flash points below 73 °F / 23 °C. Boiling points below
100 °F / 38 °C. Materials may ignite spontaneously with air, for instance, propane.
3 Materials capable of igniting under almost all normal temperature conditions. Includes flammable liquids with flashpoints
below 73 °F / 23 °C. Boiling points above 100 °F / 38 °C. Includes liquids with flashpoints between 73 °F and 100 °F.
2 Materials that must be moderately heated or exposed to high ambient temperatures before ignition will occur. Includes
liquids having a flashpoint at or above 100 °F / 38 °C but below 200 °F / 93 °C, for instance, diesel fuel.
1 Materials that must be preheated before ignition will occur. Includes liquids, solids, and semi-solids having a flashpoint
above 200 °F / 93 °C for instance, canola oil.
0 Materials that will not burn, for instance, water.
YELLOW-ORANGE- Reactivity/Physical Hazard
The Reactivity section rates hazards related to reactivity and physical hazard. There are seven recognized hazard classes: Water Reactives, Organic Peroxides, Explosives, Compressed gases, Pyrophoric materials, Oxidizers, and Unstable Reactives.
4 Materials, at normal temperature and pressure, that are capable of: explosive water reaction, detonation or explosive
decomposition, polymerization, or self-reaction, for instance, chlorine dioxide, nitroglycerin.
3 Materials that may form explosive mixtures with water and are capable of detonation or explosive reaction in the presence
of a strong initiating source. Materials may polymerize, decompose, self-react, or undergo other chemical change at normal
temperature and pressure with moderate risk of explosion, for instance, ammonium nitrate.
2 Materials that are unstable and may undergo violent chemical changes at normal temperature and pressure with low risk for
explosion. Materials may react violently with water or form peroxides upon exposure to air, for instance, potassium, sodium.
1 Materials that are normally stable but can become unstable or self-react at high temperatures and pressures. Materials may
react non-violently with water or undergo hazardous polymerization in the absence of inhibitors, for instance, propene.
0 Materials that are normally stable, even under fire conditions, and will not react with water, polymerize, decompose,
condense, or self-react. Non-explosives, for instance, helium.
White - Personal Protection Equipment
The Personal Protection Equipment (PPE) section addresses which PPE should be worn when working with the material.
This chart shows clearly what PPE is required.