Appendix B: Assignment of HMIS Ratings

Chemical Classification | Health Hazard | Fire Hazard | Reactivity Hazard


The Biology Safety Committee assigns HMIS ratings:

Chemical classification:

Each chemical is classified. If a chemical can be described by more than one classification, its primary classification will consider the most hazardous aspect of the material. If applicable, secondary and tertiary classifications will also be included on the HMIS. The classes of chemicals that the biology department uses are:

Poison: The chemical has the potential to be a severe health risk. Abbreviation = PO.
Flammable: The chemical is extremely flammable or combustible. The chemical must be stored in a vented flammable cabinet or a flammable storage area. Abbreviation = FL.
Corrosive: The chemical can cause irreversible damage to tissue. Acids and bases must not be stored together. Abbreviation = CO.
Oxidizer: The chemical has the ability to cause or drive a fire or explosion. Do not store this chemical near flammable or combustible chemicals. Abbreviation = OX.
Irritant: The chemical has the potential to cause reversible inflammation of living tissue. All hazard ratings are two or less. Abbreviation = IR.
Low hazard: The chemical poses minimal risk. All hazard ratings are one or less. Abbreviation = LH.
Special: The chemical possesses a special hazard. This might mean that it is incompatible with other members of its storage class. In this case, a special storage area will be selected.

Assignation of the health hazard rating (blue zone on HMIS label)

Rankings from zero to four are made, indicating the danger presented by a chemical either acute or chronic, to living tissue if inhaled, ingested or absorbed. Toxic effects are evaluated by considering the oral rat LD50 data, or the evidence of acute or chronic toxicity, carcinogenicity or teratogenicity revealed by the MSDS. Health hazard rankings are listed below:

Acute hazards
4 = Extreme hazard, LD50 is less than 5 mg/kg.
3 = Serious hazard, LD50 is between 5 and 50 mg/kg.
2 = Moderate hazard, LD50 is between 50 and 500 mg/kg.
1 = Slight Risk, LD50 is between 500mg/kg and 5 g/kg.
0= Practically Non-toxic, LD50 is greater than 5 g/kg.

Carcinogens
4= Extreme hazard, the chemical is a known or suspected human carcinogen. IARC classification 1 or 2A

3 = Serious hazard, the chemical is a known or suspected animal carcinogen. IARC classification 2B.

Corrosives
4 = 1 < pH >13

3 = pH = 1-2 or pH = 12-13

2 = pH = 2-4 or pH = 10-12

Assignation of the fire hazard rating (red zone on HMIS label):

The fire hazard is ranked from zero to four are made indicating the fire danger presented by a chemical. Use the NFPA flammability rating if available. If the NFPA flammability rating is not available, assign a ranking using the guidelines below:

4 = Extreme hazard, the flashpoint is less than 73 °F or 23 °C.
3 = Serious hazard, the flashpoint is between 73-100 °F or 23-38 °C.
2 = Moderate hazard, the flashpoint is between 100-200 °F or 38-93 °C.
1 = Slight Risk, the flashpoint is greater than 200 °F or 93 °C.
0 = Will not burn.

Assignation of the reactivity hazard rating (yellow zone on HMIS label):

The reactivity is ranked from zero to four indicating the explosion hazard presented by a chemical.

4 = Extreme hazard, the chemical might explode or ignite spontaneously (under room temperature or normal atmospheric pressure) or is water reactive.
3 = Serious hazard, shock or heat might cause an explosion.
2 = Moderate hazard, the chemical might or will undergo a violent chemical change.
1 = Slight risk, the chemical is unstable if heated.
0 = Stable.