What is a hazardous chemical?

Oregon OSHA’s hazard communication rule for general industry, Hazard Communication, 1910.1200, defines a hazardous chemical as any chemical that is classified as a physical hazard, a health hazard, a simple asphyxiate, combustible dust, pyrophoric gas, or a “hazard not otherwise classified.”

Chemicals that are physical hazards

Chemicals that are physical hazards are:

• Corrosive to metals
• Explosive
• Flammable (includes aerosols, gases, liquids, and solids)
• Pressurized gases
• Organic peroxides
• Oxidizers (includes gases, liquids, and solids)
• Pyrophoric (includes liquids and solids)
• Self-heating substances
• Self-reactive substances
• Substances that emit flammable gases in contact with water

Chemicals that are health hazards

Chemicals that are health hazards are classified by how they affect tissue, vital organs, or internal systems. These health effects include:

• Acute toxicity
• Aspiration toxicity
• Carcinogenicity
• Germ cell mutagenicity
• Reproductive toxicology
• Respiratory or skin sensitization
• Serious eye damage or eye irritation
• Skin corrosion and irritation
• Target organ systemic toxicity (repeated exposure)
• Target organ systemic toxicity (single exposure)

Health effects also range from short-duration symptoms that often appear immediately (acute effects) to persistent symptoms that usually appear after longer exposures (chronic effects).

Simple asphyxiates

A simple asphyxiate is a substance or mixture that displaces oxygen in the ambient atmosphere and can cause oxygen deprivation in those who are exposed.

Combustible dust

Combustible dust is a particulate solid that becomes a fire hazard or deflagration hazard when suspended in air or other oxidizing medium over a range of concentrations.

Pyrophoric gas

A pyrophoric gas is a chemical in a gaseous state that will ignite spontaneously in air at a temperature of 130 degrees F or below.

Hazards not otherwise classified

These are chemicals that may have adverse physical or health effects (based on scientific evidence), but do not currently meet federal OSHA’s criteria for a physical or health hazard.

These hazards do not have to be disclosed on a label but must be disclosed in section two of a Safety Data Sheet. Chemical manufacturers and importers are expected to assess these hazards when they are evaluating their products’ physical and health hazards.

How to determine if a chemical is hazardous

A chemical is hazardous if it is listed in one of the following documents:

• Oregon OSHA’s Division 2, Subdivision Z safety and health rules, Toxic and Hazardous Substances; Division 3, Subdivision Z, Toxic and Hazardous Substances (Construction); Division 4, Subdivision Z, Chemical/Toxins (Agriculture)
• Threshold Limit Values for Chemical Substances and Physical Agents in the Work Environment (latest edition). Published by the American Conference of Industrial Hygienists (ACGIH)
• The Registry of Toxic Effects of Chemical Substances, published by the National Institute for Occupational Safety and Health (NIOSH)