Labeling and Marking Systems

Always read the labels
on the products you use!!!

These will provide you with a wealth of information you need to know in order to use the product safely.

In addition to the manufacturers' labels which are provided on most chemical products, OSU uses three labeling and marking systems:

  • Hazardous Materials Information System (HMIS) labels
  • National Fire Protection Association (NFPA) diamonds
  • Uniform Laboratory Hazard Signage (ULHS) system

The first two of these systems rely on color coding and a numerical rating system to identify the hazard and its severity. The ULHS system identifies the areas where hazardous substances are used or stored through pictograph symbols.

NFPA Diamonds

OSU buildings will have NFPA diamonds located inside the main entrance (usually near the fire alarm panel) or on the outside of the main entrance door. Each diamond represents a different hazard.

Blue = Health Hazard
Red = Flammability
Yellow = Reactivity
White = Special Hazard Information

A numerical rating will also be provided in the blue, red, and yellow diamonds. This number indicates the severity of the hazard, with a 0 indicating no hazard and 4 indicating the most severe hazard.

These placards represent the "worst" of what is in the building, but they will not provide specific chemical names, quantities, or locations. They are designed to give emergency personnel a general idea of the worst hazards present in a building or area.

Key to the NFPA Diamond

HMIS Labels

The HMIS labeling system operates on the same principle as the NFPA diamond. Blue indicates health hazard, red indicates flammability, yellow indicates reactivity, and special information (such as what personal protective equipment to wear) will be provided in the white section. It also uses a numerical system from 0-4 to indicate the severity of the hazard.

These labels should be used on individual containers of hazardous materials (ie. barrels, bottles, cans, buckets, tubs, etc) so that there are never any unlabeled containers in the work area. It is recommended that they be used on all containers, even if the manufacturer's label is still in place; however, this is just a recommendation.

Always regard unlabeled containers as dangerous!

If a product or chemical is removed from its original container into another container which doesn't have a manufacturer's label, the second container must be labeled with an HMIS label with the appropriate information filled out.

HMIS labels are available in a variety of sizes from the EHS department.

HMIS Label

Key To HMIS Label Numerical Ratings


Deadly: even the slightest exposure to this substance would be life threatening. Only specialized protective clothing, for these materials, should be worn.
Extreme Danger: serious injury would result from exposure to this substance. Do not expose any body surface to these materials. Full protective measures should be taken.
Dangerous: exposure to this substance would be hazardous to health. Protective measures are indicated.
Slight Hazard: irritation or minor injury would result from exposure to this substance. Protective measures are indicated.
No Hazard: exposure to this substance offers no significant risk to health.


Flash Point Below 73F and Boiling Point Below 100F: this substance is very flammable, volatile or explosive depending on its state. Extreme caution should be used in handling or storing of these materials.
Flash Point Below 100F: flammable, volatile or explosive under almost all normal temperature conditions. Exercise great caution in storage or handling of these materials.
Flash Point Below 200F: moderately heated conditions may ignite this substance. Caution procedures should be employed in handling.
Flash Point Above 200F: this substance must be preheated to ignite. Most combustible solids would be in this category.
Will Not Burn: substances that will not burn.


May Detonate: substances that are readily capable of detonation or explosion at normal temperatures and pressures. Evacuate area if exposed to heat or fire.
Explosive: substances that are readily capable of detonation or explosion by a strong initiating source, such as heat, shock or water. Monitor from behind explosion-resistant barriers.
Unstable: violent chemical changes are possible at normal or elevated temperatures and pressures. Potentially violent or explosive reaction may occur when mixed with water. Monitor from a safe distance.
Normally stable: substances that may become unstable at elevated temperatures and pressures or when mixed with water. Approach with caution.
Stable: substances which will remain stable when exposed to heat, pressure or water.

Uniform Laboratory Hazard Signage

Laboratories should be marked with the appropriate pictographic symbols to warn employees, visitors, and emergency responders what precautions should be observed when entering the laboratory, as well as what hazards to expect inside.

EHS can provide pictographs for a variety of hazards such as these:


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