Hazardous chemical labels in the United States must include six elements: a product identifier, signal word, hazard statement(s), precautionary statement(s), pictogram(s), and the name, address, and phone number of the chemical manufacturer, importer, or distributor. These requirements come from OSHA’s Hazard Communication Standard, which aligns with the Globally Harmonized System (GHS) used internationally.
Product Identifier
The product identifier is the name or code that links the chemical on the label to its Safety Data Sheet (SDS). This can be a chemical name, a trade name, or a code number, but it must be consistent between the label and the SDS so workers can quickly look up detailed safety information. Every hazardous chemical label starts here.
Signal Word
Only two signal words exist: “Danger” and “Warning.” “Danger” is reserved for more severe hazards, while “Warning” indicates a less severe one. A label will never display both. If a chemical poses multiple hazards and one qualifies for “Danger” while another qualifies for “Warning,” only “Danger” appears. This keeps the label simple and ensures the most serious risk level is immediately visible.
Pictograms
Pictograms are the red-bordered diamond symbols that communicate hazard types at a glance. OSHA recognizes eight mandatory pictograms, plus one non-mandatory environmental symbol:
- Flame: Flammable liquids, gases, and solids, as well as chemicals that self-heat or emit flammable gas.
- Flame over circle: Oxidizers, which can intensify a fire by supplying oxygen.
- Exploding bomb: Explosives, self-reactive chemicals, and organic peroxides.
- Skull and crossbones: Chemicals that are acutely toxic, meaning they can be fatal or toxic through a single or short exposure.
- Corrosion: Chemicals that cause skin burns, serious eye damage, or corrode metals.
- Gas cylinder: Gases stored under pressure that may explode if heated.
- Health hazard (silhouette with starburst on chest): Long-term health effects like cancer, reproductive harm, organ damage, or respiratory sensitization.
- Exclamation mark: Less severe acute hazards including skin and eye irritation, allergic skin reactions, and narcotic effects.
- Environment (non-mandatory): Toxicity to aquatic life.
A single chemical can carry multiple pictograms. A corrosive solvent that is also flammable, for example, would display both the corrosion and flame symbols.
Hazard Statements
Hazard statements are standardized phrases that describe the nature and severity of each hazard. They are not written by the manufacturer. Instead, each hazard class and category has a pre-assigned statement. Physical hazards use codes in the H200 range, health hazards in the H300 range, and environmental hazards in the H400 range.
Some examples give a sense of how specific these statements get. “Extremely flammable liquid and vapor” is assigned to the most dangerous category of flammable liquids. “Fatal if swallowed” applies to the highest categories of oral acute toxicity. “May cause cancer” is the statement for known or presumed carcinogens. “Very toxic to aquatic life with long lasting effects” covers chronic aquatic toxicity. A label lists every hazard statement that applies to the chemical, so a product with both flammability and skin corrosion risks would carry statements for each.
Precautionary Statements
Precautionary statements tell you what to actually do about the hazards. They fall into four categories:
- Prevention: Steps to avoid exposure or an incident, such as wearing protective gloves or keeping away from heat sources.
- Response: First aid or emergency actions if exposure occurs, like rinsing skin with water or calling a poison center.
- Storage: How to store the chemical safely, including temperature requirements or incompatible materials to separate it from.
- Disposal: Instructions for getting rid of the chemical and its container in compliance with regulations.
Like hazard statements, precautionary statements are standardized. The manufacturer selects from a set list based on the chemical’s classification rather than writing their own language.
Supplier Identification
The label must include the name, address, and telephone number of the chemical manufacturer, importer, or distributor. This gives you a direct point of contact for emergencies or additional safety information beyond what the label and SDS provide.
Workplace and Secondary Container Labels
When you transfer a chemical from its original container into a secondary one, like a spray bottle or smaller jug, different rules apply. OSHA requires that secondary containers carry the product identifier plus words, pictures, or symbols that communicate the general hazards. You do not need to replicate the full manufacturer label with precautionary statements, hazard statements, or the supplier’s address.
The catch is that employees must still have access to the complete hazard information. Employers typically meet this requirement by keeping Safety Data Sheets immediately available in the work area during every shift. If an employer uses a simplified labeling system on secondary containers, they carry the burden of proving that workers are just as informed as they would be with full labels. Locking SDS binders in an office that workers cannot freely access does not meet the standard.
Rules for Small Containers
Labeling a tiny vial with all six elements is not always physically possible. OSHA’s updated Hazard Communication Standard addresses this with tiered requirements based on container size.
Containers holding 100 milliliters or less can use an abbreviated label if the manufacturer can show that pull-out labels, fold-back labels, or tags are not feasible. The abbreviated label must still include the product identifier, pictograms, signal word, the manufacturer’s name and phone number, and a note directing the reader to the outer packaging for full details. For very small containers of 3 milliliters or less, only the product identifier is required on the container itself, provided a full label appears on the immediate outer packaging. The outer package must also include a statement that the small containers inside should be stored in that labeled packaging when not in use.
How Aerosol Labels Are Changing
Recent updates to the Hazard Communication Standard expanded the aerosol hazard class. Previously, only flammable aerosols had their own classification. Now, non-flammable aerosols fall under a new Category 3, covering aerosol products that contain 1% or less flammable components by mass and have low heat of combustion. These non-flammable aerosols do not require a pictogram, but their labels must include the hazard statement “pressurized container, may burst if heated.” Flammable aerosols in Categories 1 and 2 must display the flame pictogram and, if no higher-severity signal word is already required, the signal word “Warning.”