3.0 Chemical Labeling

Revised February, 2021

3.1 Labeling of Incoming (Shipped) Chemicals

Chemical manufacturers, importers, and distributors are required by regulation to label every hazardous chemical container as described in section 3.2. As long as the original label is affixed and readable, individuals receiving or using the chemical do not have to take any action. If a label is missing or not readable, the responsible user must affix a replacement label that contains the information described in section 3.2.

3.2 Label Information for Incoming (Shipped) Chemicals

Incoming chemicals are those that are obtained from a chemical manufacturer, importer, or distributor. All labels on incoming chemicals must include the product identifier, supplier identification, precautionary statements, hazard pictograms, a signal word, hazard statements, and supplemental information.

  • The PRODUCT IDENTIFIER contains the name of the item as well as the product number or other distinguishing information used by the manufacturer, importer, or distributor. An identical identifier must appear both on the product label and on the corresponding safety data sheet.
  • PICTOGRAMS indicate the hazard categories that are applicable to the chemical.
  • The SUPPLIER IDENTIFICATION section contains the name of the manufacturer, importer, or other responsible party along with the address and contact information.
  • A SIGNAL WORD indicating the level of hazard. Only two signal words may be used; “DANGER” for the more severe hazard level and “WARNING” for lesser hazards.
  • Standardized HAZARD STATEMENTS describe the nature of the hazards, and where appropriate, the degree of the hazards. HAZARD STATEMENTS are specific to hazard classification categories and as such should appear identically on all chemicals possessing the same hazard, regardless of the manufacturer.
  • PRECAUTIONARY STATEMENTS describe measures that the chemical user should take in order to minimize the likelihood of adverse effects; however, the appropriate measures must be determined by an evaluation of the specific use of the chemical.
  • SUPPLEMENTARY INFORMATION includes any additional instruction or information that the label producer deems helpful.

3.3 Hazard Classification and Ratings

Chemical manufacturers and importers are responsible for evaluating chemicals and assigning applicable health and physical hazards. Specific criteria has been established for the classification of chemical health and physical hazards, with many hazard classes sub-divided into hazard categories based on the severity of the hazard. Numerical, alphanumeric, or alphabetic ratings indicate the severity of the hazard. Under the OSHA Hazard Communication Standard (HCS) criteria, the highest hazards are rated as “1” and lower hazards are rated as successively higher numerical ratings (lower the number, higher the hazard). Analogously, the lower the alphanumeric or alphabetic character, the higher the hazard. The following two tables provide a summary of the hazard classes and associated hazard category ratings.

The hazard rating scheme required by the HCS is in contrast to the commonly used National Fire Protection Association (NFPA) 704 System (represented by the “fire diamond”) and the Hazardous Materials Identification System (HMIS). Both of these systems use a numerical hazard rating scheme where “1” indicates the lowest hazard and “4” indicates the highest hazard. Tables 1 and 2 summarize the health and physical hazards that manufacturers and importer must consider when classifying a chemical under the OSHA HCS.

Table 1. Chemical Health Hazard Classifications
Hazard Class Hazard Categories
Acute Toxicity: oral, dermal, inhalation 1, 2, 3, 4
Skin Corrosion/Irritation 1A, 1B, 1C, 2 (irrit)
Serious Eye Damage/Irritation 1, 2A (irrit), 2B (irrit)
Respiratory/Skin Sensitization 1A, 1B
Germ Cell Mutagenicity 1A, 1B, 2
Carcinogenicity 1A, 1B, 2
Reproductive Toxicity 1A, 1B, 2, lactation
Specific Organ Toxicity – single exposure 1, 2, 3
Specific Organ Toxicity – repeated exposure 1, 2
Aspiration Hazard 1
Simple Asphyxiants Single Category
Explosives Unstable Explosives, Div. 1.1, Div. 1.2, Div. 1.3, Div 1.4, Div 1.5, Div 1.6
Flammable Gases 1, 2
Flammable Aerosols 1, 2
Oxidizing Gases 1
Gases Under Pressure N/A
Compressed Gases Single category
Liquefied Gases Single category
Refrigerated Liquefied Gases Single Category
Dissolved Gases Single Category
Flammable Liquids 1, 2, 3, 4
Flammable Solids 1, 2
Self-Reactive Substances Type A, Type B, Type C, Type D, Type E, Type F, Type G
Pyrophoric Liquids 1
Pyrophoric Solids 1
Self-Heating Substances 1, 2
Chemicals which, in contact with water, emit flammable gases 1, 2, 3
Oxidizing Liquids 1, 2, 3
Oxidizing Solids 1, 2, 3
Organic Peroxides Type A, Type B, Type C, Type D, Type E, Type F, Type G
Corrosive to Metals 1

3.4 Hazard Category Pictograms

The HCS requires pictograms on chemical labels to alert users of the chemical hazards to which they may be exposed. Each pictogram consists of a symbol on a white background framed within a red border and represents a distinct hazard category. The pictograms included on a specific chemical label are determined by the chemical hazard classification. The pictograms that may be used are shown below, with each chemical label including all pictograms that are applicable.

Health Hazard

  • Carcinogen
  • Mutagenicy
  • Reproductive Toxicity
  • Respiratory Sensitizer
  • Target Organ Toxicity
  • Aspiration Toxicity

An icon depticting a human silhouette behind a six-pointed stellar shape.


  • Flammables
  • Pyrophorics
  • Emits Flammable Gas
  • Self-Reactivates
  • Organic Peroxides

An icon depicting a flame.

Exclamation Mark

  • Irritant (skin and eye)
  • Skin Sensitizer
  • Acute Toxicity (harmful)
  • Narcotic Effects
  • Respiratory Tract Irritant
  • Hazardous to Ozone Layer(non mandatory)

An icon depicting an exclamation mark.

Gas Cylinder

  • Gases Under Pressure

An icon depicting a cylinder or bottle.


  • Skin Corrosion/burns
  • Eye Damage
  • Corrosive to Metals

An icon depicting a corroding material.

Exploding Bomb

  • Explosive
  • Self-Reactives
  • Organic Peroxides

An icon depicting an exploding object.

Flame over Circle

  • Oxidizers

An icon depicting a circle in front of a flame.

Environment *(Non Mandatory)

  • Aquatic Toxicity

An icon depicting a tree and a stream.

Skull and Crossbones

  • Acute Toxicity (fatal or toxic)

An icon depicting a skull and crossbones.

3.5 Replacement Labels

Each hazardous chemical container in the workplace must be labeled as described in section 3.2, or alternatively, labeling must include the product identifier and at least general information regarding the hazards using words, symbols, etc. If, for any reason, this information is not legible on the container a proper label must be promptly attached to the container. Chemical users can generate labels themselves or labels can be obtained from vendors. Contact EH&S if guidance is needed on generating or obtaining labels.

3.6 Secondary Containers

When transferring material to a secondary container (e.g. bucket, spray bottle, can, or jar), the person accomplishing the transfer must ensure that the secondary container is compatible with the material, and that the container is labeled as described in section 3.5.

NOTE: If the secondary container remains in the direct control of the person using it at all times and is emptied by the end of the work shift, a label is not required, but is highly suggested.

4.0 Chemical Inventory