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Warning Labels

Labels provide an immediate warning of the hazards you may be exposed to. Generally, warning labels are required on all containers to alert the user of the contained chemical, its hazardous properties, and handling precautions. OSHA requires chemical manufacturers to make sure each hazardous chemical container is labeled before leaving the manufacturing facility.

If a warning label is missing or has become illegible, contact your supervisor.

The Hazard Communication Standard

As of June 1, 2015, the Hazard Communication Standard (HCS) will require pictograms on 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 or hazards. The pictogram on the label is determined by the chemical hazard classification:

• the sign depicting damage to the human body signifies health hazards such as carcinogens, mutagenicity, reproductive toxicity, respiratory sensitizers, targeted organ toxicity, and aspiration toxicity
• the flame pictogram signifies flammables, pyrophorics, self-heating substances, substances that emit flammable gas, self-reactives, and organic peroxides
• the sign with an exclamation mark signifies contents such as irritants to skin and eyes, skin sensitizers, acute toxicity, narcotic effects, respiratory tract irritants, and hazards to the ozone layer
• the sign with a gas cylinder on it signifies gases under pressure
• the corrosion symbol that shows acid damaging material and a hand indicates hazards that can cause skin corrosion and burns, eye damage, and corrosion to metals
• the sign with an exploding bomb on it signifies contents that include explosives, self-reactives, and organic peroxides
• the sign with a flame over circle indicates the presence of oxidizers
• the environment sign shows damage to a river system, and represents aquatic toxicity (this sign is non-mandatory), and
• the skull and crossbones sign indicates acute, potentially fatal, toxicity

Secondary container

Pipes or piping systems don't have to be labeled under this standard. A secondary container or transfer container doesn't have to be labeled if only one person has custody of the container, and the material in the container is used immediately and completely in one shift.

If you do not immediately use all of the material or maintain sole custody of it, then the container must be labeled with information identifying the contents and their hazards.

Bulk containers

Before shipment, the manufacturer must label products that contain hazardous materials. Some products are received in bulk containers and must be transferred to smaller containers for transportation and use. Products that are transferred to other containers must be labeled in compliance with OSHA regulations. A label may not be shipped separately. To do so would defeat the purpose of providing an immediate hazard warning.

Labeling systems

Several labeling systems are used to alert the user of the contained chemical and its hazards. Four of the most common are as follows:

The Department of Transportation Labeling System (DOT)

DOT labels and placards are normally found on incoming shipments of larger quantities of potentially harmful chemicals. The DOT requires specific labeling and identification of hazardous substances shipped by public highways, water, rail, or airfreight.

The Hazardous Material Identification System (HMIS®) and the GHS System

• symbols, or hazard pictograms, are used to convey health, physical and environmental hazard information, assigned to a GHS hazard class and category
• signal words, such as "Danger" or "Warning", are used to emphasize hazards and indicate the relative level of severity of the hazard, assigned to a GHS hazard class and category
• hazard statements are standard phrases assigned to a hazard class and category that describe the nature of the hazard
• precautionary statements and pictograms are measures to minimize or prevent adverse effects
• product identifiers, or ingredient disclosure, are the name or number used for a hazardous product on a label or in the Safety Data Sheet
• supplier identification, such as the name, address and telephone number, should be provided on the label, and
• supplemental information which refers to non-harmonized information

HMIS® uses colored bars. The HMIS® was developed by the National Paint and Coatings Association, or NPCA. It communicates the chronic and acute health hazards, flammability, and physical hazards, as well as PPE requirements. The HMIS® system isn't intended for emergency circumstances.

HMIS® uses a numbering system of 0-4, where 4 is a severe hazard and 0 is a minimal hazard.

The HMIS® system uses an asterisk (*) to designate material as a carcinogen or as one that has adverse effects due to chronic exposure. The asterisk will be found in the space next to the numerical ranking in the blue bar. The orange section of the label refers to any physical hazard the material may pose. In the white section of an HMIS® label, letters or symbols refer to different levels of personal protective equipment, or PPE, requirements.

The National Fire Protection Association (NFPA)

The NFPA label is a diamond-shaped warning label that's commonly used in the workplace, but is meant primarily for firefighters and emergency responders. This warning label must include the name of the material and any special health and physical warnings. The chemical formula of the material is optional. The material's name, located at the top of the label, is listed as it appears on the original container. Special warnings may be listed in the section below the diamond.

The NFPA system uses a numeric code (0-4) in each color-coded hazard diamond. Each color represents a type of hazard as follows:

• red represents a flammability hazard
• blue represents a health hazard
• yellow represents an instability hazard, and
• white represents a special hazard

The number in each color-coded section represents the severity of the hazard. For example, the number 0 represents no hazard and the number 4 represents a potentially fatal hazard. This same numbering system is used with the HMIS® labeling system.

Remember the following points regarding chemical warning labels:

• never remove or deface labels on containers holding hazardous chemicals, and
• ensure labels are legible and clearly displayed – employers may add information in another language, but it must always be provided in English as well

When handling chemicals, follow these guidelines:

• once the container is empty, the label must be removed, defaced, or relabeled as empty
• manufacturers or employers must revise labels within three months after any significant information changes, and
• report missing or illegible warning labels