The Hazard Communication Standard (HCS) requires 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(s). The pictogram on the label is determined by the chemical hazard classification.

Hazard pictograms are one of the key elements for the labelling of containers under the GHS, along with: an identification of the product; a signal word – either Danger or Warning – where necessary hazard statements, indicating the nature and degree of the risks posed by the product