Hazardous material must be easily identifiable to workers on the job. This is the purpose of the WHMIS label, which is the first hazard warning workers are likely to see.

In most cases, this label will be a supplier label - the label placed on the container of hazardous material by the supplier before shipping. Or, the supplier label may be included in the shipment and placed on the container by the receiver when the shipment arrives at the workplace where hazardous material will be used. In other cases, the label may be a workplace label.

Workplace labels are also used on hazardous material, which has been transferred from its original container after arrival in the workplace. Both supplier labels and workplace labels are required to have certain kinds of information for the benefit of workers who use the materials or come into contact with them on the job.

There are some specific components that MUST be on the Supplier label.