Information not required by the CPR should not be placed within the WHMIS label border. When WHMIS was being developed, it was agreed that "to avoid confusion with other information on a container, e.g., TDG Regulations, the WHMIS label information must be clearly distinguishable from, and not in conflict with, other printed information on the container. More specifically: The WHMIS label information would be within a distinctive border"; (ref.: Report of the [WHMIS] Steering Committee, p.16).

WHMIS labels should be durable and clearly display the required information for the life of the product. No recommendation is made for a specific test to determine whether the labelling information will be sufficiently durable to remain legible under normal conditions of transportation, storage, sale and use. However, hazard warnings must remain legible throughout the lifetime of the product, and not fade, run, rub off or peel off under normal use. Print that can be dissolved by the contents, or paper and plastic label sleeves that are easily removable, are not acceptable.