Final answer:
Employers must follow WHMIS 2015 requirements for any hazardous products, as WHMIS 1988 is outdated and WHMIS 2015 is the current standard incorporating GHS. Disregarding WHMIS regulations is illegal and unsafe.
Step-by-step explanation:
If an employer has products that meet both WHMIS 1988 and WHMIS 2015 in the workplace, the correct approach would be to follow WHMIS 2015 requirements. WHMIS 2015 is the updated version of the Workplace Hazardous Materials Information System, which incorporates the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) and is designed to provide more comprehensive and universally understandable information regarding hazardous products.
Employers, therefore, must comply with the newer WHMIS 2015 standards. The transition period for the implementation of WHMIS 2015 has ended, and all Canadian workplaces are expected to fully comply with WHMIS 2015. This includes having updated safety data sheets (SDS) and proper labeling in place. Disregarding WHMIS regulations is not an option as it would be both illegal and unsafe.