Who is exempt from the no-exposure requirement when a contaminant is present at levels above the limit?

• A. A person wearing a hard hat only.
• B. A person not wearing PPE in an emergency.
• C. A person wearing self-contained breathing apparatus in an emergency or for a mines rescue purpose.
• D. A visitor.

Answer: (C)

When a contaminant is present at levels above the limit, the usual rule is that people should not be exposed. There is a recognized exception for those who are using appropriate respiratory protection during emergencies or mine rescue operations. A person wearing a self-contained breathing apparatus (SCBA) has an independent air supply, which protects them from inhaling contaminated air while they perform urgent rescue or emergency tasks. Because the SCBA directly mitigates the inhalation risk, this person is treated as exempt from the no-exposure requirement in that emergency or rescue context.

The other scenarios do not provide this protective mechanism against breathing in the contaminant: a hard hat alone does not address inhalation risk, a person in an emergency without proper respiratory protection is still exposed, and a visitor isn’t authorized to operate in such conditions under these rules.