Canada Occupational Health and Safety Regulations

7.2 (1) For the purposes of this Part, the exposure of an employee to sound shall be measured using an instrument that

• (a) is recommended for that measurement in clause 4.3 of CSA Standard CAN/CSA-Z107.56-13, Measurement of Noise Exposure; and

• (b) meets the requirements for such an instrument set out in clause 4 of the Standard referred to in paragraph (a).

(2) The exposure of an employee to sound shall be measured in accordance with clauses 5, 6.4.1, 6.4.4, 6.5.2, 6.5.4, 6.6.2 and 6.6.4 of the Standard referred to in paragraph (1)(a).

(3) For the purposes of this Part, the measurement and calculation of the noise exposure level (L_{ex, 8}) to which an employee is exposed shall take into account the exposure of the employee to A-weighted sound pressure levels of 74 dBA and greater.

(4) The measurement and calculation of the noise exposure level (L_{ex, 8}) referred to in subsection (3) may also take into account the exposure of the employee to A-weighted sound pressure levels that are less than 74 dBA.