Canada–Nova Scotia Offshore Area Occupational Health and Safety Regulations — 156
Investigation and assessment 156 (1) The employer must, for the purpose of investigating and assessing potential exposure to hazardous substances under paragraph 210.022(f) of the Act, before the work that gives rise to the potential exposure begins, (a) obtain from a competent person designated by it, in consultation with the workplace committee or coordinator, as the case may be, a signed written report that (i) addresses the following factors in respect of each hazardous substance to which employees may be exposed: (A) the substance’s chemical, biological and physical properties, (B) the routes of exposure to the substance, (C) the acute and chronic effects on health of exposure to the substance, (D) the manner in which the substance is produced, stored, used, handled and disposed of at the workplace, (E) the control methods used to eliminate or reduce the employees’ exposure to the substance, and (F) the quantity, concentration or level of substance to which the employees may be exposed, including, in the case of an airborne chemical agent, whether that concentration is likely to exceed 50% of the threshold limit value for that agent referred to in paragraph 157 (1)(a), and (ii) sets out the competent person’s recommendations regarding compliance with the provisions of the Act and these Regulations respecting hazardous substances, including recommendations in respect of sampling, testing and medical examinations of employees; (b) if the report referred to in paragraph (a) recommends the medical examination of employees, (i) obtain from a physician with specialized knowledge of the hazardous substance to which the employees may be exposed a written opinion, to be retained with the report, as to whether the medical examination is necessary, and (ii) if it is confirmed that the examination is necessary, obtain the results of a medical examination of each employee, carried out by a physician acceptable to that employee and at the employer’s expense, indicating whether the employee is fit to be exposed to the substance and, if so, any restrictions that ought to be imposed on their exposure; and (c) assess whether and to what extent medical monitoring of employees is necessary and, if the employer determines that it is necessary — or if requested by the Board under paragraph 210.067(1)(f) of the Act — implement a program for the medical monitoring of the employees. Combined effect (2) If two or more hazardous substances have a similar toxicological effect on the same target organ or system, their combined effect must be considered for the purpose of the investigation and assessment, using the additive mixture formula set out in the American Conference of Governmental Industrial Hygienists publication TLVs and BEIs: Based on the Documentation of the Threshold Limit Values for Chemical Substances and Physical Agents & Biological Exposure Indices . Testing methodology (3) If it is likely that the concentration of an airborne chemical agent referred to in clause (1)(a)(i)(F) exceeds the threshold limit value for that agent referred to in paragraph 157 (1)(a), the concentration must be determined using a test that conforms to the United States National Institute for Occupational Safety and Health’s NIOSH Manual of Analytical Methods , if such a test exists for that agent.