342.51(1)An employer shall ensure that the face velocities across the operational face opening of a laboratory fume hood are quantitatively measured and the results of the measurement are documented.

342.51(2)An employer shall ensure that the capability of a laboratory fume hood to contain air contaminants and maintain an inward flow of air across its operational face opening is assessed using a smoke tube or any other appropriate qualitative method of assessment and that the method used and the results of the assessment are documented. 

342.51(3)An employer shall ensure that the measurements and assessments referred to in subsections (1) and (2) are performed

342.51(4)An employer shall ensure that airflow in a laboratory fume hood is monitored continuously if loss of airflow will result in risk to the health or safety of an employee.

342.51(5)An employer shall ensure that a laboratory fume hood is equipped with an alarm capable of indicating when the average face velocity falls below the minimum average face velocity required in paragraph 342.2(b) when the laboratory fume hood is in use.