Assessing Designated Substances

Regulation 490/09 Designated Substances under the Occupational Health and Safety Act outlines a set of required steps to control exposure of workers by conducting an assessment to determine whether the health of a worker may be affected.  If the assessment shows that a worker is likely exposed to the substance, you must establish a control program.

LAW Environmental Consultants will recommend appropriate controls upon completion of the assessment. At the present time, the following substances have been designated:

  • acrylonitrile
  • arsenic
  • asbestos
  • benzene
  • coke oven emissions
  • ethylene oxide
  • isocyanides
  • lead
  • mercury
  • silica
  • vinyl chloride

Basically the regulation will apply if the following conditions are met:

  • the above substance is present;
  • exposure is likely if the worker can come in contact with the substance in any form (i.e. solid, liquid, dust, gas, vapour, fume or mist);
  • none of the exemptions listed in the Designated Substances Regulation apply.

For more information, please visit the Ontario Ministry of Labour website at:

Please give us a call for more information on designated substances survey or any issues affecting your facility under the Occupational Health & Safety Act.