Government amends occupational exposure limits

On February 3, 2005 the Ministry of Labour filed a set of amendments to O.Reg 833 which contains the occupational exposure limits (OEL’s) for Ontario workplaces (Amendments to the table of regulations). This amending regulation (O.Reg. 15/05) is scheduled to come into effect beginning March 1, 2005. The Ministry had requested interested parties to submit comments  last year. OHCOW submitted a brief covering 10 of the proposed changes and suggested 3 additional hazards which should be changed (wood dust, metalworking fluids and noise). 

This submission can be downloaded. click here

The amendments filed with the Ontario Gazette is the first indication of the Ministry’s response to the submissions.  At first glance it appears that 10 of the proposed changes were not adopted.

The three substances the Ministry proposed to raise the OEL’s (butane, 1-hexene, and TDI) have not been adopted.  Other proposals not adopted were:

• the inclusion of methane (proposed 1000 ppm) and natural gas (proposed 1000 ppm) into the list of OELs instead of being listed under simple asphyxiants (Part 9 of O.Reg 833);
• rosin core solder pyrolysis products not moved to the list of substances without an OEL ( Part 10 of O.Reg 833 substances to which any exposure should be avoided);
• sulphuric acid (proposed 0.2 mg/m3, current 1 mg/m3),
• refractory ceramic fibres (proposed 0.2 f/cc, current 1 f/cc),
• wheat flour dust (proposed 0.5 mg/m3, current 3 mg/m3), and
• crystalline silica (proposed 0.05 mg/m3, current 0.1 mg/m3). 

Due to the short time given to review the comments and the volume of comments on these substances the Ministry is taking more time to review these particular chemicals.

The previously scheduled changes to 1,3-butadiene and carbon monoxide which were to have taken affect in December 31, 2005, are now being adopted as of March 1, 2005. 

What will be the impacts of these changes be on Ontario workers?  The number of substances for which the OEL will be reduced is about 37, along with about 27 new OEL’s for substances not previously covered by the regulation for a total of 64 numerically significant changes.  Another 10 substances had designation changes but no change to the numerical OEL itself.  But will these changes on paper translate to real changes in actual workplaces?  Of the 37 substances for which the OEL has been lowered, the majority are not substances for which there is a lot of exposure in Ontario.  There are a number of solvents whose OEL has been lowered, but for most of these it is doubtful that employers will have to change workplace practices and/or exposure control to comply with these new solvent OELs.  The changes which stand to have the greatest impact, is the new asphalt OEL (0.5 mg/m³ down from 5 mg/m³) which may require the adoption of new control technologies.  The drop of the hydrogen chloride from 5 ppm to 2 ppm might also require some workplaces to review exposure conditions.  The reduction of manganese fume from 1 mg/m³ to 0.2 mg/m³ may require additional controls for heavy mild steel welding operations or manganese steel welding. 

The addition of inhalable natural rubber latex as total proteins at 0.001 mg/m³ may affect any workplace still using natural latex gloves.  Most of the other 26 new additions are rather uncommonly used chemicals and thus not likely to affect too many Ontario workplaces. 

The change in the butadiene OEL had been delayed from previous rounds of OEL updates in response to the rubber industry so it is anticipated that the industry expects some difficulty in achieving this new OEL.  The reduction of the carbon monoxide STEL from 400 ppm to 100 ppm, this may be difficult to achieve for forklift truck drivers unloading transports.  It is quite easy to exceed 100 ppm inside the trailer during loading or unloading.

Of the 10 substances OHCOW submitted comments on, four were not changed.  The comments regarding the three additional hazards not included in the proposed changes (wood dust, metalworking fluids and noise) were also not addressed.

For further information contact joudyk@ohcow.on.ca