In late 2010 there were amendments to the Regulation 833, Control of Exposure to Biological and Chemical Agents
, that were not well communicated by the Ministry of Labour. As a result, there has been some confusion among Workers Health & Safety Centre-qualified instructors and staff.
On November 5, 2010, regulation 419/10 amended the biological and chemical agents regulation. Before the amendment, approximately 800 substances were listed in the regulation along with any applicable occupational exposure limits. These substances and their limits were printed in Table 1.
The amendments created two tables
— the Ontario Table and the ACGIH (American Conference of Governmental Industrial Hygienists) Table.
The Ontario Table, which includes less than 100 substances, is printed as Table 1 of the Bio/Chem Agents regulation. The limits for these substances can be checked by looking at a printed copy or the e-laws version.
The ACGIH Table is not printed in the regulation. The regulation adopts by reference the “Adopted Values” table on pages 10 to 61 of the ACGIH publication 2009 Threshold Limit Values and Biological Exposure Indices. Because the ACGIH table is adopted by reference, the limits in the ACGIH document are enforceable. The exception is that if a substance is listed in both the Ontario Table and the ACGIH Table, the limits in the Ontario Table apply.
Unfortunately, the ACGIH does not provide free access to their tables. However, the Ministry of Labour has posted a combined table listing all substances and limits from both tables at http://www.labour.gov.on.ca/english/hs/pubs/oel_table.php