Health Canada and the Committee on Drinking Water have published new proposed guidance for benzo[a]pyrene in Drinking Water. 

 

The existing guideline on BaP, last updated in 1986, based its maximum acceptable concentration of 0.01 µg/L on an increased incidence of gastric tumours in mice. However, flaws in the design of this study were identified. This new document identifies forestomach tumours in mice as the critical endpoint on which to derive the proposed MAC of 0.04 µg/L, based on a weight of evidence approach. It provides updated data and information related to exposure to benzo[a]pyrene in Canada and take into consideration analytical and treatment limitations.

 

Based on this evidence a new maximum acceptable concentration (MAC) of 0.000 04 mg/L (0.04 µg/L) is proposed.

 

Health Canada is consulting on:

1. the proposed guideline;
2. the approach used for its development;
3. the potential economic costs of implementing it;
4. the ability of accredited laboratories to reliably measure benzo[a]pyrene at or below the proposed maximum acceptable concentration; and
5. to determine the availability of additional exposure data.