Benchmarks on the ACB List
Standards and Guideline Values
All existing standards and guidelines have been consolidated on to the ACB List, replacing the previous documents: Summary of Standards and Guidelines sorted by Chemical Abstracts Service (PIBS # 6569e01) and Summary of Standards and Guidelines sorted by Chemical Name (PIBS # 6569e01). Existing ministry processes for development of standards and guidelines and associated consultation processes remain unchanged.
Jurisdictional Screening Levels
JSLs reflect concentrations at which contaminants are not likely to cause an adverse effect (i.e., when the concentration is no greater than the screening level). Exceedence of a JSL does not necessarily mean that a concentration is of concern but does trigger the need for further study to assess the potential for an adverse effect.
In 2008, the ministry set over 1200 JSLs through a review of limits in other jurisdictions. These screening levels have been added to the ACB list, replacing the document: Jurisdictional Screening Level (JSL) List - A Screening Tool for Ontario Regulation 419 (PIBS #: 6547e).
The ministry will be consulting with stakeholder on adding more screening levels to the list based on reviews of toxicity information and current limits in other jurisdictions. The consultation will focus on providing a transition period for the more stringent updated screening levels.