The list

The Air Contaminants Benchmarks List itemizes approximately 5,100 contaminants with corresponding benchmarks (standards, guidelines or screening levels), used by facilities to assess their contributions of a contaminant to air. This information is primarily used to complete an Emission Summary and Dispersion Modelling (ESDM) report under Ontario Regulation 419/05 or Ontario Regulation 1/17.

Download current list (XLSX)


The list contains two types of benchmarks:

  • Benchmark 1 (B1) values (standards and guidelines)
  • Benchmark 2 (B2) values (screening levels)

B1 value

If a B1 value is exceeded, the facility is required to carry out specific actions. See section 28 of Ontario Regulation 419/05 for actions.

B2 value

If a B2 value is exceeded, or if no B2 value is available, the regulations require potential adverse effects to be assessed.

Previous versions

Download a previous version of the list from January 2017

In 2017, the Air Contaminants Benchmarks List replaced these documents:

  • Summary of Standards and Guidelines sorted by Chemical Abstracts Service (PIBS # 6569e01)
  • Summary of Standards and Guidelines sorted by Chemical Name (PIBS # 6569e01)
  • Jurisdictional Screening Level (JSL) List - A Screening Tool for Ontario Regulation 419 (PIBS # 6547e)