Total Reduced Sulphur Compounds (TRS)

What are total reduced sulphur compounds?

TRS compounds produce offensive odours similar to rotten eggs or cabbage.

What are the sources of TRS?

Industrial sources of TRS include the steel industry, pulp and paper mills, refineries and sewage treatment facilities. Natural sources include swamps, bogs and marshes.

What are the effects of TRS?

TRS compounds are not normally considered a health hazard. They are, however, a primary cause of odours.

The Ontario Ambient Air Quality Criteria (AAQC) for 1-hour average TRS concentrations is 27 parts per billion (ppb), which has been incorporated into Ontario’s Air Quality Health Index to better protect Ontarians. For more information on how the Air Quality Health Index has been modified for reporting in Ontario, please visit the Frequently Asked Questions.