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 following table shows the health effects of different Air Quality Index (AQI) levels caused by total reduced sulphur compounds.

Health effects of different Air Quality Index (AQI) levels caused by total reduced sulphur compounds
Category	AQI	Pollutant Concentration Breakpoints (ppb)	Total Reduced Sulphur (TRS) Compounds
Very Good	0 - 15	0 - 5	No health effects are expected in healthy people.
Good	16 - 31	6 - 10	Slight odour.
Moderate	32 - 49	11 - 27	Odour.
Poor	50 - 99	28 - 999	Strong odour.
Very Poor	100 or over	1000 or over	Severe odour; some people may experience nausea and headaches.

Note: ppb = parts per billion.