Since long, St. John's wort has been recognized by people for the health benefits possessed by the herb. For instance, it possesses wonderful anti-viral as well as antiseptic characteristics and is also effective when used as an analgesic.
Occupational Exposure Limits (. s) restrict the amount and length of time a worker is exposed to airborne concentrations of hazardous biological or chemical agents.here are. s for over 725 substances under R.R.O. 1990, Regulation 833 (Control of Exposure to Biological or Chemical Agents) and Ontario Regulation 490/09 (Designated Substances) under Ontarioâs Occupational Health and Safety Act.
1 A Short Term Exposure Limit (STEL) is defined by ACGIH as the concentration to which workers can be exposed continuously for a short period of time without suffering from: 2  irritation. 3  chronic or irreversible tissue damage.