TLV-TWA 1 : The allowable Time Weighted Average concentration for a normal eight hour workday or 40 hour work week. May also be adjusted for extended work shifts. See also: Short Term Exposure Limit (STEL)
The Association of Petrochemicals Producers in Europe (APPE), The European petrochemical industry, Glossary of Terms on Chemical Safety for Use in IPCS Publications, van Nieuwenhuyse, Brussels 2006. http://www.petrochemistry.eu/glossary.html, (Petrochem Ind - Brit) {473}