ACGIH 21 : American Conference of Governmental Industrial Hygienists. The Threshold Limit Value (TLV) Committee and Ventilation Committee of the ACGIH publish exposure guidelines which are used worldwide
Canadian Centre for Occupational Health and Safety CCOHS, Chemicals & Materials Safety Data Sheet MSDS - An Explanation of Common Terms, Ontario, Canada 2013. http://www.ccohs.ca/oshanswers/chemicals/glossary/ msds_gloss_a.html, (Common MSDS Terms Used in Occupn Hlth and Sfty - Canad) {630}