Recommended Exposure Limit : The highest allowable airborne concentration that is not expected to injure a worker. Expressed as a ceiling limit or as a time weighted average, usually for 10-hour work shift
University of Michigan-Flint, Environment Health and Safety Department, MSDS Glossary, University of Michigan-Ann Arbor, Michigan USA 2015, MSDS Terms Glossary is from the University of Oklahoma EHS Department website 2006. http://www.umflint.edu/sites/default/files/groups/ Environment__Health_and_Safety_Department/msds_glo ssary.pdf, (MSDS - Amer) {911}