Guide and computer-based tools for the adjustment of PEVs for unusual work schedules, 3rd edition, revision based on ROHS 2007 Abstract Because of recent changes to the Regulation respecting occupational health and safety (RROHS), the IRSST had to adapt the Guide for the adjustment of permissible exposure values for unusual work schedules that it publishes for Québec professionals in this field, as well as the computer-based tool allowing its application. This work has update toxicological knowledge about the substances targeted by regulatory changes and determine the pathology codes and adjustment categories for the new substances included in the RROHS. The guide’s updating helps provide better health protection to workers exposed to these contaminants and having unusual work schedules. Produced Under this Project Guide and Tools Guide for the adjustment of permissible exposure values (PEVs) for unusual work schedules Technical guide: T-21, T-22 Additional Information Type: Project Number: 0099-6920 Status: Completed Year of completion: 2008 Research Field: Chemical and Biological Hazard Prevention Team: Daniel Drolet (IRSST)Adolf Vyskocil (Université de Montréal)Thierry Petitjean-Roget (IRSST)