ACS Safety in Academic Chemistry Laboratories: Best Practices for First- and Second-Year University Students (8th ed. PDF): a great open access manual by the American Chemical Society.
Publications & Resources by ACS Committee on Chemical Safety: The committee promotes and facilitates safe practices in chemical activities for all levels of audiences, and the publications/resources provided are for the public, elementary school, high school, undergraduate/graduate, and lab researchers/workers.
Health Canada Environmental and Workplace Health: offers information and advice on some of the most common environmental factors that affect human health: air, noise, soil and water pollution, climate change, environmental contaminants, occupational health and safety.
Labour Canada Workplace Health and Safety Links: includes links to CSA Standards for Occupational Health and Safety, and Compliance Policy, etc.
CanOSH - Canada's National Occupational Health and Safety Web Site: puts together workplace safety and health information from the Canadian federal, provincial and territorial governments.
TOXNET: United States National Library of Medicine (NLM) Databases on toxicology, hazardous chemicals, environmental health, and toxic releases.
WHO Chemical Safety: includes fact sheets, Global Health Observatory: statistics on chemicals, and WHO programs and activities related to chemical safety.
Centers for Disease Control and Prevention Chemical Safety: provides a cumulative list of chemical databases, which contain acute and chronic health effects information of being exposed to a myriad number of hazardous chemicals.
US Chemical Safety Board: The CSB is an independent US federal agency charged with investigating industrial chemical accidents.
OECD Chemical Safety and Biosafety: covers guidelines for the testing of chemicals, good lab practice, legal recommendations and decision, and more; also provides Directories and Databases of Chemicals and Biosafety