TOXNET  
   Provides access to a cluster of databases on toxicology, hazardous chemicals, and related areas. Instruction manuals are included.
   http://toxnet.nlm.nih.gov/

Worksafe:Occupational Safety and Health Resources  
   A statewide coalition of individuals and organizations dedicated to promoting safety and health in the workplace in order to preserve the health of all Californians. The coalition includes labor and community groups as well as individual workers, occupa
   http://www.worksafe.org/

American Industrial Hygiene Association  
   The AIHA is "..dedicated to the anticipation, recognition, evaluation, and control of environmental factors arising in or from the workplace that may result in injury, illness, impairment, or affect the well-being of workers and members of the commun
   http://www.aiha.org/

ACGIH  
   An association of health and safety professionals devoted to protecting the health of the American worker and the environment. It supports the industrial hygiene profession in the anticipation, recognition, evaluation, and control of job-site hazards that
   http://www.acgih.org/

The Health and Safety Executive  
   Ensuring that risks to people's health and safety from work activities are properly controlled. Available resources, publications, and leaflets. (UK)
   http://www.hse.gov.uk/

British Occupational Hygiene Society (BOHS)  
   "The aim of the Society is to promote the science of occupational hygiene by raising awareness of the value of the speciality through education, information exchange, research and professional networking."
   http://www.bohs.org/

International Occupational Hygiene Association (IOHA)  
   Provides an international voice of the occupational hygiene profession through its recognition as a non-governmental organization (NGO) by the International Labour Organization and the World Health Organization. Conducts a wide range of activities intende
   http://www.ioha.com/

Technical Guide to Direct Reading Devices  
   Free online technical guide from the British Occupational Hygiene Society on DRDs used to monitor the atmosphere for airborne pollutants, which can be present as gases, vapours, aerosols or fume.
   http://www.bohs.org/pubs/library/tg15/