The IOHA could not exist without the active participation and support of its member organisations , listed below:

Note - All organisations which have their own www site are identified with hypertext links, to allow the reader to jump directly to that page. To contact the IOHA representative for an organisation please see the list of Board Members

• American Conference of Governmental Industrial Hygienists ACGIH
• American Industrial Hygiene Association AIHA
• Australian Institute of Occupational Hygienists AIOH
• Belgian Society for Occupational Hygiene
• Brazilian Association of Occupational Hygienists (Associação Brasileira de Higienistas Ocupacionais, ABHO)
• British Occupational Hygiene Society BOHS
• Canadian Registration Board of Occupational Hygienists CRBOH / Conseil Canadien d'Agrément des Hygiénistes du Travail, CCAHT
• Dutch Occupational Hygiene Society  (Nederlandse Vereniging voor Arbeidshygiëne, NVvA)
• French Occupational Hygiene Society
• Finnish Occupational Hygiene Society (Suomen Työhygienian Seura, STHS)
• German Society for Occupational Hygiene (Deutsche Gesellschaft für Arbeitshygiene, DGAH )
• Hong Kong Institute of Occupational and Environmental Hygiene
• Italian Occupational Hygiene Association
• Japan Occupational Hygiene Association
• Japan Association for Working Environment Measurement (JAWE)
• Malaysian Industrial Hygiene Association
• Mexican Industrial Hygiene Association (Asociación Mexicana de Higiene Industrial - AMHI)
• New Zealand Occupational Hygiene Society NZOHS
• Norwegian Occupational Hygiene Association (Norsk yrkeshygienisk forening, NYF)
• Occupational Hygiene Society of Ireland OHSI
• Polish Association of Industrial Hygienists ( Polskie Towarzystwo Higienistów Przemysłowych - PTHP)
• Southern African Institute for Occupational Hygiene - Certification Board (SAIOH-CB)
• Swedish Association of Occupational and Environmental Hygiene (Svensk Yrkes- och Miljöhygienisk Förening, SYMF)
• Swiss Society for Occupational Hygiene (Schweizerischen Gesellschaft für Arbeitshygiene - SGAH / Société Suisse d' Hygiène du Travail - SSHT)
• Taiwan Occupational Hygiene Association (TOHA) 

Organisations wishing to join IOHA should contact the IOHA Secretariat with the following information:

1. The full name of their Organisation/Association/Society.
2. Full contact details of their contact person during the application stage (name, address, phone/fax, email etc.).
3. The number of members in their Organisation/Association/Society.
4. Details of the different grades of membership (if any).
5. How personnel are selected to those grades.
6. Any rules, byelaws, constitutions etc. that they may have (in English).
7. A written confirmation that the Organisation/Association/Society will accept and subscribe to the objectives of IOHA, and accept and be bound by IOHA's byelaws.