The International Occupational Hygiene Association (IOHA) is an association of occupational hygiene organisations from across the world and represents the global community of occupational hygienists. Since its creation in 1987, IOHA has grown to 38 member organisations, representing over 20,000 occupational hygienists worldwide.
Aims of IOHA

IOHA aims to improve, promote and develop the practice of occupational hygiene throughout the world so as to improve and protect worker health and well being.
Since 2000, IOHA operates a National Accreditation Recognition programme to promote global respect for and recognition of professional certification programmes which meet or exceed the "IOHA Model Certification Programme." IOHA is a non-government organization, recognized by the International Labour Organization and the World Health Organization
To learn more about the work of IOHA and its membership, visit the IOHA website or attend an IOHA conference.
OHTA-IOHA Agreement
OHTA has committed to support IOHA in promoting the development and implementation of a common international framework for occupational hygiene training.
IOHA has consented to the use of the IOHA logo with the statement “Supported by IOHA” on OHTA certificates, website and training documentation.
OHTA and IOHA are working together to provide formal recognition of the qualifications delivered by the OHTA training programmes.
Since 2015, OHTA’s constitution has been linked to IOHA through its member associations. All member associations of IOHA are entitled to apply for membership of OHTA. Each association that is accepted as a member of OHTA appoints a representative to act as liaison and vote at general meetings.
IOHA also appoints a representative to be a director on the OHTA Board.