United States may apply to the Accreditation Board for Engineering and Technology (ABET) to have their program accredited. As of October 1, 2006, 27 institutions have accredited their industrial hygiene programs. Accreditation is not available for Doctoral programs. In the U.S., the training of IH professionals is supported by National Institute for Occupational Safety and Health through their NIOSH Education and Research Centers. Professional credentials Australia In 2005, the Australian Institute of Occupational Hygiene (AIOH) has accredited professional occupational hygienist through a certification scheme. Occupational Hygienists in Australian certified through this scheme are entitled to use the phrase Certified Occupational Hygienist (COH) as part of their qualifications. Hong Kong Registered Professional Hygienist Registration & Examination Board (RPH R&EB) is set up by the Council of the Hong Kong Institute of Occupational & Environmental Hygiene (HKIOEH) with an aim to enhance the professional development of Occupational Hygienists and to provide a path for persons who reach professional maturity in the field of occupational hygiene to obtain qualification recognised by peer professionals. Under HKIOEH, RPH R&EB operates the registration program of Registered Professional Hygienist (RPH) and qualifying examination in a standard meeting the practice as recognised by the National Accreditation recognition (NAR) Committee of the International Occupational Hygiene Association (IOHA). United States Practitioners who successfully meet specific education and work-experience requirements and pass a written examination administered by the American Board of Industrial Hygiene (ABIH) are authorized to use the term Certified Industrial Hygienist (CIH) or Certified Associate Industrial Hygienist (CAIH). Both of these terms have been codified into law in many states in the United States to identify minimum qualifications of individuals having oversight over certain activities that may affect employee and general public health. After the initial certification, the CIH or CAIH maintains their certification by meeting on-going requirements for ethical behavior, education, and professional activities (e.g., active practice, technical committees, publishing, teaching). ABIH certification examinations are offered during a spring and fall testing window each year at more than 400 locations worldwide. The CIH designation is the most well known and recognized industrial hygiene designation throughout the world. There are approximately 6800 CIHs in the world making ABIH the largest industrial hygiene certification organization. The CAIH certification program was discontinued in 2006. Those who were certified as a CAIH retain their certification through ongoing certification maintenance. People who are currently certified by the ABIH can be found in a