SAMANTHA CONNELL, CIH, is the global health programs director at Indorama Ventures PCL and president of the International Occupational Hygiene Association.

Acknowledgements: The author would like to thank those who contributed or reviewed content, including Maharshi Mehta, Dooyong Park, Haruo Hashimoto, Andrea Hiddinga, and Thomas Fuller.
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The Widespread Need for Occupational Hygiene
Author’s note: In the context of this article, industrial hygiene and occupational hygiene are synonymous, and both will be referred to as “OH.” While the International Occupational Hygiene Association is the source for much of the information shared here, this column aims to address the global OH situation more broadly.

The International Occupational Hygiene Association represents a community of more than 20,000 occupational hygienists and individuals from other occupational health and safety disciplines from 42 member organizations across the globe. As IOHA works to improve, promote, and develop occupational hygiene worldwide, it is well positioned to help make clear the international needs for and of the OH profession.
The needs of the field and practitioners vary by country and, in some cases, regionally. In general, occupational hygienists can find strong support among fellow OH community members within their regions. Regional networks include professional organizations like the Asian Network for Occupational Hygiene, the Pan-American Occupational Hygiene Network, and the European Platform for Occupational Hygiene. These groups are key when it comes to understanding regional OH needs or conducting region-wide projects.
NUMBER OF PROFESSIONALS AND CERTIFICATIONS The need for qualified occupational hygienists is enormous. Globally, about 2.3 million lives per year are lost due to work-related accidents and illnesses. The International Labor Organization (ILO) estimates that occupational diseases account for approximately two million, or 86 percent, of the lives lost. According to an estimate made by IOHA’s National Accreditation and Recognition (NAR) Committee, 44,000 qualified occupational hygienists are needed globally. Based on IOHA data, approximately 20,000 occupational hygienists are available globally, with only 8 percent located in the top 10 emerging economies like India and China, where there is a strong need.
Map of IOHA member organizations as of October 2023. Visit IOHA’s website for a larger, interactive version of this map. Image credit: IOHA.
On the map above, the blue shading on the countries depicts population density as of 2023. The green overlay indicates countries with an IOHA member organization. Click or tap the map image to open a larger version in your browser. Image credit: IOHA.
Encouraging national accreditation schemes or schemes within regions is important. Candidates who want to become certified in another country or accreditation scheme often must learn country-specific legislation or references that may not be necessary in their area of practice. They may also face a language barrier. IOHA’s NAR committee was established to support the recognition of national accreditation schemes on a global level. The committee recognizes national occupational hygiene associations that offer certification examinations and works toward filling the need for qualified occupational hygienists. Today, there are 18 NAR accreditation schemes representing more than 8,100 certified professionals across the world. Additional certification schemes that do not belong to NAR—ABHO in Brazil, for example—also recognize certified professionals. The Board for Global EHS Credentialing (BGC) is a NAR member and represents approximately 83 percent of certified hygienists with global recognition. This means that Certified Industrial Hygienists are certified by an NAR member.
The most recent NAR member is the Iberoamerican Board of Occupational Hygiene (JIHO). JIHO was formed with the goal of creating the first OH certification exam in Spanish. The candidate requirements and exam are similar to that of BGC’s CIH but are entirely in Spanish. The first exam was given in May 2023. By September, there were 13 new CIHs from various Spanish-speaking countries, including Guatemala, Peru, Argentina, Mexico, Colombia, and Spain.
Local or national schemes may positively impact the OH field by becoming part of policy. For example, the Japanese government began drastically changing its policy on the management of chemicals in 2021. It shifted from a method of having employers follow specific regulations to a method of setting regulatory occupational exposure limits and achieving them through employers’ self-directed efforts. To facilitate the new policy, the government officially recommends the local OH qualification, which is recognized by IOHA. While the Japan Association for Working Environment, the country’s credentialing body, had been receiving a stagnant number of applications since the qualification was first offered in 2010, the new policy is encouraging rapid growth. The country had 16 qualified occupational hygienists in 2015, 45 in 2021, and 80 as of this year.
EDUCATIONAL OPPORTUNITIES Affordable education and training represent another significant need as the education framework for OH varies globally. Whereas some countries have models similar to that of the U.S., with technician-level training as well as university-level, others only have post-graduate certificates or diplomas with the base of education in other areas of study. And still more countries mainly have access to OH training through programs such as the Occupational Hygiene Training Association’s (OHTA) international training scheme or training available from other providers like OSHNet School.
Professional and grassroots organizations worldwide—including national professional organizations and local sections of larger organizations, Workplace Health Without Borders, and more—provide a variety of continuing education opportunities. Many IOHA member organizations and some of the regional groups listed previously host annual conferences where professional development courses are also offered. Many of these groups regularly conduct webinars and some even provide OHTA courses on a volunteer basis, with minimal fees to cover course costs. And, of course, bachelor’s and master’s programs in OH are another option around the world. A list of OH education and training options is available on the IOHA website. Please contact IOHA to submit additional opportunities to the list.
THE PATH FORWARD From a global perspective, the needs of our profession vary widely. However, certain priorities—for example, improving visibility—unite occupational hygienists worldwide. We must continue a two-fold approach to promote our profession: first, to gain recognition for the OH field as experts and for inclusion in legislation; and second, to attract new professionals.
Even in developed economies, small and medium enterprises struggle to fulfill their duties to protect workers. In some countries, workplace health (and potentially even safety) isn’t explicitly mentioned in legislation. Therefore, occupational hygienists can’t currently rely on basic compliance to achieve worker protection. And while legislation that requires employers to commit to OHS and calls for regular workplace inspections is perhaps a key part of achieving healthy workplaces, compliance should not be the only answer. In parallel to working toward recognition in legislation, it is imperative that occupational hygienists communicate and “sell” the benefits of good workplace health so that employers want to protect workers beyond compliance.
An Update from ILO
In June 2022, the International Labor Organization (ILO) Declaration on Fundamental Principles and Rights at Work was amended to include “a safe and healthy working environment” as a fundamental principle and right at work. With that, the International Labor Conference—also called an international parliament of labor—decided to designate the Occupational Safety and Health Convention, 1981 (No. 155) and the Promotional Framework for Occupational Safety and Health Convention, 2006 (No. 187) as fundamental conventions. According to ILO, these conventions “describe the core principles and rights in the field of occupational safety and health and serve as the basis for the more advanced safety and health measures described in other OHS instruments.”
As a result of these changes, all members of ILO are now expected—even if they have not ratified Conventions 155 and 187—to promote and realize the principles concerning individuals’ right to a safe and healthy working environment. Of the 187 ILO members states, only 78 and 61 have ratified Conventions 155 and 187, respectively.
ILO will support members to respect and realize these conventions, but ultimately countries will need to adapt their national policies and bring competent professionals onboard to help them achieve this feat. The International Organization of Employers (IOE) recommends that employers get involved in debates on the topic, know the scope of the conventions, prepare strategies, and start building capacity for businesses, including small and medium enterprises. Within the workplace, IOE urges employers to ensure that internal policies and practices are in place and to develop relevant communication strategies. Nations and businesses alike will need to employ OHS professionals to ensure successful implementation.
Even with legal requirements or companies’ increased desire to hire hygienists, there are still not enough professionals to fill the needed roles. The U.K., the U.S., Australia, and the Netherlands have some of the best ratios of workplace health protection experts to working population, but even in these regions, IOHA estimates that the ratio is less than 1 expert per 50,000 workers. Continuing to educate OHS professionals and training new occupational hygienists is paramount when it comes to filling these gaps.
It’s also important to increase our visibility and communicate the value of OH in order to become key contributors in governments, corporations, and academic institutions. We want these organizations to seek our input and understand how OH can inform decision-making.
As a profession, we should take advantage of technological advances. In doing so, we should also consider advancements that make technology more affordable and easier to use in remote locations. As technology changes, occupational hygienists will need to adapt methodologies and ways of working to keep up with the possibilities offered by technology as well as varying working conditions across the globe. Exposures are different in today’s world, with workers frequently changing jobs, potentially having high exposures for short durations, and moving more often. As we advance with new technologies—and potentially new stressors—we must remain vigilant and anticipate new hazards. At the same time, we cannot assume that "traditional hazards" no longer require us to monitor related exposures.
CALL TO ACTION We need more focus on collaboration and sharing knowledge, practices, and research developments across sectors, countries, and regions. This collaboration will allow us to reduce duplicated efforts, act on new developments more quickly, and make advancements for worker health. If you’re intrigued by the global landscape of OH and want to help advance the field worldwide, please contact the AIHA International Affairs Committee, IOHA, or any of the other organizations mentioned in this article.

ILO: “A Safe and Healthy Working Environment Is a Fundamental Principle and Right at Work.”
ILO: World Statistic: “The Enormous Burden of Poor Working Conditions.”
International Organization of Employers: “Occupational Safety and Health as a New Fundamental Principle and Right at Work: Guidance for Employers” (December 2022).
IOHA: Member Organizations.
IOHA: National Accreditation Recognition (NAR) Committee.
IOHA: OH Education and Training.