How do I apply for a course?

Courses in your area can be found under Find Courses in the Training Resources section of the website. You can search by Topic, Level, Language, Country and Start Date. The course information will include contact details for the training provider. Follow their instructions as to how to enrol.

Alternatively search our directory of Approved Training Providers by clicking on Find Training Providers, also in the Training Resources section. You can search by the modules the provider is approved to run, the countries where the provider is approved to deliver courses, and the languages the provider teaches in.

How do I become qualified?

On the “Learn” tab at the top of the home page, scroll down to Training Scheme and Qualifications Framework and click on any of the four qualification levels. Read the information available, decide your level of interest and search for a course or contact an approved provider in your area to see when you can enrol in individual courses.

Can I study by myself then just take the examination?

OHTA training courses are designed to teach you practical skills which are hard to learn by yourself. They also help you to establish contacts with other occupational hygienists. The assessment process does not just consist of an examination: informal assessment exercises are conducted throughout the course so that students can be helped to overcome any difficulties. Most students will find it beneficial to attend a course.

However, we recognise that this approach cannot suit everybody, so there are alternative ways to achieve the training and qualifications that lead to the International Certificate in Occupational Hygiene (ICertOH). These are:

  • Self study or use of online training versions of courses that are offered by at least one university.
  • By taking an approved university degree course which OHTA and the OHTA Awarding Body have determined provides exemption from studying the modules. More information is available on the BOHS website.

The student may need to complete some additional form of assessment such as a Personal Learning Portfolio and attendance at an interview.

How can I become an approved training provider?

Only approved providers are allowed to offer courses leading to the international qualifications. The criteria for approval and application form can be found in the “Train” section of the website under Become An Approved Training Provider. For further information, contact OHTA at

How much does the International Certificate cost?

Approved training providers charge a fee for you to attend each course. That fee may include a charge for you to sit the examination for that subject or the provider will advise you of the examination fee, which will be collected by the provider on behalf of the awarding body. The awarding body also charges a fee for the final two components of the pathway to the International Certificate: submission of the Personal Learning Portfolio and an oral examination.

Who can I talk to if I don’t understand the process and procedures listed on the website?

OHTA is run by volunteers with part-time administrative support so the best way to contact us is by email. If you have a specific question please contact and we will respond to you as quickly as possible.

How do I complain about something on

The Board of OHTA takes all complaints and comments seriously. Please take the time to inform us of your concerns by emailing the Board at

Alternatively please use the Feedback form available on this website.

Where can I find out more about copyright and licensing of materials?

All training materials on are covered under one of two Creative Commons licence arrangements. Please follow the Creative Commons link to read more on this topic.

How do I report a copyright violation?

Please send an email to and your concern will be investigated.

How do I find out about setting up a national occupational hygiene association in my country?

Contact IOHA direct or send an email to More information on IOHA can be found here.

I am responsible for occupational hygiene in a large organisation. Can you advise how I can use the scheme in my company or organisation to train people in occupational hygiene?

Many large organisations use this scheme for training and development. The modules are often built into a career development structure such as the one shown below.

Alesbury. R.J and Bailey.S.J
Ann Occup Hyg (2014) 58 (2)
: 140-151

If you would like to know more we will ask a volunteer to contact you individually to discuss. Please send an email to

How can a University use the scheme in academic programmes?

The OHTA modules are being used by a number of Universities in academic programmes leading to the award of BSc or MSc degrees. To find out more please send an email to

How can I get a translation of the web pages

This site uses the weglot plug-in providing automatic translation into French, Spanish, Portuguese, Hindi or Simplified Chinese. In the bottom right hand corner of the screen, click on the language you prefer, and the page will be automatically translated.

Alternatively, in any browser you can use Google® Language Tools to view a web page in a wide range of languages.

If you are using Microsoft Internet Explorer® on Windows Vista or Windows 7® you can right click the page in your browser and select Translate with Bing®.

How do OHTA modules fit into a comprehensive model of OH education and training?

OHTA provides a comprehensive framework for education and training in occupational hygiene, supported by the international occupational hygiene community. The OHTA framework does not replace or compete with existing education and training courses, rather it includes and builds on them, integrating them all into a coherent framework for career development.

OHTA currently supports learning at four different levels. These levels align with the training needs that have been identified by industry. For more information go to the "Learn" tab and click on Training Scheme and Qualifications Framework.

Awareness materials are introductory information for employers and employees who need to know about the hazards in their workplaces and how they are controlled to provide a safe environment. This part of the scheme is still at an early stage of development. When it is complete, people will be able to learn about hazards such as silica, asbestos, lead and noise in practical workplace situations. The materials will be mainly for self-study, though they can be taught if needed.

The Foundation level is anchored on a 5-day taught module that introduces the basics of occupational hygiene. It explains how to identify health hazards in the workplace, how to assess the risks that they pose, when exposure measurements might be needed, and how control measures can be selected and tested. The course is suitable for people from related fields such as safety and occupational health, as well as for managers and engineers who need a more in depth understanding than just awareness. It also provides a foundation for studying occupational hygiene at the higher levels. People taking the course receive a certificate of successful course completion from OHTA.

The Intermediate modules are designed for occupational hygiene technical staff. These are the people who might measure exposure levels to chemicals or noise, or who might test ventilation systems to see if they are effective. The training is focused on the practical aspects of occupational hygiene, which were rated as extremely important by both students and employers. Students who successfully pass six intermediate modules can apply for the International Certificate in Occupational Hygiene (ICertOH)by submitting a portfolio of their experience and taking an oral exam. The examinations and awards are provided by an OHTA Awarding Body.

The training modules at Foundation and Intermediate levels are delivered through a network of approved training providers including consultancies, not-for-profit organisations and universities. It is important to mention that these organisations do charge the students (or their employers) their normal rates for delivering the training, so attending a training course is not normally free. OHTA does not derive any income from the training events.

For people aspiring to become hygiene professionals, Specialist qualifications are needed. Occupational hygiene professionals are specialists with responsibility for designing and delivering the occupational hygiene programmes in a workplace.

OHTA is currently developing specialist modules for hygienists in particular industries. There is no formal qualification; instead training providers are invited to produce their own assessment as needed. Some of these specialist modules can be integrated into Masters degrees.

At the top of the career ladder, senior occupational hygienists operating at management levels within large organisations or in consultancies need to have leadership skills in addition to mastery of the technical and professional skills. They will need additional training in areas such as management, communication and finance. We have yet to develop materials at this level.

How do OHTA courses affect academic training in occupational hygiene?

Academic programmes are essential to underpin the science of occupational hygiene through research and teaching.

The lower levels of the OHTA framework (Awareness, Foundation and Intermediate) are designed to raise awareness and teach practical skills to encourage more people to get involved with occupational hygiene. This should eventually result in more students wanting to study academic programmes.

Several of the OHTA modules were developed on our behalf by universities. OHTA also works with universities to develop and improve academic programmes. OHTA has already contributed to the introduction of two new Masters courses, with classroom based courses at the universities of Wollongong in Australia and Antofagasta in Chile, plus a distance learning programme run by UIC (Chicago, US). We are particularly keen to ensure that academic programmes do provide an adequate foundation in practical skills, so that graduates are able to practise occupational hygiene and are not just theoreticians.

Why does OHTA not require any entrance qualifications?

It is fundamental to OHTA that we want to encourage people to study occupational hygiene and not to put artificial barriers in their path. There are many ways that people can acquire the background knowledge and skills needed for study of occupational hygiene and we believe it would be wrong to discriminate based on some arbitrary entrance criteria. In this policy, we are following other progressive organisations such as the UK’s Open University, which focus on outcomes.

Therefore, there are no formal entry requirements for OHTA courses. If you have not studied before you may find it helpful to do some preparatory work before starting study, in order to develop a suitable level of study skills. Knowledge of mathematics, statistics, chemistry, engineering and biology are needed in a number of courses. We provide and signpost students to suitable materials that can be used for background study. We particularly recommend that students who are new to occupational hygiene study the Basic Principles course before embarking on the Intermediate modules. Students will also benefit from being employed in an appropriate setting and having the support of their employer.

The absence of entry requirements does not in any way imply a lower standard for OHTA training. OHTA qualifications are rigorously quality assured and are scrutinised by an Awards & Qualifications Committee with representatives of many of the major national examining boards in occupational hygiene.

What impact do the intermediate modules have on the professional status of occupational hygienists?

There has been long-standing confusion over the use of the term “occupational hygienist”. For some people, the term is reserved for those with specialist qualifications recognised by a professional body (e.g. CIH). More commonly, however, it is used to mean anyone working in occupational hygiene, with or without qualifications.

The OHTA framework clearly differentiates the various levels of training and ability. The International Certificate in Occupational Hygiene (ICertOH) is for those technical staff who are qualified to conduct practical occupational hygiene assessments and checks. People who wish to progress to full professional qualifications will need to study at the Advanced (Academic) level and to seek accreditation from their national IOHA-recognised professional body. As these schemes are well established, OHTA itself does not offer full professional accreditation.

How are the course fees established?

Course fees are set by Approved Training Providers and vary between providers and between countries. OHTA charges Approved Training Providers a modest levy which is payable for each student taking an OHTA examination. Other than that OHTA does not get involved in setting prices. Examination fees are set by the awarding bodies, not by OHTA.

We recognise that price is an issue in many countries. We also acknowledge the need of training providers to earn their living and examination boards to cover their costs. We hope that over time, competition between providers will lead to lower costs. We work with partners such as Workplace Health Without Borders (WHWB) to find ways to deliver training in developing countries where normal commercial costs are not viable. We also encourage provision of scholarships and bursaries where possible.

We believe that this policy on pricing is the best way to ensure that occupational hygiene training becomes sustainable in the long term.

What is our policy on using commercial training providers?

OHTA does not discriminate between training providers on the basis of their commercial status. Our criteria for approving training providers are based only on their capability to deliver the training. We encourage all professional hygienists to deliver training, whether they work in academia or industry, consultancy or a not-for-profit organisation.

We believe this approach is essential to ensure that as many people as possible benefit from occupational hygiene training. It is also fair to the training providers and in the long term will lead to a sustainable supply of occupational hygiene training.

Who makes a profit from OHTA?

OHTA is a registered UK charity (charity number 1168722) and is run largely by unpaid volunteers. Administrative support is provided through a contract with the national association BOHS, and other voluntary support from national associations such as AIOH and AIHA.

We make no charges for accessing or downloading materials from our site Costs that we incur for expenditure associated with the development and maintenance of courses are borne by donations from IOHA, AIHA, AIOH, BOHS and sponsorship from commercial partners that share our aims.

Course fees are set by the training providers not by OHTA. We do, however, make a modest levy on Approved Training Providers based on the number of their students who take OHTA qualifications. This is necessary to cover the limited operating costs that we incur in contracting paid staff to provide services and maintain standards.

The courses are delivered through a network approved training providers including consultancies, not-for-profit organisations and universities. It is important to mention that these organisations do charge the students (or their employers) their normal rates for delivering the training, so attending a training course is not normally free. As with any training, there are costs associated with the time provided by tutors, the facilities and other items, as well as the OHTA course levy previously mentioned. Training providers need to recover these costs somehow, usually in student fees. OHTA does not involve itself with the training providers’ commercial models but as the programme gains acceptance around the world, more training providers are signing up and our expectation is that competitive pressures will keep costs down. There are also some training providers that provide places free or at cost.

What are the limitations of OHTA and how does the leadership respond to identified issues?

Both the strengths and the limitations of the OHTA system arise from the way it evolved. The OHTA framework was developed by a group of senior occupational hygienists from multinational organisations following several years of consultation with fellow professionals, IOHA, national associations, academics, and others. It may not be perfect but the system that has evolved is one that has received overwhelming support from these stakeholders. It has at its core a simple model that can provide training at different levels where and when needed. It does not replace or compete with existing education and training courses, rather it includes and builds on them, integrating them all into a coherent framework for career development and providing practical training where otherwise it may not exist. It is supported by the international occupational hygiene community.

The development of training materials and courses to support the framework is resource constrained and there are currently gaps and limitations. Also, at present all the programmes are designed for face-to-face delivery. More flexible delivery methods will be needed to achieve our aim of reaching the largest possible audience. We would like to be able to add more video and photographic material, interactive online programmes and many other features.

OHTA aims eventually to support learning at five different levels. These levels align with the training needs that have been identified by industry. Materials are still being developed and not all of the levels have training materials in place as yet.

OHTA fully recognises the need to listen to the views of stakeholders and the scheme will evolve to reflect changing requirements as funding and resources becomes available. Areas that are under active consideration to enhance the scheme and current limitations include: translation of existing modules and the OHTA website into additional languages; provision of a wider range of modules, such as safety; provision of modules at levels other than foundation and intermediate and use of other means of delivery such as distance learning.

We welcome feedback on the OHTA scheme which can be given through the feedback form on this website or by email to

How does OHTA recognise and include other sources of reliable occupational hygiene training?

The OHTA scheme does not replace or compete with existing education and training courses, rather it includes and builds on them, integrating them all into a coherent framework for career development. For example, a student could choose to take the International Certificate in Occupational Hygiene (ICertOH) and then progress to take a Masters degree at a university before obtaining professional accreditation from a national body. The same student might also opt to study by traditional routes without taking any OHTA courses, and could still obtain the professional certification.

A key advantage of the OHTA scheme is its recognition across the world by IOHA, national associations and employers as a benchmark for building occupational hygiene capability. OHTA qualifications therefore have a high degree of transferability between countries and employers. Increasingly, countries are aligning their own training programmes with the OHTA framework and courses. In some parts of the world other routes of training and development are available but, by and large, there are relatively few programmes aimed at building practical occupational hygiene skills. Plugging the gap was a key reason the scheme was developed.

Other sources of good occupational hygiene training are available and we encourage users to look at all their options and decide for themselves which best suits their requirements.

One of the reasons for course material being made available through and for insistence that all Approved Training Providers have as course directors occupational hygienist professionally accredited through an IOHA recognised scheme, is to ensure courses are technically correct and instruction is delivered by those with practical experience. When the founders of OHTA were looking at options for global training, they found that some courses being offered were technically inappropriate and/or being taught by individuals with no experience of occupational hygiene. OHTA therefore has a strict programme of peer review and quality assurance for all OHTA courses leading to qualifications.

Where requested, OHTA is willing to work with training providers to explore additional options. However, our resources for such work are limited. We also recognise that there is more that can be done in this area.

How do OHTA communications present a balanced picture of the organisation’s current status?

As with any organisation we aim to communicate the benefits of our programmes. In line with nearly all other organisations we do not go out of our way to publicise material that sets out the weaknesses. However, we do not hide them either. We regularly run stakeholder workshops where attendees can voice their opinions.

We regard feedback – positive or negative – or concerns raised as an opportunity to learn and improve. We take concerns very seriously and review our programmes accordingly.

How are OHTA qualifications assured?

OHTA qualifications are rigorously quality assured and are scrutinised by an Awards & Qualifications Committee (AQC) with representatives of many of the major national examining boards in occupational hygiene. The examinations for each module are administered by one of a number of exam boards.

Currently the British Occupational Hygiene Society (BOHS) is the examining board for all modules at Foundation and Intermediate level, as well as the International Certificate in Occupational Hygiene (ICertOH). The ICertOH is only awarded after passing six modules, satisfactory completion of a portfolio of experience and an oral exam.

Workplace Health Without Borders (WHWB) and the Southern African Institute for Occupational Hygiene (SAIOH) are approved to run W201 exams at Foundation level. The American Industrial Hygiene Association (AIHA) is also approved to deliver the exam element of its Basic Principles elearning course, which is based on the W201 module.

All of these processes are under the oversight of the AQC who monitor on behalf of OHTA both the examinations processes and procedures for quality assurance.

Does OHTA provide professional accreditation/certification?

The OHTA scheme has been designed to provide a comprehensive framework for education and training in occupational hygiene and to retain support from the international occupational hygiene community. It has been designed to harmonise a framework for training and qualifications and to fill gaps where they exist.

The OHTA framework does not replace or compete with existing education and training courses, rather it includes and builds on them, integrating them all into a coherent framework for career development. As there are longstanding and well established schemes for professional accreditation, that are themselves accredited by IOHA, there is no need for OHTA to develop such a scheme.

Professionally accredited occupational hygienists may benefit from studying the courses that can count toward credit for continuing professional development (CPD) schemes required to maintain professional accreditation. The availability of CPD credit for OHTA modules should be checked with the appropriate exam board.