The international qualifications scheme allows you to study occupational hygiene at the level that suits you using a modular design. This gives you the flexibility to build on your existing qualifications and to fit in more easily with your job demands.  You can start from the basic principles level and progress through to Intermediate level, through which you can work towards the International Certificate. 


Examining boards from across the world have come together to agree a common framework of qualifications.  OHTA provides training materials to Approved Training Providers to help you demonstrate your knowledge. Please note that International qualifications cover the core science and practice of occupational hygiene; they do not cover the details of local legislation or local custom and practice.

The international scheme requires the completion of 6 modules, . 

The 4 core modules are:

W501: Measurement of Hazardous Substances

W503: Noise Measurement and its Effects

W505: Control of Hazardous Substances

W507: Health Effects of Hazardous Substances 

The 3 optional modules are:

W502: Thermal Environment

W504: Asbestos and Other Fibres

W506: Ergonomics Essentials

During the courses you are required to demonstrate that you can carry out basic practical assessments under the supervision of course tutors. To meet the aims of the intermediate level courses and for you to reach the required level of technical and practical skill you will continue to develop those skills through practical experience in the work environment. You will need to collect evidence which demonstrates you have applied your knowledge in practical situations. This will be documented in your Personal Learning Portfolio.


On completion of each module, you will receive an Award of Successful Course Completion for that module. Once you have completed 6 modules, you can progress to the award by completing a Personal Learning Portfolio. 

Once you have completed your portfolio you can apply for an interview for the award of the International Certificate.