I'm trying to find a definitive description of the competencies that an individual would need to work as an Occupational Health Advisor and also those for a Senior Occupational Health Advisor.

To be honest I'm struggling and after spending about an hour on the web trawling through various sites, I'm not much clearer!

I might be little naiive here, but if you were thinking about a H&S Practitioner, you might (arguably) say that the NEBOSH Certificate was a starting point for a basic role (I know this may be seen as controversial, but I use it simply as an example, I'm aware that competency does not begin and end with a bit of paper, but I hope you see my point)! Also, a more senior H&S Practitioner might be seen as CMIOSH; but is there any similar qualification based judgement that might be made to distinguish between grades of OH Advisors?

Thanks in advance.

There is also the British Occupational Hygiene Society (BOHS) which covers Health issues such as exposure to chemicals, dusts etc...

You have picked up the main accrediations to look at, there may be some more depending on what sector you are in and what their main duties will be?

There are several aspects to your desire to find what you call a "definitive description of the competencies that an individual would need to work as an Occupational Health Advisor and also those for a Senior Occupational Health Advisor."

A 'definitive' description can only be determined by the executive board of your organisation, who are legally and otherwise in the best position to co-ordinate roles for whose performance they are responsible.

Useful guidance about relevant competencies is available from the relevaant professional society, the Association of Occupational Health Nurse Practitioners, www.aohnp.co.uk, some of whose members are IOSH members.

Yet as the nursing tradition is a medical one, and in the UK has been largely conditioned by the NHS; so, it's quite different to that of the IOSH.