I inspect and test filling stations. Push on at the moment to accredit competence in this area in the UK. On investigation, costs for such accreditation are excessive.
Are there restrictions imposed elsewhere?

Lyle,

This is not an area I've ever worked in, although I'm aware of some of the general requirements such as the ban on TN-C-S (PME) for filling stations.

I'm aware that rules in Northern Ireland are often slightly different to those in England? Is this something which might be applied differently in your part of the UK?

Lyle,
Over here in NZ, this field is a very restricted one, you pretty much have to have started out as a Trainee Electrician/Instrument Tech in the Petro-Chemical Industry, to even think about working around electrical gear in this field, let alone inspect it.
There's a whole heap of courses(read otential money-making scheme)around to provide knowledge and skills for those that inspect and certify these Hazardous Areas(as they are called over here) and man are they expensive

Paul,
No, the rules are the same.The guidance is issued by the Association of Petroleuum and Explosives Administration and the Institute of Petroleum.
I had to undertake specialist training for hazardous areas. I have no problem with this. What annoys me is the sudden plethora of accreditation bodies trying to squeeze a few more quid out of us!