chrisch
Contributor
The important word is should...
What you're assuming is that filling stations are infallible. Even the most diligent of operators can have issues.
Personally I don't consider £100 per year too much of a cost in the great scheme of the annual costs of diving
My opinion is that I disagree with the principle, others like you have a different view
For sure it is possible that the gas might be contaminated - you are right they are not infallible. However the cost/benefit is the (for me) the main issue. You might not consider £100 too much but many people do. I can buy a tank for not much more than that so in reality I would never bother testing a tank, just buy a new one. To be fair we are nearly at than point now with a hydrostatic test with O2.
Quite apart from the stupid waste (and environmental cost) this represents a more simple solution which is to have a compressor. Your 18 tanks at £100 each will buy a compressor and it would pay for itself in a year. I have 8 tanks that need testing so would look at that option too. (A 300bar tank and filling whip is another cheap alternative)
An annual test is more of the "just in case" nonsense that gets labelled "nanny state" or "health and safety" and generally is driven by profit not concern for anyone's safety or a tin foil hat view of the role of government. The BSAC have - quite rightly - represented the views of the majority of UK divers and have put forward the view this is a solution looking for a problem. That is the job of the UK governing body and they have done their job well.
Ultimately the decision whether to fill or not and what testing regime is required should be up to the person filling. That person should have the final say.