The Union was founded as a direct result of the Piper Alpha disaster, deriving its origins from an ad-hoc committee of workers formed in the immediate aftermath that grew into an independent trade union in 1992. Its membership of some 5,000 is drawn from people employed in the UK offshore oil industry irrespective of whether they are directly employed by an oil field operator or indirectly by a contractor. Whereas the Offshore Industry Liaison Committee or the OILC is the only union specifcally directed at offshore workers it is not affiliated to the Trades Union Congress as the monolithic Amicus already regards the offshore industry as its own territory.

As a result of this history the Union's primary concern is not pay and conditions but rather one of ensuring the safety of its members who are engaged in an industry where risks of death or serious injury are higher than normal.