The gas supply companies, in the widest sense of their activities (production, transport, distribution), have a long tradition in ensuring that networks and facilities are operated according to well-defined procedures. These procedures are the centrepiece of quality management systems. They are based on the general criteria of the series ISO 9000 and are currently being developed gas-specifically as EQAS (European Quality Assurance System) in CEN/TC 234 in order to adhere more efficiently to the procedures peculiar to the gas activities. Companies are more and more inclined to take into account environmental aspects since the series ISO 14000 resulting in EMAS (Environment Management System). As both the series and the system possess a similar structure, the measures to be taken are directly linked to the technical operations and therefore cannot be dissociated from them. Environmental issues are expected to feature increasingly in CEN standardisation as the European Commission and its affiliated Member States press ahead with an array of proposals for potential directives. These directives are aimed at boosting the reduction of energy consumption, reducing emissions to air/water and, more generally, at forcing industry to consider any process which may have adverse impacts on the environment.