insert
"medical gas" means a substance used for medical purposes and prescribed as a medical gas.
"medical gasfitting work—"
(a) means the construction, installation, replacement, repair, alteration and maintenance of a medical gas system; and
(b) if incidental to the work in paragraph (a)—includes design work and testing.
"medical gas system" means a reticulated system of pipes, hoses or lines that carries or controls the supply or removal of medical gas—
(a) including related fixtures and fittings and any other thing prescribed by regulation; but
(b) not including anything connected to, and extending or situated beyond, a wall outlet or non-interchangeable screw thread fitting.
"medical gas technician work" means the commissioning, testing, verification
or certification of a medical gas system.
Part 11 Gas Safety Regulation 2001