The only consideration to extinguishers and vehicles I can think of may lay in the status of the vehicle as a 'premises' and/or any excemptions under RR(FS)O 2005 Part 1 Art.2 Interpretation: -
"premises" includes any place and, in particular, includes—
(a) any workplace;
(b) any vehicle, vessel, aircraft or hovercraft;
(c) any installation on land (including the foreshore and other land intermittently covered by water), and any other installation (whether floating, or resting on the seabed or the subsoil thereof, or resting on other land covered with water or the subsoil thereof); and
(d) any tent or movable structure;
and
Application to premises
Art. 6. —(1) This Order does not apply in relation to —
(a) domestic premises, except to the extent mentioned in article 31(10);
(b) an offshore installation within the meaning of regulation 3 of the Offshore Installation and Pipeline Works (Management and Administration) Regulations 1995[13];
(c) a ship, in respect of the normal ship-board activities of a ship's crew which are carried out solely by the crew under the direction of the master;
(d) fields, woods or other land forming part of an agricultural or forestry undertaking but which is not inside a building and is situated away from the undertaking's main buildings;
(e) an aircraft, locomotive or rolling stock, trailer or semi-trailer used as a means of transport or a vehicle for which a licence is in force under the Vehicle Excise and Registration Act 1994[14] or a vehicle exempted from duty under that Act;
(f) a mine within the meaning of section 180 of the Mines and Quarries Act 1954[15], other than any building on the surface at a mine;
(g) a borehole site to which the Borehole Sites and Operations Regulations 1995[16] apply.
(2) Subject to the preceding paragraph of this article, this Order applies in relation to any premises.
Disapplication of certain provisions
7. —(1) Articles 9(4) and (5) and 19(2) do not apply in relation to occasional work or short-term work involving work regulated as not being harmful, damaging, or dangerous to young people in a family undertaking.
(2) Articles 9(2), 12, 16, 19(3) and 22(2) do not apply in relation to the use of means of transport by land, water or air where the use of means of transport is regulated by international agreements and the European Community directives giving effect to them and in so far as the use of means of transport falls within the disapplication in article 1.2(e) of Council Directive 1999/92/EC on minimum requirements for improving the safety and health of workers potentially at risk from explosive atmospheres[17], except for any means of transport intended for use in a potentially explosive atmosphere.
(3) Articles 19 and 21 impose duties only on responsible persons who are employers.
(4) The requirements of articles 8 to 23, or of any regulations made under article 24, do not have effect to the extent that they would prevent any of the following from carrying out their duties—
(a) any member of the armed forces of the Crown or of any visiting force;
(b) any constable or any member of a police force not being a constable;
(c) any member of any emergency service.
(5) Without prejudice to paragraph (4), article 14(2)(f) does not apply to any premises constituting, or forming part of, a prison within the meaning of the Prison Act 1952[18] or constituting, or forming part of, a remand centre, detention centre or youth custody centre provided by the Secretary of State under section 43 of that Act or any part of any other premises used for keeping persons in lawful custody or detention.
(6) Where paragraph (4) or (5) applies, the safety of relevant persons must nevertheless be ensured so far as is possible.
Interesting one!