# The Misuse of Drugs (Safe Custody) Regulations 1973, Paragraph 3


(1) Each wall shall be securely attached to the floor, ceiling and adjacent walls and shall be constructed of—
(a) bricks laid in cement mortar to at least 229 millimetres (9 inches) thickness or, if the joints are reinforced with metal reinforcing ties, to at least 115 millimetres (4 ½ inches) thickness; or
(b) concrete (being solid concrete, reinforced concrete or dense concrete blocks laid in cement mortar) of at least 152 millimetres (6 inches) thickness, the joints being reinforced with metal reinforcing ties where concrete blocks are used; or
(c) steel mesh fixed externally by welding upon angle-iron frames of at least 50 millimetres (2 inches) by 50 millimetres (2 inches) section and 6 millimetres (¼ inch) thickness, having vertical members not more than 610 millimetres (2 feet) apart and horizontal members not more than 1220 millimetres (4 feet) apart; or
(d) sheet steel fixed externally by welding, or bolting with steel bolts of not less than 12 millimetres (½ inch) diameter and at intervals of not more than 305 millimetres (1 foot), upon either angle-iron frames as specified in (c) above or timber frames of at least 50 millimetres (2 inches) by 100 millimetres (4 inches) section, having vertical and horizontal members spaced as specified in (c) above.
(2) If a party wall or, in the case of a room of which the floor level is less than 2440 millimetres (8 feet) above the external ground level, an external wall is used to form one of the walls of the room, that wall shall be reinforced internally by means of an additional wall which is constructed in accordance with the requirements of sub-paragraph (1) above.
(3) The floor shall be—
(a) constructed of solid concrete or reinforced concrete; or
(b) covered internally with sheet steel or steel mesh, welded at all joints; or
(c) otherwise so constructed that it cannot be readily penetrated from below.
(4) The ceiling shall be constructed of—
(a) solid concrete or reinforced concrete as specified in sub-paragraph (1)(b) above; or
(b) steel mesh fixed externally by welding upon angle-iron frames as specified in sub-paragraph (1)(c) above, the members of which shall not be more than 610 millimetres (2 feet) apart in one direction or more than 1220 millimetres (4 feet) apart in the other; or
(c) sheet steel fixed externally by welding upon angle-iron frames as specified in sub-paragraph (1)(c) above, the members being spaced as specified in (b) above.
(5) Each door or, in the case of a stable-type door, each half-door shall be constructed of—
(a) steel mesh fixed externally by welding upon angle-iron frames as specified in sub-paragraph (1)(c) above; or
(b) sheet steel fixed externally by welding upon angle-iron frames as specified in sub-paragraph (1)(c) above, the members being spaced as specified therein; or
(c) sheet steel fixed externally upon a hardwood frame of at least 50 millimetres (2 inches) by 75 millimetres (3 inches) to stiles, rails and braces or muntins by means of coach bolts at intervals of not more than 305 millimetres (1 foot) (the nuts whereof being on the inside of the door) and with non-withdrawable screws between the bolts at intervals not exceeding 100 millimetres (4 inches), the members of the frame being spaced as specified in sub-paragraph (1)(c) above; or
(d) sheet steel fixed externally upon a solid timber core of at least 50 millimetres (2 inches) thickness.
(6) Each door or, in the case of a stable-type door, each half-door shall be fitted with an effective lock, being a single-sided dead lock having resistance to manipulation and forcing sufficient to comply with the requirements of the Standard of 1963.
(7) If the room is fitted with a two-leaf door, the second opening leaf shall be secured top and bottom by means of—
(a) an espagnolette bolt, operated only from within the room, with vertical fastening rods of mild steel of at least 16 millimetres (⅝ inch) by 16 millimetres (⅝ inch) section or 16 millimetres (⅝ inch) diameter; or
(b) at least two internal tower bolts of mild steel of at least 16 of millimetres (⅝ inch) diameter, designed to swivel into a secure holding recess when in the thrown position,
and in either case the bolt shall have a total throw at least 25 millimetres (1 inch) greater than the clearance between the door and the floor or lintel, as the case may be, the lower shooting hole being kept at all times free from obstruction.
(8) The closing frame of each doorway shall be constructed of—
(a) an angle-iron frame as specified in sub-paragraph (1)(c) above; or
(b) hardwood of at least 50 millimetres (2 inches) by 100 millimetres (4 inches) section, covered by sheet steel bolted through the timber at intervals not exceeding 457 millimetres (18 inches) by means of coach bolts (the nuts whereof not being accessible from outside the room); or
(c) pressed steel not lighter than 10 gauge welded at all joints.
(9) Each section of the closing frame of each doorway shall be fixed to the adjoining wall at intervals not exceeding 457 millimetres (18 inches) by means of—
(a) where the wall is constructed of bricks, bent and tanged straps of wrought-iron, screwed or bolted to the frame and built into the brickwork;
(b) where the wall is constructed of concrete, rag-bolts; or
(c) where the wall is constructed of steel mesh or sheet steel, steel bolts or dowels of at least 12 millimetres (½ inch) diameter or welding to the framework or cladding of the room.
(10) Each glass window shall either be constructed of glass blocks not larger than 190 millimetres (7 ½ inches) by 190 millimetres (7 ½ inches) and of at least 80 millimetres (3 ½ inches) thickness, set in a reinforced concrete frame having a reinforcing bar between every block, or be guarded by a grille consisting of—
(a) panels of steel mesh fixed on angle-iron frames as specified in sub-paragraph (1)(c) above and fixed—
(i) where the surrounding wall or ceiling is constructed of sheet steel on angle-iron frames, by welding to the sheet steel or framework at intervals not exceeding 305 millimetres (1 foot); or
(ii) where the surrounding wall is constructed of sheet steel on timber frames, by means of steel bolts of at least 12 millimetres (½ inch) diameter, bolted through the timber at intervals not exceeding 457 millimetres (18 inches); or
(iii) where the surrounding wall is constructed of bricks, by means of bent and tanged straps of wrought-iron screwed or bolted to the frame and built into the brickwork at intervals not exceeding 457 millimetres (18 inches); or
(iv) where the surrounding wall or ceiling is constructed of concrete, by means of rag-bolts at intervals not exceeding 457 millimetres (18 inches); or
(b) vertical bars of solid mild steel of at least 25 millimetres (1 inch) by 25 millimetres (1 inch) square section, having one of their diagonal axes in a plane parallel to that of the window aperture, spaced not more than 127 millimetres (5 inches) apart centre to centre with the outer bars not more than 75 millimetres (3 inches) from the reveals of the window, and running through and welded to flat mild steel horizontal guard-bars which—
(i) are of at least 62 millimetres (2 ½ inches) width and 9 millimetres (⅜ inch) thickness;
(ii) are spaced not more than 762 millimetres (2 ½ feet) apart, the upper and lower guard-bars being at a distance not exceeding 100 millimetres (4 inches) from the ends of the vertical bars and not exceeding 75 millimetres (3 inches) from the head and sill of the window;
(iii) are welded at each end to steel brackets of at least 152 millimetres (6 inches) length, 62 millimetres (2 ½ inches) width and 12 millimetres (½ inch) thickness fixed to the surrounding wall or ceiling, as the case may be, in the manner required by (a) above at a distance of at least 152 millimetres (6 inches) from the reveals of the window;
(iv) if more than 1830 millimetres (6 feet) in length, have the uppermost and lowermost of them fixed to the head and sill of the window at intervals not exceeding 1830 millimetres (6 feet), by means of angle-iron fixings of at least 50 to millimetres (2 inches) by 50 millimetres (2 inches) section and 6 millimetres (¼ inch) thickness welded to the guard-bars and fixed to the surrounding wall or ceiling, as the case may be, in the manner required by (a) above.
(11) Each service-hatch shall be guarded by a grille consisting of—
(i) panels of steel mesh or sheet steel on angle-iron frames as specified in sub-paragraph (1)(c) above; or
(ii) vertical bars of solid mild steel as specified in sub-paragraph (10)(b)(i) and (ii) above,
and the grille shall be secured at all times when the hatch is not in use in such a way as to be secure against removal from outside the room.
(12) Each aperture other than a window or service-hatch shall be guarded by a grille which satisfies the requirements of sub-paragraph (10)(a) or (b) above.
(13) Each shelf in a room shall be so situated as to prevent drugs placed upon it from being extracted from outside through any aperture.
(14) Nothing shall be displayed outside a room to indicate that drugs are kept in the room.

---
Source: https://www.legislation.gov.uk/uksi/1973/798/schedule/2/paragraph/3 (the official version)
Page: https://openlegislation.uk/misuse-of-drugs-safe-custody-regulations-1973/schedule-2/paragraph-3
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.