This British Standard specifies performance requirements and test
methods for a thief resistant mechanically operated single-point lock
assembly (including locking plates, fixing screws, fitting instructions
and cylinders and protective furniture where appropriate) that:
a) incorporates a lock conforming to BS EN 12209:2003 field of door
application grades A, B, C, D, E, F or J that, under normal
conditions, can be unlocked from the inside without the use of a
key, thereby allowing keyless egress;
b) can be changed to a secure (no egress) mode by a secondary
positive locking action;
c) is used in doors, window doors and entrance doors in buildings.
This standard covers only those thief resistant lock assemblies that are
intended for use in dwellings where there is an alternative escape route.
It does not cover thief resistant lock assemblies that provide keyless
egress at all times since these are covered by BS 8621, nor does it cover
thief resistant lock assemblies that require the use of a removable key
for egress since these are covered by BS 3621.
NOTE It is possible that lock assemblies conforming to this standard are
not suitable for use on doors constructed from certain types of material,
e.g. plastic or aluminium. The marking on the packaging of the lock
assembly will provide this information in accordance with Clause 9.