(1) In section 22(1) of the Principal Act—
(a) after "theft or" (where first occurring) insert "unexplained";
(b) omit "prescribed" (where first occurring).
(2) For section 22(2) and (3) of the Principal Act substitute —
'(2) In this section "unexplained loss" , in relation to a prescribed chemical or other prescribed substance, means any loss the cause of which cannot be explained by product density changes, spillage, calibration variances or the effects of humidity or other like things.'.