Under Section 7 of the Health and Safety at Work etc Act 1974 employees have a duty to take reasonable care for the health and safety of themselves and others who may be affected by their acts or omissions whilst at work. This extends to co-operating to enable the employer to fulfill its legal duty:

Section 7 of the Health and Safety at Work Act 1974:

General duties of employees at work.

It shall be the duty of every employee while at work—

(a)to take reasonable care for the health and safety of himself and of other persons who may be affected by his acts or omissions at work; and

(b)as regards any duty or requirement imposed on his employer or any other person by or under any of the relevant statutory provisions, to co-operate with him so far as is necessary to enable that duty or requirement to be performed or complied with.