10.—(1) In any case in which—
(a)it is requisite for ensuring the maintenance of adequate control of the exposure of employees to substances hazardous to health; or
(b)it is otherwise requisite for protecting the health of employees,
the employer shall ensure that the exposure of employees to substances hazardous to health is monitored in accordance with a suitable procedure.
(2) Where a substance or process is specified in column 1 of Schedule 5, monitoring shall be carried out at least at the frequency specified in the corresponding entry in column 2 of that Schedule.
(3) The employer shall keep a suitable record of any monitoring carried out for the purpose of this regulation and that record or a suitable summary thereof shall be kept available—
(a)where the record is representative of the personal exposures of identifiable employees, for at least 40 years;
(b)in any other case, for at least 5 years.