Control of exposure and control measures

The Regulations set out a hierarchy of control, which must be followed.

(a) Prevent exposure to hazardous substances where reasonably practicable, e.g.

 (i)     change the procedure so that hazardous substances are not required, or not produced (e.g. use colophony-free solder to avoid the generation of colophony fumes, which may cause asthma, from traditional resin-cored solder).

(ii)     use a safer alternative substance (e.g. use Decon instead of chromic acid for cleaning glassware, where possible).

(iii)     use a safer form of the substance (e.g. use premixed acrylamide solutions instead of acrylamide powders, to avoid exposure to acrylamide dust).

(b) If exposure cannot be prevented, it must be adequately controlled.

(i)     The eight principles of good practice set out in Appendix 2 must be applied.

(ii)     If there is a WEL for the substance used, then it must not be exceeded.

 (iii)     If the substance causes cancer, heritable genetic damage or asthma, then exposure must be reduced to as low a level as reasonably practicable.

(c) The principles of good practice define an order of priority for the choice of control measures where exposure cannot be prevented by the methods described in (a) above.

(i)     Totally enclose the process (e.g. by using a glove box or Class 3 microbiological safety cabinet).

(ii)     Change the system of work so as to minimise the number of people exposed, to limit their exposure time (e.g. by controlling access to areas of particular hazard), and to minimise the amount of hazardous substance used or produced.

(iii)     Use partial enclosure with LEV (e.g. a fume cupboard or Class 1 or 2 microbiological safety cabinet); use LEV (e.g. dust extraction equipment on woodworking machinery, or tip extraction on soldering irons); ensure there is good general ventilation.

(iv)     Provide safe handling, storage, transport and disposal of hazardous substances (e.g. use only the minimum quantity and use double containers where danger would arise from spillage in storage or transport).

(v)     Provide adequate hygiene measures (e.g. provide facilities for laundering lab coats and other protective clothing; enforce the prohibition on eating or drinking in laboratories).

(vi)     Use personal protective equipment (PPE) only where adequate control cannot be achieved by other measures, and then use it only in addition to those measures (e.g. you must not provide dust respirators as an alternative to providing LEV).

Note that where tight-fitting respiratory protective equipment (RPE) is provided as a control measure, then face fit testing will be required (see Appendix 4, which contains more information on PPE).