Introduction to Health and Safety at Work

Principles of control
85
➤
exposure to ionising and non-ionising radiation 
including ultraviolet in the sun’s rays, causing burns, 
sickness and skin cancer
➤
infections ranging from minor sickness to life-
threatening conditions, caused by inhaling or being 
contaminated by microbiological organisms
➤
stress causing mental and physical disorders.
Some illnesses or conditions, such as asthma and back 
pain, have both occupational and non-occupational 
causes and it may be diffi cult to establish a defi nite 
causal link with a person’s work activity or their expos-
ure to particular agents or substances. But, if there is 
evidence that shows the illness or condition is preva-
lent among the type of workers to which the person 
belongs or among workers exposed to similar agents or 
substances, it is likely that their work and exposure has 
contributed in some way.
6.4.2
Control hierarchy for exposure to 
substances hazardous to health
The following shows how the general principles and hier-
archy can be applied to substances hazardous to health, 
which come under the COSHH Regulations:
➤
change the process or task so that there is no need 
for the hazardous substance
➤
replace the substance with a safer material
➤
use the substance in a safer form, for example, in 
liquid or pellets to prevent dust from powders. The 
HSE has produced a useful booklet on 7 
steps to 
successful substitution of hazardous substances
HSG 110, HSE Books, which should be consulted
➤
totally enclose the process
➤
partially enclose the process and use local exhaust 
ventilation to extract the harmful substance
➤
provide high quality general ventilation, if individual 
exposures do not breach the exposure limits
➤
use safe systems of work and procedures to min-
imize exposures, spillage or leaks
➤
reduce the number of people exposed or the dur-
ation of their exposure.
If none of the above control measures prove to be 
adequate on their own, PPE should be provided. This 
is a last resort and is only permitted by the COSHH 
Regulations in conjunction with other means of control 
if they prove inadequate. Special control requirements 
are needed for carcinogens, which are set out in the 
Carcinogen Approved Code of Practice.