2.1 Factors to consider when assessing CoSHH risks

Question 1

In order to achieve the above it is necessary to consider a range of factors in each
CoSHH risk assessment. 12

Answer 1

1. The hazardous properties of a substance
2. Exposure
   D. duration
   A. activities
   F. frequency
   T. thresholds
   T. type
   L. level
   N. no. of people
3. Route of entry
4. Particle size of solids
5. Volatility of liquids
6. Concentration
7. Solubility
8. The nature of the task
9. Mixtures of chemicals
10. Effectiveness of existing control measures
11. Results from health surveillance and monitoring
12. Individual susceptibilities

Question 2

LD 50 :

Answer 2

the ingested dose which kills 50% of the test population, measured in milligrams/micrograms per kilogram of body weight.

Question 3

LC 50 :

Answer 3

airborne concentration of a toxic substance lethal to 50% of the test population, measured in millilitres per kilogram of body weight.

Question 4

The nature of the task will also affect exposure to hazardous substances.
Employees may be exposed: 5

Answer 4

 Directly i.e. by doing the task

 Indirectly i.e. by passive exposure to the hazardous substance in the work area

 Undertaking cleaning or maintenance tasks

 By contact with contaminated work areas, clothing etc.

 Accidental release of a hazardous substance.

Question 5

Mixtures of chemicals 4

Answer 5

Additive effects: The combined effect equals the sum of the effects of each chemical alone, i.e. 1 + 1 = 2

Synergistic effects: The combined effect is larger than the sum of the effects of each chemical alone, i.e. 1 + 1 = 40.

Antagonistic effects: The combined effect is less than the sum of the effects of each chemical alone, i.e. 1 + 1 = 0.

Potentiating effects: A chemical that normally has no effect will increase the effect that another chemical would have alone, i.e. 0 + 1 = 3

Question 6

Individual susceptibilities

Employers are required to protect particular groups of employees who may be at an
increased risk, for example: 7

Answer 6

 Inexperienced trainees and young people aged under 18

 Pregnant workers

 Disabled workers

 Any employees known to be susceptible to certain illnesses such as dermatitis

 Any employee suffering atopic (allergic) asthma due to pollen, or eczema due to dust mites etc. may consequently be at more risk of sensitisation to a work exposure to a sensitising agent

 Any employee known to be previously sensitised to a work based skin or asthma sensitising agent

 Any employee with pre-existing medical conditions, which could be made worse by exposure to chemicals.