NEBOSH Chemical and Biological Hazards 6

Question 1

What does the GHS exclamation mark pictogram indicate?

Accepted Answer

Less severe health hazards including skin and eye irritation, respiratory tract irritation, narcotic effects, and skin sensitisation

Answer

The exclamation mark pictogram (GHS07) indicates less severe health hazards including: skin irritation, eye irritation, respiratory tract irritation, narcotic effects, skin sensitisation, and acute toxicity (harmful). It covers hazards that are real but less severe than those indicated by the skull and crossbones or health hazard (silhouette) pictograms.

Question 2

A worker develops contact dermatitis after regularly handling a particular cleaning chemical. What does this suggest about the failure of COSHH controls?

Accepted Answer

The COSHH assessment may have failed to adequately identify the skin hazard, control measures such as gloves may be inadequate, or health surveillance may not have detected early signs

Answer

Contact dermatitis indicates a failure in the COSHH control chain: the assessment may not have identified the skin route risk, substitution with a less hazardous product may not have been considered, glove selection may be wrong (incorrect material, wrong size, or insufficient change frequency), training may be inadequate, or health surveillance (regular skin inspections) may have failed to detect early signs for intervention.

Question 3

What is the 'Sk' notation in EH40 (Table 1 of Workplace Exposure Limits) and why is it important?

Accepted Answer

Sk indicates the substance can be absorbed through intact skin, contributing significantly to overall body burden, meaning air monitoring alone may underestimate total exposure

Answer

The 'Sk' notation in EH40 warns that the substance can be significantly absorbed through intact skin. This means that even if airborne concentrations are below the WEL, significant exposure can occur via skin contact. Employers must consider skin exposure in their COSHH assessment, provide appropriate gloves/clothing, and may need biological monitoring to assess total body burden.

Question 4

What measures should be taken when a COSHH assessment identifies a substance as a respiratory sensitiser?

Accepted Answer

Eliminate or substitute where possible, enclose the process, provide effective LEV, establish health surveillance for early detection of sensitisation, and ensure any sensitised individuals are removed from further exposure

Answer

Respiratory sensitisers require stringent control because once sensitisation occurs, even minute exposures can trigger severe asthmatic reactions. Controls must include: elimination/substitution priority, total enclosure or effective LEV, appropriate RPE where engineering controls are insufficient, health surveillance (lung function testing) for early detection, and immediate removal from exposure of any worker showing signs of sensitisation.

Question 5

What is the difference between a hazard and a risk in the context of COSHH?

Accepted Answer

A hazard is the intrinsic potential of a substance to cause harm; risk is the likelihood that harm will actually occur given the circumstances of use, including the level and duration of exposure and the effectiveness of controls

Answer

In COSHH terms, hazard is the inherent property of a substance to cause harm (e.g., a solvent is toxic — this is fixed by its chemistry). Risk is the likelihood that harm will occur under the actual conditions of use, considering: the quantity used, how it is used, the duration and frequency of exposure, who is exposed, and the effectiveness of control measures in place.

NEBOSH IGC Practice Test

NEBOSH IGC Practice Test

NEBOSH Chemical and Biological Hazards 6