management overview

Managing such a wide range of substances requires a simple and logical approach to ensure that all aspects are covered. This approach is outlined below and covers:

1. Risk assessment
2. Prevention or control of exposure
3. Managing control measures
4. Monitoring exposure
5. Health surveillance
6. Information and training

Where the substance is a mixture, expert assistance may be needed to establish its characteristics, otherwise the worst case should be considered, i.e. the mixture should be assumed to have the worst characteristics of its constituents.

The risk assessment needs to take account not only of the substance but also its form: the method used for a liquid will differ if the same substance is in the form of a mist or vapour. Using the wrong method could result in misleading conclusions and permit potentially dangerous exposure levels. There are notes on risk assessment techniques for a range of substance types later in this chapter.

The risk assessment should also define the method(s) of control with specifications, where appropriate.

Prevention or control of exposure

There is a common approach to preventing or otherwise controlling exposure. It is known as the hierarchy of control. This means that the following measures are taken in order of priority to control exposure, for instance, first eliminating the use of the substance. This approach can be used for many kinds of hazard.

The hierarchy of prevention or control is:

• eliminating the use of the substance;
• substituting the substance with a less hazardous one;
• reducing the risk by separating the operators from the substance (by process automation, for example);
• reducing the risk by introducing engineering controls (like local exhaust ventilation (LEV)); and
• reducing the risk by the use of appropriate personal protective equipment (PPE).

NOTE – the use of personal protective equipment (PPE) is normally considered to be ‘a last resort’ and definitely not suitable where the substance is a carcinogen or a biological agent. In this case, other measures must be taken higher up the hierarchy.

The control measures specified in the risk assessment should be capable of controlling exposure to employees well within the workplace exposure limit (WEL) as defined in the HSE publication EH/40. This should be the case under all reasonably foreseeable ‘worst conditions’ during normal operations. The procedures and equipment to cover emergency circumstances will also need to be specified, if applicable, as described in Planning for emergencies.

Managing control measures

There are three main ways of controlling hazardous substances in use:

• Separate the operators from the process.
• Efficiently remove any hazardous spray, mist, vapour or smoke as close to the point of generation as possible.
• Protect the operator(s) with appropriate personal protective equipment.

All of these measures use equipment that will generally become less effective with age. Seals on separating barriers can wear and leak; extraction efficiencies on LEV installations deteriorate as filters become clogged and duct interior walls attract deposits; and personal protective equipment can get dirty and mis-shapen with use.

You need to monitor the effectiveness of all COSHH control measures regularly by:

• carrying out visual checks at appropriate intervals;
• ensuring different items of personal protective equipment are compatible when more than one is used by a single person;
• ensuring that employees use the controls properly; and
• promptly completing any outstanding actions.

Employees also have responsibilities to ensure they use the COSHH control measures provided in accordance with their training and manufacturers’ instructions, and maintain high standards of personal hygiene, especially when eating, drinking or smoking.

Certain types of controls, e.g. local exhaust ventilation installations, also need to be tested annually by a competent person (usually an insurance engineer or similar) to check that their performance remains within prescribed limits. You will receive a copy of the examination report, which will include any remedial actions necessary to restore their performance.

Each action normally has a given priority. If an action has the highest priority, the competent tester may need to send a copy of the report to the enforcing authority. If this occurs, you should ask the test engineer if you need to advise the enforcing authority of the corrective action(s) you have taken.

Monitoring exposure

If the risk assessment establishes that employees could be exposed to concentrations approaching the workplace exposure limit (WEL), you should ensure that employees’ exposure levels are properly monitored.

Records should be maintained of all such monitoring results and kept for at least 40 years if they relate to personal exposure of identified employees or at least five years otherwise.