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Focus Archive

Control Banding - Threat or Benefit?

January 2005

by Paul Oldershaw, Head of the UK Health and Safety Executive's Central Specialist Division and Immediate Past President of British Occupational Hygiene Society (BOHS)

Protecting workers against possible harm from the chemicals they encounter has become narrowly focused on setting exposure limits for inhalation, meeting those standards, giving them a legal base, and measuring them to ever greater precision. It has developed into quite an industry, and has been very useful in some instances. But, is it an appropriate approach for controlling all possible chemical hazards in the workplace? Here, Paul Oldershaw gives a personal view.

If they are to be effective, exposure limits require a good evidence base and a skilled expert group to set them, a measurement system of adequate precision, the ability to both assess the measuring of the results and to act upon them, an acceptance of responsibility to update the limits with changing knowledge and a means of taking the value judgements inherent in all such systems. Not least, these capabilities also must be available to those at risk. And this list of costly, often highly limiting, needs could be extended.

Many occupational hygienists and toxicologists consider enforced limits to be a good thing, and certainly it is inconceivable that the high level of control of exposure to asbestos, silica and lead - as three examples - could have been delivered so effectively without quantification against standards. But I would argue that, for many other chemicals in many (particularly emerging) workplace situations, we need other means of ensuring effective control.

Most chemicals will never have an extensive scientific base from which to decide, quantitatively, upon the risks they bring to the workplace, since their usage and likely harm would not justify this. Year after year, perhaps two or three hundred new substances become commercially exploited in the EU, most of them probably offering no significant threat, and very few of major concern. Is their use prevented until a protective health based exposure limit is established? Certainly not! Users, perhaps on the advice of the supplier, or in keeping with common general practice in the industry, apply one of a very limited range of practical options to prevent or reduce exposure. In an ideal situation, training, personal protection, health surveillance, maintenance of plant and other standard occupational hygiene approaches will have been assessed as part of a structured health and safety management system (but that's another issue!).

Much less frequently than might be imagined, real expert help will be needed. Even measurement, with all its associated costs, will be of little practical extra benefit as a health protection tool over and above sensible controls; indeed my experience is that much environmental measurement is undertaken primarily to meet the need to show compliance with a legal limit and / or for defensive purposes against possible future claims of ill-health.

In many countries there are, indeed, national lists of exposure limits, but little or none of the resources necessary to give them practical effect. Occupational hygiene skills are rare, the infrastructure needed for measurement largely absent and, where it is present, not widely available at acceptable cost to those at risk. The capability is largely held within the big, sometimes multinational, enterprises and is not strong within the regulatory authorities who may have many other demands on their limited resources. Should expert advice be sought, it may well be prohibitively expensive if available at all.

In these situations other complementary means of practical health protection are clearly needed to ensure that a sensible, cost effective approach to control is taken by the user at the earliest opportunity, and that measurement and highly skilled risk assessment is directed only to those areas where it is justified, which will be a minority of cases.

One way of doing this is through Control Banding, which helps users to control key processes with the minimum of outside intervention. By taking the chemical hazard data (agreed for many thousands of substances across the European Community), combining it with their knowledge of their process and a simple indication of the likelihood of the substance becoming airborne (e.g. dustiness or volatility), users can feed this into a simple system, out of which come practical control suggestions. This guidance is put together by occupational hygienists with a good knowledge of the relevant industries and builds upon practical experience and accepted good practice. The system can be set up to direct the user to seek expert assistance, as it would do, for example, with carcinogens. This approach is known as e-COSHH Essentials within the UK where it was developed by the Health and Safety Executive, and has been extensively trialled, nationally and internationally, through a joint initiative by ILO, WHO and IPCS. Indeed the concept is being developed in many guises.

So is there universal acclamation? Not exactly - its reception is mixed. Some criticise it as though it seeks to be an expert system carrying out a risk analysis. It doesn't, however, aim to do this, as it defaults to directing the user to expert advice. Some criticise it as not being how toxicology should be carried out. I would argue that it doesn't look to do this, but actually builds upon much of the same information used for limit setting and chemical classification. Others say "interesting idea, but couldn't work here", whilst yet others see Control Banding as cutting across legal duties linked to compliance with exposure limits.

If this position, frozen by tradition or law, prevails then we will never be effective in addressing the risks to many workers, in most of the world, who have no access to the skills and resources to turn exposure limits into effective control.

If you want to explore the Control Banding approach to the control of chemical exposure, the UK system is freely available at: and the international version, developed through ILO/WHO/IPCS, at:

Paul Oldershaw joined the UK Health and Safety Executive (HSE) in 1974 as an inspector specialising in occupational hygiene problems, and has since held many positions relating to health. He now heads HSE's Central Specialist Division. Paul has worked for many years in collaboration with the World Health Organisation (WHO), the International Labour Office (ILO) and within the European Community. He is a Fellow of BOHS's Faculty of Occupational Hygiene, and has held the post of President of British Occupational Hygiene Society (BOHS) twice, in 1992 and 2003, the only person to have done so in the Society's 50 year history. He is also a Past President of the International Occupational Hygiene Association (IOHA) and heads its Co-operation in Occupational Hygiene Programme. The views expressed in this article are his own and do not necessarily reflect those of the HSE, BOHS or IOHA.