The traditional practice of industrial hygiene follows the sequence of anticipation, recognition, evaluation, and control.Anticipationandrecognitioncomprise the basic characterization of a hazard and employee exposure. Evaluationconsists of an exposure assessment where measurements are taken. If the measurements find unacceptable exposure thencontrolssuch as local exhaust ventilation are used.

What if we alter this sequence by placing evaluation last or eliminate the evaluation step altogether — will the practice of IH no longer work?

This question is an important argument for “control banding” strategies that are growing in use worldwide.

Table 1

What is control banding?

NIOSH’s homepage on this topic — http://www.cdc.gov/ niosh/topics/ctrlbanding/ — breaks down the components of control banding:

1 — A single control technology (such as general ventilation or containment)

2 — Applies to one range or “band” of exposures to a dust or vapor (such as 1 to 10 mg/m3)

3 — Falling within a given hazard group (such as skin and eye irritants or severely irritating and corrosive).

NIOSH provides an example of control banding in Table 1.

Under the control banding strategy the chemical groups posing the greatest harm are given the greatest degree of control. Evaluation is not included in the strategy.

Figure 1

Goodbye expert advice?

With the exception of special chemical groups, such as reproductive hazards, control banding strategies lessen or eliminate the need for expert advice. This is another contentious point with control banding — will the strategy weaken or enhance the IH profession?

The United Kingdom requires employers to conduct risk assessments for chemical hazards, and the UK provides a free online control banding tool called COSHH Essentials (http://www.coshh-essentials.org.uk/) to help meet the requirement.

COSHH Essentials allow a non-IH professional, such as a plant supervisor, to perform the basic characterization of a chemical hazard and employee exposure using data such as task information, hazard classification, volatility or dustiness of the chemical, and amount of chemical used in the task. Figure 1 is an example of how the control banding tool helps place a chemical assessment into a hazard group or band.

As with the NIOSH example, COSHH Essentials identifies “special cases” (special chemical groups) that require expert advice. If the task, however, is not a special case then the tool will recommend an engineering control such as local exhaust ventilation or containment. COSHH Essentials provides users with design and operating guidance for recommended engineering controls.

Does control banding work?

Ninety-four percent of COSHH Essentials users (500 people surveyed by the UK’s Health & Safety Executive) would recommend it to other businesses. A validation study for COSHH Essentials finds:

  • In 52 percent of the cases studied the tool was equivalent to an occupational exposure limit (OEL);

  • Forty-six percent of the cases were more stringent than the OEL; and,

  • In two percent of the cases the tool was less stringent than the OEL.

    Global harmonization

    Control banding works best where everyone agrees on the hazards of a chemical. The United Nations has developed a Globally Harmonized System (GHS) for chemical hazard classification and labeling. GHS is scheduled to be implemented worldwide by 2008. GHS should help promote control banding strategies around the world.

    Most countries in the European Union (EU) are more compliant with GHS at present than the United States — particularly with use of standardized “risk phrases” for many chemicals.

    EU countries such as Belgium, France, Germany, Netherlands and Norway are, therefore, more experienced using control banding strategies.

    The 3rd International Control Banding Workshop is scheduled to be held in South Africa later this year. Control banding strategies may have great appeal in developing countries that lack sufficient IH expertise. The International Labour Organization (ILO), World Health Organization (WHO), and International Occupational Hygiene Association (IOHA) are some of the international organizations that are promoting control banding strategies.

    Your actions

    Control banding strategies have worldwide appeal. They are gaining in popularity and acceptance. The strategy may work for chemicals lacking an OEL. And control banding is also expanding into other hazards, ergonomics being one example.

    Not everyone who examines control banding strategies likes what they see and hear. Some see it as an affront to the IH profession. Others see it as a practical solution for getting employers to use exposure control methods such as exhaust ventilation more often.

    Legal hurdles in the U.S. are a major issue. For example, can compliance with chemical exposures be demonstrated without exposure measurements?

    Control banding strategies, though, are here to stay. You should follow with an open mind how these strategies are being used (NIOSH’s homepage on the topic is a good place to start) and apply them at your work site as appropriate.