Adding to the risk management toolbox

Experts consider the potential for control banding methods

By Deidre Bello, associate editor

  • Experts say more variations of the control banding model will develop as the number of chemicals globally in use continues to grow and new occupational hazards emerge.
  • Some in the research community are discussing expanding application of control banding beyond chemicals.
  • Although control banding can help enhance traditional occupational exposure level approaches to risk assessment, the method has some limitations.
  • NIOSH and a number of professional associations are continuing to develop control banding guidance for small and medium-sized organizations.

With more than 880,000 hazardous chemicals currently in use in the United States, training workers to recognize and protect against health risks can be a challenge for small and medium-sized organizations. The charge is even more complicated during tough economic times, when companies may not have an industrial hygienist on staff.

In recent years, however, safety and health practitioners have been hearing more about the potential of a qualitative analysis tool intended to help workers improve the way they identify substances and other occupational hazards. That tool – control banding – is a method for applying a single control technology to one range or band of exposures to a chemical that falls within a given hazard group. Industrial hygiene experts say CB models, through a hierarchy of control, provide a basis to determine the broad hazard group to which a chemical belongs and its necessary level of control – but they caution that the method has limitations.

In recent months, discussion has taken place about how CB guidance can be incorporated into a ruling to amend OSHA’s hazard communications standard to align with the United Nations’ Globally Harmonized System of Classification and Labelling of Chemicals. Researchers and safety and health practitioners also have been exploring expanded application of CB beyond chemicals. Experts predict CB application and training demand will increase as the number of chemicals in use globally grows and new occupational hazards emerge.

Not a new concept

Much of the research on the CB method has taken place in the past decade, but the concept has been around since the late 1980s, when the pharmaceutical industry used the process to measure exposure to highly potent chemicals. In the 1990s, the United Kingdom’s Health and Safety Executive set the stage for current research with development of the Control of Substances Hazardous to Health regulations, better known as COSHH Essentials. COSHH Essentials uses risk phrases from European Union labels and safety data sheets to control for hazards. Although other countries have developed variations of models, COSHH Essentials has become the preferred model.

According to NIOSH researchers, interest in CB models has increased in recent years due to the growing number of chemicals in the global market – thousands of which do not have occupational exposure limits. According to NIOSH, it is not possible to have OELs for every chemical, chemical mixture, fume or emission.

Richard Niemeier, a senior scientist and toxicologist for NIOSH, said CB usually is applied at larger enterprises, but some small and medium-sized organizations are exploring the opportunity to use the model. CB models help limit exposure to chemicals by allowing workers to simply plug in some basic information and come up with an engineering control, Niemeier said.

Niemeier and T.J. Lentz, lead health scientist for NIOSH, say the scientific community also has been considering expanding CB applications. Potential models are being considered for construction, health care, psychosocial factors, environmental applications, ergonomics and safety management. In addition, application is being considered for emerging hazards such as nanomaterials and nanotechnology.

Although NIOSH supports the exploration of CB use, some are hesitant to apply a technique developed in the pharmaceutical industry to other industries. Robert Sussman, managing principal for SafeBridge Consultants Inc.’s Eastern Operations in New York, said all industries should be cautious about using CB models without expert guidance. The system is very useful for categorizing and controlling exposures to chemicals with unknown or limited information on their toxicity; ultimately, however, manufacturers of chemical substances should want to compare a number derived more quantitatively, Sussman said. He also warned against large companies relying too heavily on the COSHH Essentials model, saying it “was designed for small and medium-sized enterprises without the health and safety resources to appropriately categorize chemical substances using internal staff.”

The good and the bad

Research has shown that CB limitations include over- or under-control for occupational hazards. Other challenges for small businesses relate to a lack of resources to implement CB models, availability of information, and difficulty in interpreting risk phrases and model application. During a 2004 meeting of the World Health Organization, presenters said barriers to effective implementation of control strategies such as CB exist mainly due to a “knowledge-application gap.” Barriers include insufficient awareness, education and political will; lack of human and financial resources; deficiencies in information or communication among professionals and institutions; inadequate preventive approaches; and failure to involve workers and their representatives directly in problem solving. Despite these limitations, CB is a valuable health and safety training tool, and can be used to complement and enhance the traditional occupational exposure level approach to risk assessment, said Anne Bracker, an industrial hygienist at the University of Connecticut Health Center in Farmington.

“When you don’t have a permissible exposure level or resources for a first-line approach, control banding could help at least screen what you might want to look at more carefully or identify needs right off the bat,” Bracker said, but warned that the model is “not a cookbook.”

A study by Bracker and colleagues Timothy F. Morse and Nancy J. Simcox, published in the Journal of Occupational and Environmental Hygiene (Vol. 6, No. 5), examined the effectiveness of training curriculum for the COSHH Essentials model. As part of the study, individuals from 34 worksites attended a control banding workshop and learned how to use the COSHH Essentials model. Participants from 10 of those worksites agreed to use COSHH Essentials to evaluate at least one task. A certified industrial hygienist then visited the workplaces and evaluated the same task. Study results showed that when applied in the workplace, the model agreed with both the certified industrial hygienist’s and the participant’s worksites’ qualitative risk assessment 65 percent of the time and likely over-controlled in 71 percent of the non-agreement cases.

“The model was very effective in getting people to talk about risks beyond just single permissible exposure limits,” Bracker said. Participants cited limitations such as difficulty researching risk phrases, locating control guidance sheets, working with mixtures and trusting the model for some tasks it either over- or under-controlled. Still, the CB models and training helped participants identify chemicals that could be substituted with safer alternatives, Bracker said.

Guidance published by NIOSH in 2009, “Qualitative Risk Characterization and Management of Occupational Hazards: Control Banding,” warns that CB can be used for many occupational hazards, but is not effective for all occupational hazards and does not replace industrial hygiene expertise or traditional exposure monitoring and use of OELs. The Centers for Disease Control and Prevention said CB currently is not appropriate for many situations, including “hot” processes, open spray applications, gases and pesticides. In addition, Sussman, who has more than 20 years of experience in the pharmaceutical industry, warns of one common misuse of CB – stopping once a band has been assigned. “You really need to continue and develop quantitative exposure limits as sufficient data become available,” he said, adding that in the end, organizations need industrial hygiene data to support the particular control measures they have implemented.

Bracker suggested using CB as one component of a comprehensive safety and health program that includes best practice guidance and a searchable library for both CB materials and guidance from certified industrial hygienists. She also suggested developing standardized hazard statements and promoting hazard communication standard alignment with GHS. The American Society of Safety Engineers also has promoted the use of CB and GHS. In December 2009, almost three months after OSHA published a notice of proposed rulemaking that would revise the hazard communication standard to conform with GHS, ASSE sent a letter to OSHA administrator David Michaels, urging his agency to consider inclusion of CB model elements in the revised standard.

Application potential

If alignment of the hazard communication standard and GHS takes place and all requirements go into effect, OSHA estimates the changes will result in the prevention of 318 non-lost workday injuries and illnesses, 203 lost workday injuries and illnesses, 64 chronic illnesses and 42 fatalities annually. The agency acknowledges CB as a tool to provide guidance for control measures for chemical exposures. But because CB relies on harmonized hazard statements to allow the system to estimate the degree of severity of the hazard, OSHA said use of CB for chemical safety and health approaches in U.S. workplaces cannot be accomplished until adoption of GHS makes harmonized hazard statements readily available.

“Adoption of the GHS and its phrases would open up the possibility that control banding guidance can be used in the U.S. to help small and medium-sized employers select and implement appropriate control measures,” the notice of proposed rulemaking states. OSHA scheduled two public hearings on GHS in March; at press time, a third was set to take place April 13 in Los Angeles.

OSHA estimates more than 40 million employees are potentially exposed to thousands of hazardous chemicals in use in the more than 5 million workplaces in the United States. The most recent statistics from the Bureau of Labor Statistics show an estimated 55,400 employee illnesses in 2007 could be attributed to chemical exposures, as well as 17,340 chemical-source injuries and illnesses that involved days away from work. OSHA warns these statistics are only a small percentage of a much larger worker exposure and illness problem.

CB resources in development

As more CB research is done, and if the variability of CB models improves, solutions to limitations might not be so far away. A number of professional associations already have made progress on developing several resources for small and medium-sized enterprises, according to Lentz and Niemeier.

In 2005, NIOSH recommended tasking a national CB working group with creating a validation process for evaluating existing toolkits. A number of professional industrial hygiene associations already have formed working groups to develop effective CB strategies.

Lentz said various CB resources for small and medium-sized organizations are in development. NIOSH has been investigating potential applications and participated in a number of international and national CB workshops. NIOSH also has partnered with professional organizations to offer practical guidance for small and medium-sized enterprises. In 2007, NIOSH partnered with the American Industrial Hygiene Association to develop a practical guide on CB, “Guidance for Control Banding Analysis.” Progress also is being made by organizations to complete online databases for chemicals, while NIOSH is continuing to work on DVD training modules and a CD-ROM, Lentz said.

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