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This is an article that I wrote that was published in the Vermont Environmental Monitor. You can get more information about the Monitor from http://www.enviro-source.com - Ralph Hazard Communication and Industrial Hygiene in the 21st Century By Ralph Stuart I recently attended the national meeting of the American Chemical Society in Atlanta. The program of the Chemical Health and Safety Division included a symposium entitled “Do You Know What You’re Breathing? Exposure Assessment Strategies in Research Labs,” which focused on the practical issues involved in determining how to appropriately protect workers from the toxicity of chemicals for which little toxicity information is available. The strategies discussed revolved around the concept of “control banding,” a system for selecting worker protection strategies based on grouping chemicals into “bands” or classes of chemicals of similar toxicity and selecting “controls” such as local ventilation or personal protective equipment based on which band a particular chemical fits in. Thinking about these presentations led to me reflect on how industrial hygiene has evolved since OSHA passed the hazard communication standard in the mid-1980’s. For example, one of the presentations in the symposium discussed the coming (scheduled for 2008) “Globally Harmonized System [GHS] for the Classification and Labeling of Chemicals” and how GHS relates to the control banding approach. This global system for communicating chemical hazards will result in international standards for the contents and format of Material Safety Data Sheets (MSDS), the basic building blocks of industrial hygiene programs used since the OSHA hazard communication standard was promulgated. In this column I will review the evolution of hazard information since the Hazard Communication Standard has gone into effect, describe what control banding means in practical terms, and provide web links for people interested in learning more about these tools. A Brief History of MSDS’s Material Safety Data Sheets were originally established as an OSHA requirement for the shipbuilding industry in the early 1970’s. In those days, MSDS’s were specifically designed to be useful for the materials that create health and environmental problems around shipyards, primarily paints, oils and asbestos. OSHA developed a specific format for MSDS based on those types of chemicals, and that format was useful only to this setting. For example, a key section of the format dealt with the potential for marine pollution associated with the chemical product. In 1987, OSHA’s hazard communication standard was promulgated, requiring access to MSDS’s for all hazardous chemicals used in U.S. workplaces. The OSHA standard required that suppliers provide MSDS’s to any employer who bought the chemicals for use in their workplace. However, employers retained the responsibility for assuring that the MSDS’s provided adequate information to support chemical safety training in their workplaces. Thus, those benefiting from MSDS’s were not the same people who were writing them. For this reason, MSDS’s were carefully worded to prevent potential liability to the chemical manufacturers and supp-liers. The MSDS’s became legal documents whose content was generally limited to a handful of stock warning phrases about “using appropriate practices” and “consulting local regulations,” which were of little practical value. A variety of commercial suppliers of MSDS’s stepped into the resulting void by writing MSDS’s for specific chemicals, but chemical safety information for mixtures of chemicals continued to be only as useful as the supplier of the chemical was willing to make then. In 1998, the American National Standards Institute established a standard for the format of MSDS’s. This format was designed to improve their usefulness to employers. However, the resulting format included 16 sections, which meant that while many MSDS’s were longer, they were not necessarily more understandable to the average worker. OSHA recommends that the ANSI format be utilized, but it cannot mandate it without federal regulation changes, so the ANSI standard has had a limited effect on the general quality of MSDS’s available. The Globalization of MSDS’s At the Earth Summit in Rio de Janeiro in 1992, the international community recognized the problem of non-standard MSDS information, which is particularly acute internationally and across language barriers. An agreement to address this issue was signed at the Summit. Since the Rio conference, a variety of countries (including the U.S., China and Canada, as well as most of the European countries) have been developing “The Globally Harmonized System for the Classification and Labeling of Chemicals.” The Globally Harmonized System is not a model regulation; rather, it is a framework which national regulators can use to develop a system of appropriately harmonized classification and communication requirements for chemical hazards that will be internationally recognized. The GHS consists of two primary elements: standard criteria for classifying chemical substances and mixtures according to their health, environmental and physical hazards; and harmonized hazard communication elements, including requirements for labeling and material safety data sheets. At the national level, these elements may be used as building blocks from which a revised hazard communication regulation can be built that can be recognized internationally. National authorities, such as OSHA, will determine how to implement the elements of the GHS within their current regulatory systems. The goal is to have an international system fully operational by 2008. A document that compares the GHS elements to the current OSHA Hazard Communication Standard is available on the web at http://www.osha.gov/ dsg/hazcom/ GHSOSHAComparison.html. At the practical level, the GHS is likely to follow the current European model of using “Risk Phrases” (known as R-phrases) to standardize hazard communication. Risk Phrases are a collection of 68 warnings (for example “R1 Explosive when dry” or “R40 Limited evidence of a carcinogenic effect”) that address either physical or toxic effects of a chemical. The European Union (EU) requires that risk phrases appear on each safety data sheet for hazardous chemicals. More than one R-phrase may appear on an MSDS. These are usually presented in specific combinations, such as R36/37/38. In general, no more than four R- phrases should be sufficient to adequately communicate the risks of a particular material. The GHS approach lends itself to the development of a standard label for chemical containers that can provide internationally recognizable warnings about the hazards of the chemicals contained within. A system of clear warnings supports the next step in the safe use of chemicals—identifying the necessary control measures associated with the chemicals—which brings us to the topic of “control banding.” Control Banding Control Banding, as I’ve described earlier, is an approach to protecting worker health that focuses on a standard set of exposure controls such as personal protective equipment or local ventilation. Control Banding is necessary because the number of chemicals in industrial use is outpacing the ability to completely assess their hazards: developing a specific Occupational Exposure Limit for every chemical in use would be impossible. By identifying a “band” for control measures based on the hazard classification of a chemical, the amount of chemical in use, and its volatility/dustiness, it is possible to readily identify the precautions for using that chemical. The control band approach is most useful with health hazard data, because the toxicity information that is available can be seriously incomplete or very difficult to interpret because it is based on animal data. The outcome of the control banding process is identification of one of four general control strategies for the use of this chemical: 1 Employing good industrial hygiene practice (i.e. maintain standard housekeeping standards); 2 Using local exhaust ventilation (to provide protection from the airborne chemical); 3 Enclosing the process (to control potential skin exposure to the material by facilitating housekeeping); or 4 Seeking the advice of a specialist for the use of this chemical. More specific information about the challenges and potentials of the control banding approach can be found at the NIOSH web site at http:// www.cdc.gov/niosh/ topics/ctrlbanding/. Table 1, which provides general guidance for setting up control bands based on the inhalation hazard associated with chemicals, comes from this page. The COSHH Essentials Web Site An example of using the control banding idea is the “Control of Substances Hazardous to Health Regulations” web site in the United Kingdom. Found at http://www.coshh-essentials.org.uk/, the web site is provided by the UK Health and Safety Executive (their equivalent of OSHA) and is designed to provide generic health and safety advice to small and medium businesses. The COSHH Essentials process provides advice on controlling the use of chemi- cals for a range of common tasks, for example mixing or drying a combination of materials. The website takes you through a number of steps and asks for information about your tasks and chemicals. These steps include: • Screen 1: Identification of the process and tasks involved • Screen 2: Definition of how many chemicals you are using • Screen 3: Identification of the chemi-cal(s) or product name(s) • Screen 4: Assessment of the hazard group for the chemical(s) based on the risk statement on the MSDS • Screen 5: Assessment of how likely the chemical is to get into the air • Screen 6: A description of how much of a chemical you are using and how often you are using it • Screen 7: Review of user input • Screen 8: Advice on how to protect yourself and others Once completing this information, the web site will provide general information sheets describing appropriate protection strategies. This process does not provide industrial hygiene or engineering advice specific to your workplace, however, it can provide general guidance about the protection strategies appropriate to your workplace. Conclusion Control banding has been described as taking a “ready, fire, aim” approach to worker protection because it presupposes that the health hazards associated with a chemical can be reasonably summarized by appropriate risk phrases. This assumption requires that environmental and/or biological sampling be done after work with the material has started, in order to assure that the chosen protection strategy is in fact working. For highly toxic materials, this may not be an acceptable approach to hazard control, so the limits of control banding should be carefully examined before work with these materials begin. However, as more and more new materials with uncertain hazards are being used in industry—including the ever-expanding number of pharmaceutical materials, nanotechnology and new biological materials— it makes sense to take advantage of the experience of 20th century industrial hygiene. Its ever-improving ability to recognize the hazards of industrial processes helps inform the process of protecting workers as efficiently as possible. Ralph Stuart, CIH, is Environmental Safety Manager at the University of Vermont, and is a frequent contributor to the HazMat Clinic.
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