Date: Sun, 14 May 2006 15:43:39 -0400
Reply-To: Ralph Stuart <rstuart**At_Symbol_Here**uvm.edu>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: Ralph Stuart <rstuart**At_Symbol_Here**uvm.edu>
Subject: Vermont Monitor Article
Comments: To: SAFETY**At_Symbol_Here**LIST.UVM.EDU

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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