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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 ìDo You Know What Youíre
Breathing? Exposure Assessment Strategies in Research Labs,î 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 ìcontrol
banding,î a system for selecting worker protection strategies based
on grouping chemicals into ìbandsî or classes of chemicals of similar
toxicity and selecting ìcontrolsî 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-1980ís.
For example, one of the presentations in the symposium discussed the
coming (scheduled for 2008) ìGlobally Harmonized System [GHS] for the
Classification and Labeling of Chemicalsî 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 MSDSís
Material Safety Data Sheets were originally established as an OSHA
requirement for the shipbuilding industry in the early 1970ís. In
those days, MSDSís 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, OSHAís hazard communication standard was promulgated,
requiring access to MSDSís for all hazardous chemicals used in U.S.
workplaces. The OSHA standard required that suppliers provide MSDSís
to any employer who bought the chemicals for use in their workplace.
However, employers retained the responsibility for assuring that the
MSDSís provided adequate information to support chemical safety
training in their workplaces. Thus, those benefiting from MSDSís were
not the same people who were writing them.
For this reason, MSDSís were carefully worded to prevent potential
liability to the chemical manufacturers and supp-liers. The MSDSís
became legal documents whose content was generally limited to a
handful of stock warning phrases about ìusing appropriate practicesî
and ìconsulting local regulations,î which were of little practical
value. A variety of commercial suppliers of MSDSís stepped into the
resulting void by writing MSDSís 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 MSDSís. This format was designed to
improve their usefulness to employers. However, the resulting format
included 16 sections, which meant that while many MSDSís 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 MSDSís available.
The Globalization of MSDSís
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 ìThe Globally Harmonized System for
the Classification and Labeling of Chemicals.î
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 ìRisk Phrasesî (known as R-phrases) to
standardize hazard communication. Risk Phrases are a collection of 68
warnings (for example ìR1 Explosive when dryî or ìR40 Limited
evidence of a carcinogenic effectî) 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
chemicalsóidentifying the necessary control measures associated with
the chemicalsówhich brings us to the topic of ìcontrol banding.î
Control Banding
Control Banding, as Iíve 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 ìbandî 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 ìControl of
Substances Hazardous to Health Regulationsî 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:
ï Screen 1: Identification of the process and tasks involved
ï Screen 2: Definition of how many chemicals you are using
ï Screen 3: Identification of the chemi-cal(s) or product name(s)
ï Screen 4: Assessment of the hazard group for the chemical(s) based
on the risk statement on the MSDS
ï Screen 5: Assessment of how likely the chemical is to get into the air
ï Screen 6: A description of how much of a chemical you are using and
how often you are using it
ï Screen 7: Review of user input
ï 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 ìready, fire, aimî
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 industryóincluding the ever-expanding number of
pharmaceutical materials, nanotechnology and new biological materialsó
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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