Introduction
The Industrial Hygiene/Occupational Safety Special Interest Group (IH/OS SIG) Steering Committee met on January 31, 2012 through a conference call meeting. IH/OS SIG Steering Committee Chair Bob Kapolka, Oak Ridge Institute for Science and Education (ORISE), facilitated the meeting in which the following Steering Committee members/guest participated:
Saul J. Chessin, Idaho National Laboratory
Andria Dutcher, S.M. Stroller
Bill Frede, Honeywell FM&T
Ralph Hinterman, Argonne National Laboratory
George Holdsworth, ORISE
Bob Kapolka, ORISE
Dan Marsick, Department of Energy (DOE)
Deborah McFalls, ORISE
Rob Nicholas, Los Alamos National Laboratory (LANL)
Charles Olaiya, DOE
Elliot Stein, DOE
Michael Teresinski, DOE
Robert Weeks, LANL
David Weitzman, DOE
Plumbing Cross Connections and Backflow Prevention Program
Committee Member Elliot Stein gave a presentation concerning laboratory plumbing system backflow prevention and cross connection program components. Topics discussed included reasons for having a back flow/cross connection prevention program and protection of potable water supplies from contamination:
CDC estimate of magnitude of problem in U.S.:
From 1981 to 1998, CDC documented 57 waterborne disease outbreaks related to cross connections, resulting in 9,734 illnesses:
20 outbreaks (6,333 cases of illness) caused by microbiological contamination
15 outbreaks (679 cases of illness) caused by chemical contamination
22 outbreaks (2,722 cases of illness) where the contaminant was not reported
Reasons why contamination events may be under-reported:
Outbreaks of illness may not be linked to an incident of backflow contamination.
Documented effects of contamination are usually acute and result from short-term exposures; whether mild or severe, the effect appears soon after exposure. Effects that are long-lasting or only appear after some time (chronic effects) are difficult to ascribe to a single event or associate with a waterborne source.
Cross-connections combined with uncorrected backflow situations that cause continuous or intermittent exposure over a long time and result in chronic illness would be less likely to be linked to backflow contamination.
Contamination may not affect enough people to attract the attention of public health officials.
Information that could tie an incident to an outbreak of illness or disease, such as where and when a contaminant entered the system, is often missing.
Legal requirements:
EPA Safe Drinking Water Act 1974 (latest amendment 1996)
Illinois Health/Plumbing Code (Sections dealing with cross connections/backflow protection):
Title 77: Public Health
Chapter I: Department of Public Health
Subchapter r: Water and Sewage
Part 890 Illinois Plumbing Code
OSHA 1926.51(b)(2)
Types of cross connections:
Backflow is the undesirable reversal of flow of water or other substances or mixtures into the drinking water distribution system.
Back siphonage is caused by negative pressure (vacuum) in the supply line. This effect is similar to sipping a coke by inhaling through a straw, which induces a flow in the opposite direction.
Back pressure is caused by higher pressure in the system than is in the supply line. This can be caused by turning on a pump in the system that has a higher pumping pressure than that of the supply line. If the pump line is contaminated with a hazardous chemical, the higher pressure in the system could force the hazardous chemical back into the supply line or water main.
Definitions of backflow, back pressure and back siphon effects and submerged inlet and low inlet,
Types of back flow prevention devices (air gaps, atmospheric vacuum breakers, pressure vacuum breakers, double check valves, reduced pressure principle backflow preventers or reduce pressure zone),
Historic examples of back flow and cross connection potable water contamination events effecting occupational and public health,
Examples of cross connections that can lead to backflow (whenever a plumbing fixture is connected to the drinking water supply, a potential cross-connection exists):
Wash basins and service sinks
Laboratory equipment
Irrigation or lawn sprinkler systems
Swimming pools and spas
Solar heat systems
Fire sprinkler systems
Auxiliary water supplies (wells, storage tanks and second feeds)
Photo developing equipment
Chemical feed equipment
Attachment to hoses to apply weed killer or fertilizer or to flush antifreeze
Food and beverage processing equipment
Ornamental fountains
Boilers
Hose bibs
Highlights of the New Brunswick Laboratory backflow cross connection inspection.
Elliot also mentioned that the Oak Ridge National Laboratory’s (ORNL) program components as a model related DOE program. Information about ORNL’s program (Cross-Connection Control of the Potable Water Lines at Oak Ridge National Laboratory) can be found at: www.osti.gov/bridge/servlets/purl/245651-tMFANM/webviewable/.
Hazard Banding Initiative
George Holdsworth, ORISE, provided information about the National Institute for Occupational Safety and Health (NIOSH) efforts in leading an interagency project to assign occupationally important chemicals to bands that represent the perceived threat to human health.
The initiative seeks to address the problem that establishing occupational exposure limits (OELs) for important industrial chemicals is a long process and new products and formulations are being produced all the time by the chemical industry. Consequently, the agencies with responsibility for protecting the health of workers are continually behind in their efforts to set protective standards. This increases the likelihood that persons may be unwittingly exposed in the workplace to harmful substances for which no exposure guidelines exist.
Hazard Banding is conceived as a semi-quantitative approach to toxicological and human health evaluations that uses existing data to place a chemical into categories (or “bands”) representing incremental levels of threat to human health through occupational exposure. A five band system is usually proposed, A–E, with “E” being the most precautionary.
Advantages to the hazard banding approach include:
Chemicals can be assessed more quickly than using traditional methods,
Setting chemicals into bands will serve to establish priorities for initiating full assessments, and
Placing chemicals into bands will serve as a guide for what industrial hygiene measures may be necessary to protect occupationally exposed individuals.
NIOSH has sponsored a number of teleconferences and a November 2011 workshop to endeavor to establish how hazard banding could be achieved.
An important consideration of any such scheme is that the approach should be sufficiently consistent that (1) the same result would emerge whoever is running the methodology, and (2) the hazard banding results must be scientifically defensible. In the future, an expert system may even be possible.
Much of the preliminary work on the approach has been to conceptualize which toxicological endpoints should impact band selection and what qualitative, semi-quantitative, and quantitative criteria should apply to each endpoint that would contribute to band selection.
One problem with the approach is that, in the case of a substantial number of chemicals, it may be anticipated that there will be a paucity of information for band setting. Consequently, the approach assumes that if insufficient agent-specific information is available to place a chemical in a band, it will be placed, by default, into a comparatively precautionary band (for example, band D).
As information becomes available, the question then arises as to how much data will be necessary to justify removing a chemical from the default band and placing it into one that is less precautionary.
The different toxicological and human health endpoints that represent appropriate categories of information for input into the hazard banding process are shown in the following table along with sources of information for setting criteria to establish the endpoint specific bands:
Examples of Qualitative and Quantitative Criteria for Each Toxicological Endpoint
The general approach, and the need to consider an array of endpoints in setting bands, has been discussed in relation to the toxicity of the important industrial chemical, n-hexane. The LC50 of the chemical is high (48,000 ppm for a 4-hour exposure in rats) possibly indicating that a less precautionary band (A?) might be appropriate. However, a myriad of occupational exposure studies in persons using adhesives with n-hexane as the solvent has suggested that such persons are especially vulnerable to the development of peripheral neuropathy with continued use. A NIOSH REL and an EPA reference concentration (RfC) with this effect as the driver, would indicate a toxicological benchmark of 50–67 ppm to be more appropriate to capture the toxicity of the substance. This would suggest that a more precautionary band (C?) might be more appropriate for this chemical.
The next steps in the iterative process for establishing hazard bands (phased approach) might include:
Establishing a protocol for deciding whether available chemical-specific data are sufficient for hazard banding, and
Developing a decision logic that would allow plausible choices for the bands to be made in a consistent and defensible basis.
With regard to the first issue, it is possible to see an approach by which the various toxicological endpoints could be weighted, and the presence of established criteria for each endpoint could be scored with any number (present) or zero (absent). The products of criterion scores and endpoint weights could then be added together for a total determinant score that could be compared to a pre-determined threshold score. If the total determinant score were to exceed the threshold score, the data would be considered sufficient for hazard banding purposes. Running the methodology with a diverse suite of toxicants would be necessary to test the sensitivity of the methodology, with the possibility of changing the weights, scores, and threshold scores as necessary.
Concerning the second issue, important questions to be considered as the feasibility of the methodology is evaluated, include:
Whether the weight of the toxicological endpoint should have a role in its overall scoring for band setting purposes?
Assuming that the process gives rise to a number of candidate hazard bands, how does one choose among them?
Alternatively, should one assume that that hazard bands should be set cumulatively, as may be possible by considering a range of toxicological impacts?
Should the likely extent of exposure be factored into band selection?
Should the approach endeavor to address mixtures, and, if so, how?
It is anticipated these issues/concerns will be considered during the implementation process of the NIOSH health hazard banding initiative.
Globally Harmonized System
Committee Member Bob Weeks shared information about the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) that is a system planned for publication in the Federal Register in February 2012. The system was developed by the United Nations based on needs established by the International Labor Organization. The reason for the development of such a system is simply because of the number of inconsistencies in the classification and labeling of chemicals within a particular country, e.g., the USA and moreover between countries. With today’s ever growing global economy (global chemical business is >$1.7 trillion) per year, there is a need for consistency to address hazards and to provide protective measures, such as personal protective equipment and labeling, to protect against these hazards. Implementation of the GHS will provide the public and workers with a greater awareness of chemical hazards as well as simplified communications and practices for the safe handling and use of hazardous chemicals.
The GHS covers all hazardous chemicals. The need for GHS labels will vary by product category and/or by the particular stage in the chemical’s life cycle, including the many steps from research to production to end use.
The GHS “physical” hazards are:
Explosives
Flammable Gases
Flammable Aerosols
Oxidizing Gases
Gases under Pressure
Flammable Liquids*
Flammable Solids*
Self-Reactive Substances
Pyrophoric Liquids
Pyrophoric Solids
Self-Heating Substances
Substances which, in contact with water emit flammable gases
Oxidizing Liquids
Oxidizing Solids
Organic Peroxides
Corrosive to Metals
*The flammable liquids/solids categories merit notice. In particular the category hazard numerical order is just the opposite of that used in the NFPA diamond. For example a one (1) in the flammability section of the NFPA diamond is a low flammability hazard, i.e., flash point >200 ⁰ F and a one (1) in the GHS system is a high hazard, flash point < 23⁰C (73⁰F).
The GHS “health” hazards are:
Acute Toxicity
Skin Corrosion/Irritation
Serious Eye damage/Eye Irritation
Respirator or Skin Sensitization
Germ Cell Mutagenicity
Carcinogenicity
Reproductive Toxicology
Target organ Systemic Toxicity- Single Exposure
Target Organ Systemic Toxicity-Repeated Exposure
Aspiration Toxicity
The GHS “environmental” hazards are:
Hazardous to the aquatic environment
Acute aquatic toxicity
Chronic aquatic toxicity
Bioaccumulation potential
Rapid degradability
Each of the aforementioned categories is defined in the GHS documentation and such defining is beyond the scope of the present synopsis. The GHS documentation gives examples of the labels/pictograms for the various categories.
The Safety Data Sheets (SDS) required by the GHS take the place of existing MSDSs and there are both similarities and differences between the existing MSDS content and format and the content and format of the GHS SDS. As before, the GHS documentation elaborates on these differences.
The GHS states in Chapter 1.4, Section 1.4.9, the importance of graded training levels for all target audiences such that they can recognize and interpret label and/or SDS information, and take appropriate action in response to chemical hazards. The 29 CFR 1910.1200(h) “Employee information and training” appears to be more prescriptive than the 1.4.9 previously cited. Whether this continues to be the case will be shown when the revised 29 CFR 1910.1200 is published, most likely during February or the early spring of 2012.
There is limited guidance in the GHS related to personal protective equipment.
Globally Harmonized System of Classification and Labelling of Chemicals (GHS) (“The Purple Book”) (www.osha.gov/dsg/hazcom/ghs.html)
DOE News
DOE Official Dan Marsick reported that the “Joint EFCOG/DOE Chemical Management and Worker Safety and Health Program (10 CFR 851) Workshop” will be held March 13-15, 2012, in Washington, DC at the DOE Forrestal Headquarters Auditorium. People who cannot attend the workshop in person can participate via video conference and/or teleconference which will be available. One of the presentations at the workshop will be on implementation of the Globally Harmonized System discussed during this meeting. Information about the workshop can be found at: www.hss.doe.gov/HealthSafety/WSHP/chem_safety/ws2012/.
DOE Official David Weitzman reported that the annual “DOE and DOE Contractors Industrial Hygiene Meeting” will be held in conjunction with the 2012 AIHce this year. Date of the meeting has not been determined at this time. The meeting will be available via the Webinar for the first time this year. The IH/OS SIG will be a co-sponsor of the meeting.
Future Steering Committee Conference Call Meeting
The next IH/OS SIG Steering Committee meeting is scheduled for March 6, 2012, 1:15 – 2:45 pm EST. An agenda and the conference call number will be sent to the committee prior to the meeting.
For additional information, please contact: Deborah McFalls, IH/OS SIG Coordinator
Oak Ridge Institute for Science and Education
P. O. Box 117, MS 10
Oak Ridge, TN 37831-0117
Globally Harmonized System of Classification and Labelling of Chemicals (GHS) (“The Purple Book”) (