A. Syverson, Duke Energy, Houston, TX; A. Almaguer, Duke Energy, York, SC.
Situation: Reactor coolant containing hexavalent chromium leaked in the reactor building. Such leaks typically go to sumps and system volume is replenished. The leaks pose no radiological hazards. However, the coolant leaked directly onto the 650ºF nuclear reactor, flashed to steam, resulting in dusts containing hexavalent chromium. The dusts were spread by the ventilation system causing concerns of overexposures.
Problems:
Resolution:
How will sharing this work experience benefit other practitioners? This is a good example of escalating emotions overriding hard data, and PPE and air sampling “overkill” driven by personnel perception. It is an example of how honest communication can avert a media nightmare and work stoppage.
C. Torres, Intel Corporation, Colorado Springs, CO; S. Brown, Intel Corporation, Hillsboro, OR.
This presentation will outline the discovery of unknown asbestos-containing materials (ACM) used at various Intel manufacturing locations and our response to this discovery. The ACM was in the form of gaskets used on manufacturing equipment that was currently and previously maintained periodically in a manner that would disturb the asbestos-containing material. In the course of the presentation the following topics will be addressed. The situation: the means of discovery, initial responses to EHS and manufacturing concerns, long-term plans to replace ACM gaskets in accordance with current best practices to protect workers’ health and safety and per regulatory guidance, and development of exposure assessment strategies to characterize potential historical, present, and future exposures to asbestos fibers. The problems: how to interpret regulatory (OSHA) guidance as to which standard we should follow (general industry vs. construction), how to quantify potential historical exposures while protecting workers and meeting regulatory requirements, how to communicate newly-found hazards to current and past employees performing maintenance on tools containing ACM gaskets, and how to address long-term EHS concerns without materially impacting manufacturing operations. The resolutions: an explanation of how we determined OSHA Construction Standard (1926.1101) was most applicable to our situation even though we were conducting sustaining operations, a review of the exposure assessment strategies employed, presentation of communication strategy implemented for workers (past and present) and management, and a look at the long-term plan implemented to effectively replace ACM gaskets while upholding regulatory and EHS concerns. Finally, the presentation will address benefits to others such as forming a strategy to handle newly-discovered hazards in the workplace, development of a historical exposure assessment strategy, and an approach to regulatory review and interpretation.
J. Kangas, J. Laitinen, Kuopio Regional Institute of Occupational Health, Kuopio, Finland; M. Hautamäki, M. Hyttinen, P. Pasanen, P. Kalliokoski, University of Kuopio, Kuopio, Finland; S. Batterman, University of Michigan, Ann Arbor, MI.
A large portion of printing industry workers are exposed to organic solvents due to the use of isopropanol in the fountain solution of the press and cleaning solvents. Recently, several printing plants have started to use vegetable oil-based products as washing solvents. The aim of this work was to evaluate workers’ exposure to solvents in 10 offset plants and study the influence of vegetable-based oil to the exposure. In addition, passive and active methods were compared for monitoring the exposure of the workers.
Personal samples were taken from 1–3 printers during one work shift. Both active sampling with activated carbon tubes and passive sampling with thermal Tenax GR desorption tubes were employed. The active samples were desorbed with carbon disulfide and analyzed with GC/FID. The passive samples were analyzed with GC/MS after thermal desorption.
The average concentrations of isopropanol and solvent naphtha were 59.4 and 85.7 mg/m3 in personal samples, when cleaning was done with solvent naphtha-based product. The use of vegetable oil-based cleaning solvent reduced the average concentration of isopropanol to 25.4 mg/m3 and solvent naphtha to 13.5 mg/m3. The average combined solvent exposure effect was 0.25 in the printing plants using naphtha-based cleaning solvent measured with passive sampling and 0.24 when active sampling was used. In printing plants where vegetable oil-based products were used, the corresponding combined effects were 0.06 and 0.05.
The occupational solvent exposure levels were generally not insignificant but at or above 10% of the OEL. Only in two plants, where vegetable-based cleaning agents were used, were the exposure levels less than 10%. The use of vegetable oil-based cleaning fluids was observed to be an efficient way to reduce exposure. On average, the passive sampling method yielded slightly higher concentrations than the active sampling method.
V. Belfit, U.S. Army CHPPM, Bel Air, MD.
The U.S. Army Center for Health Promotion and Preventive Medicine (USACHPPM) conducted a 6 month health consultation to address management and worker concerns of alleged health hazards associated with exposure to Dichlorodiphenyltrichloroethane (DDT) in a Department of Army Building. From 1949 to 1952, a commercial chemical company processed and stored DDT and other pesticides in this building, before it was converted to a government administrative building. The Agency for Toxic Substances and Disease Registry and the State Department of Public Health had previously conducted health evaluations of the building. Both studies concluded the building was safe to occupy. However, the building workers and management continued to have many concerns, and requested USACHPPM conduct an independent health evaluation. USACHPPM employed a matrixed team to deal with this problem, involving experts from many different technical specialties, including industrial hygiene, occupational and environmental medicine, and health risk assessment. USACHPPM concluded that levels of DDT are safe for office workers in air, drinking water, and surfaces in commonly-used areas. However, the concrete subfloor had levels of DDT of concern for personnel conducting activities such as electrical conduit installation in subfloor areas on a regular basis and physically contacting the concrete surface. USACHPPM recommended a more extensive evaluation of the subfloor be conducted to determine if additional personal protective measures should be implemented. Recommendations also included cleaning the subfloor areas of rooms where sampling results showed elevated levels of DDT; wearing disposable gloves when working in subfloor spaces until a more in-depth evaluation is accomplished; encapsulating interior concrete surfaces with a methyl methacrylate polymer encapsulant; annually inspecting and maintaining the encapsulant as long as the building is in use; and enforcing good housekeeping, cleaning, and personal hygiene practices.
L. Conroy, J. Plavka, T. Schoonover, D. Vinson, S. Erdal, University of Illinois at Chicago, Chicago, IL.
The Occupational Safety and Health Administration (OSHA) recognizes welding, cutting, and brazing as hazardous activities that pose health and safety risks to over 500,000 workers in a wide range of industries. There are several types of welding with some welding practices presenting a higher health hazard because of the type of metal being welded, the area the weld is performed in, and the type of electrode used. This paper describes an exposure assessment for ozone and nitrogen dioxide in a large manufacturing facility. The study involved measuring ozone and nitrogen dioxide, using Ogawa passive samplers, in 16 welders and 19 non-welders. Each worker’s exposure was measured over the entire work shift.
Ozone concentrations were significantly higher in the welding group (mean concentration 10.3 vs. 3.86 ppb, p = 0.03). Nitrogen dioxide concentrations were significantly higher in the welding group at the alpha = 0.1 level (mean concentration 66 vs. 47.2 ppb, p = 0.098). Within the welding group, there were three subgroups, GMAW/SMAW, GTAW, and maintenance welding. The GTAW group welded on stainless steel. While the number of subjects is too small to see significant differences, ozone concentrations were highest in the GMAW/SMAW group followed by maintenance welding, with GTAW resulting in the lowest concentrations (12.4 vs. 1.84 vs. 0.61 ppb, respectively). For nitrogen dioxide, the GTAW had the highest exposures followed by the GMAW/SMAW group, with maintenance welding resulting in the lowest concentrations (50.0 vs. 49.4 vs. 32.6 ppb, respectively).
The welding fumes are a complex mixture of particulates and irritant gases. This study illustrates that one needs to evaluate gaseous exposure along with particulate exposure to fully understand the dynamics in the chemical mixture during welding. The welders are exposed to significantly higher concentrations of ozone and nitrogen dioxide as shown by personal exposure measurements. This relationship is welding process-dependent.
E. Dahlen, Exponent Failure Analysis Associates, Menlo Park, CA.
Exponent was retained in a personal injury case involving an individual’s exposure to primary sludge at a wastewater treatment plant.
The individual, Mr. Jones, worked for a firm as a pipe fitter. In the process of relocating the blend tank at the wastewater treatment plant, Mr. Jones and his coworkers needed to open an 8-inch primary sludge line. Residual material drained from the pipe and was subsequently removed and the pipeline relocated. However, following this incident at the wastewater treatment plant, Mr. Jones became ill and claimed through his doctor to have been infected while working at the treatment plant.
Exponent’s analysis in this case centered around two issues. First, we were tasked with investigating the events that occurred up to and during the incident; and second, determining whether the exposure to the pipe contents could be linked to the claimed causative agent. We addressed the first issue by performing site inspections, reviewing plant drawings and depositions, quantifying the volume of primary sludge that could drain into the trench, and confirming that Mr. Jones in fact partook in the opening of the primary sludge line and that sludge drained into the trench. The second issue centered on whether the environmental conditions in the primary sludge line were conducive to the survival of Streptococcus agalactiae.
Mr. Jones was not able to convince the jury that a causal relation, in fact, existed between his exposure incident and his subsequent illness. There were no bacteriologic studies performed on Mr. Jones that could have identified the specific microorganism suspected of causing the illness and linking that organism to the contents of the primary sludge line. Furthermore, the claimed group B Streptococci are generally harmless and not common pathogens, and are unlikely to be found in wastewater.
K. Czarnocki, E. Czarnocka, T. Baum, Lublin University of Technology, Lublin, Poland.
WITHDRAWN
W. Lin, M. Chen, Chung Shan Medical University, Taichung, Taiwan, Republic of China.
WITHDRAWN
F. Rowell, L. Grieveson, B. Theaker, University of Sunderland, Sunderland, United Kingdom; D. Sykes, R. Cumming, University of Teesside, Middlesbrough, United Kingdom.
Development and use of a portable system comprising an air sampler coupled to an automated flow injection analysis device is described. This is able to monitor airborne concentrations of subtilisin-type enzymes in the workplace atmosphere on a continuous basis. Sampling is in two stages: first, capture of inhalable particles of 10 microns and less through a sampling head at a sampling volume of 600 L/min. In the second stage, the captured particles are deposited by impaction from the airstream onto the inner surface of a cyclone that is continuously washed with a jet of buffer solution. Deposited particles are then washed into a reservoir from which samples are taken every 5–6 min and injected automatically into a continuous flow injection analysis system. Proteolytic enzyme in the sample passes through a heated bioreactor. This contains a cellulose solid phase matrix on which is immobilized Texas Red-labelled gelatin as substrate. The passing enzyme partially digests the substrate releasing fluorophore that is detected downstream using a fluorimeter. The system is calibrated using enzyme standards and the intensity of the resulting peaks from the ex-air samples is converted to airborne concentrations using a pre-programmed PC. The system has a limit of detection of 4.8 ng/m3 and a dynamic range of 5–50 ng/m3. The within assay precision (RSD) is 6.3–9.6% over this range. The within batch precision is 20.3% at 20 ng/m3 and the corresponding between batch value is 19.5% . The system has been run for periods up to 8 hours in the laboratory and for up to 4 hours at two factory sites and the values obtained compared with time-averaged values obtained from a conventional high volume-type sampler and in-house analysis. Excellent correlation was observed (r2 = 0.996) and reasonable agreement of the concentrations.
T. Morris, Ohio BWC, Division of Safety and Hygiene, Cincinnati, OH.
Trace substances (TS) (intermediates, residual material, natural components, minor additives) are often ignored as a source of significant occupational exposures. Reasons for this include: it’s non-hazardous, there isn’t enough to produce an overexposure or toxicity, too much emphasis is placed on primary contaminants, it’s claimed as a trade secret, or its exposure potential has not been adequately evaluated. No universal definition of TS exists. Most components are reported based on the HazCom standard’s mixture reporting thresholds of 0.1% for carcinogens and 1% for noncarcinogens. Lower quantities must be reported if their release could result in an exposure >PEL/TLV or pose a health risk (rarely done). Trace levels of formaldehyde, cadmium, beryllium, and lead were found to produce significant employee exposures. In all but one case the material was not listed on an MSDS. Manually spraying a coating containing ~0.06% formaldehyde resulted in an exposure of 1.1 ppm (>AL and PEL). Cadmium exposures up to 7.2 ug/m3 (>PEL) or up to 4.8 ug/m3 (>AL) were recorded at two non-ferrous foundries where zinc containing 0.0004% Cd was used for alloying. TIG welding galvanized steel washers (<1% Pb) for 295-min produced a 12.2 ug/m3 Pb exposure; plasma cutting 304 stainless steel (<1% Pb) for 8-min resulted in a 75.1 ug/m3 exposure. A Be exposure of 0.5 ug/m3 (>NIC TLV) occurred while handling scrap and dross at a magnesium alloy recycling operation (0.007% Be in one alloy). All companies were unaware of the exposures and the associated regulatory requirements. TS can produce significant and unexpected exposures; their exposure assessment must include work practices and materials; they pose an assessment challenge and they can be an important point source affecting the type or location of a control method. These assessments demonstrate that TS cannot simply be ignored.
J. Hollander, R. Bjarke, Los Alamos National Laboratory, Los Alamos, NM.
This case study involves the machining and cleaning of welded beryllium. Welded parts were unable to meet stringent release requirements for beryllium surface contamination. Repeated, time-consuming cleaning was necessary. Some beryllium-containing weld splatter had remained on unmachined surfaces. Did abrasion of weld splatter contribute to elevated beryllium levels? With all splatter removed parts consistently met beryllium release standards. Repeated cleaning was avoided. Time was saved. Worker protection was enhanced. Other industrial hygiene practitioners can learn that surface quality, including finish, affects contamination levels. This can be significant at low levels such as required for beryllium release.
A. Poscik, Central Institute for Labour Protection-National Research Institute, Warszawa, Poland.
Aims: The aim of the presented research was to evaluate the method of selection and use of PPE in SMEs for prevention purpose. The second aim of the research was to create an efficient model of PPE management in enterprises.
Experimental procedures and discussion: In order to carry out this project it was necessary to analyze, in detail, PPE management in small and medium enterprises. The inquiry method was used to conduct the analysis. It was carried out on the representative group of 500 SMEs. The inquiry research proved that in many SMEs (about 65%) legal requirements of selection and application of PPE were not fulfilled. Serious differences in fulfilling particular requirements of legal regulations depending on the employment rate in the enterprises, economy branch were determined. Research showed that the proper management and appropriate selection of PPE is the major problem of the SMEs.
Application to the practice of industrial hygiene and occupational/enviromental health and safety: Conducted research enabled the National Labour Inspectorate to undertake an effective preventive action in order to improve the PPE management in SMEs. Results of the research were used to elaborate informational and training materials referring to the selection and the use of personal protective equipment addressed to SMEs of selected branches of business.
Conclusions: On the basis of the obtained research result, it was stated that about 65% of SMEs do not comply to legal requirements of PPE management. Furthermore, on the basis of the obtained data, the activities enabling the implementation of PPE effective management system in Polish SME were proposed.
Audience appeal: In many cases PPE is the easiest way to ensure health and safety in enterprises. This can lead to an overestimation of the efficiency of PPE and consequently to accidents at work.
Posted May 30, 2004