Review Of The U S Navy S Exposure Standard For Manufactured Vitreous Fibers

Manufactured vitreous fibers (MVF), also known as synthetic vitreous fibers, are considered to be less hazardous than asbestos to human health. They are used in many thermal- and acoustical-insulation applications as an asbestos substitute or as a filtration medium. The Navy uses MVF in shipboard and onshore applications. To protect Navy personnel from harmful exposures to MVF, the U.S. Navy Environmental Health Center (NEHC) developed occupational exposure standards. The documentation assists industrial hygienists, occupational medicine physicians, and other Navy health professionals in assessing and controlling the health hazards linked with exposure to MVF. In 1997, the National Research Council (NRC) was asked to conduct an independent review of the Navy's toxicological assessment of MVF and to evaluate the scientific validity of its exposure standard of 2 fibers per cubic centimeter of air (f/cm3). The NRC assigned the task to the Committee on Toxicology, which established the Subcommittee on Manufactured Vitreous Fibers, a multidisciplinary group of experts, to determine whether all relevant toxicological and epidemiological data were correctly considered in developing the exposure standard; and to examine the uncertainty, variability, and quality of data and the appropriateness of assumptions used in the derivation of the exposure standard. The subcommittee was also asked to identify deficiencies in the MVF database and, where appropriate, to make recommendations for future research and data development. Review of the U.S. Navy's exposure Standard for Manufactured Vitreous Fibers represents the subcommittee's final report. The committee had expanded its review when in January 1999, the Navy revised its Occupational Safety and Health Program Manual (CNO 1999), changing the occupational exposure limit for MVF to the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 1 f/cm3. The report features recommendations by the subcommittee as well as information gaps found throughout investigation. Overall, the subcommittee found that the Navy made a good start in assessing the health effects of MVF, but needed further research.

Manufactured vitreous fibers (MVF), also known as synthetic vitreous fibers, are considered to be less hazardous than asbestos to human health. They are used in many thermal- and acoustical-insulation applications as an asbestos substitute or as a filtration medium. The Navy uses MVF in shipboard and onshore applications. To protect Navy personnel from harmful exposures to MVF, the U.S. Navy Environmental Health Center (NEHC) developed occupational exposure standards. The documentation assists industrial hygienists, occupational medicine physicians, and other Navy health professionals in assessing and controlling the health hazards linked with exposure to MVF. In 1997, the National Research Council (NRC) was asked to conduct an independent review of the Navy's toxicological assessment of MVF and to evaluate the scientific validity of its exposure standard of 2 fibers per cubic centimeter of air (f/cm3). The NRC assigned the task to the Committee on Toxicology, which established the Subcommittee on Manufactured Vitreous Fibers, a multidisciplinary group of experts, to determine whether all relevant toxicological and epidemiological data were correctly considered in developing the exposure standard; and to examine the uncertainty, variability, and quality of data and the appropriateness of assumptions used in the derivation of the exposure standard. The subcommittee was also asked to identify deficiencies in the MVF database and, where appropriate, to make recommendations for future research and data development. Review of the U.S. Navy's exposure Standard for Manufactured Vitreous Fibers represents the subcommittee's final report. The committee had expanded its review when in January 1999, the Navy revised its Occupational Safety and Health Program Manual (CNO 1999), changing the occupational exposure limit for MVF to the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 1 f/cm3. The report features recommendations by the subcommittee as well as information gaps found throughout investigation. Overall, the subcommittee found that the Navy made a good start in assessing the health effects of MVF, but needed further research.

To protect space crews from contaminants in potable and hygiene water, NASA requested that the National Research Council (NRC) provide guidance on how to develop water exposure guidelines and subsequently review NASA's development of exposure guidelines for specific chemicals.

Extremely hazardous substances can be released accidentally as a result of chemical spills, industrial explosions, fires, or accidents involving railroad cars and trucks transporting EHSs. Workers and residents in communities surrounding industrial facilities where these substances are manufactured, used, or stored and in communities along the nation's railways and highways are potentially at risk of being exposed to airborne EHSs during accidental releases or intentional releases by terrorists. Pursuant to the Superfund Amendments and Reauthorization Act of 1986, the U.S. Environmental Protection Agency (EPA) has identified approximately 400 EHSs on the basis of acute lethality data in rodents. Acute Exposure Guideline Levels for Selected Airborne Chemicals, Volume 18 identifies, reviews, and interprets relevant toxicologic and other scientific data for selected AEGL documents for bromine chloride, carbonyl fluoride, selected halogen fluorides, and oxygen difluoride in order to develop acute exposure guideline levels (AEGLs) for these high-priority, acutely toxic chemicals. AEGLs represent threshold exposure limits (exposure levels below which adverse health effects are not likely to occur) for the general public and are applicable to emergency exposures ranging from 10 minutes (min) to 8 h. Three levels - AEGL-1, AEGL-2, and AEGL-3 - are developed for each of five exposure periods (10 min, 30 min, 1 h, 4 h, and 8 h) and are distinguished by varying degrees of severity of toxic effects. This report will inform planning, response, and prevention in the community, the workplace, transportation, the military, and the remediation of Superfund sites.

This book focuses on the application of carbon nanotubes and carbon nanofibers in traditional concretes based on Portland cement. Fundamental information is given related to the production technologies of carbon nanotubes and carbon nanofibers, as well as concretes and methods of incorporation. It also contains a section focusing on the possible negative effects of carbon nanotubes and carbon nanofibers on animals and humans. The book indicates benefits and possible problems related to the application of carbon nanotubes and carbon nanofibers in concrete. It is designed to be easy to access and digest for the reader, aiming to reach an audience, not only from academia, but also from the construction industry, materials producers, and contractors who might work with nanomaterials. Outlines the major properties and synthesis methods for carbon nanomaterials in concrete engineering; Explains the role of carbon nanotubes and nanofibers in creating high-performance concrete; Assesses the major challenges of integrating carbon nanomaterials into concrete manufacture on an industrial scale.

Acute Exposure Guideline Levels for Selected Airborne Chemicals, Volume 15 identifies, reviews, and interprets relevant toxicologic and other scientific data for ethyl mercaptan, methyl mercaptan, phenyl mercaptan, tert-octyl mercaptan, lewisite, methyl isothiocyanate, and selected monoisocyanates in order to develop acute exposure guideline levels (AEGLs) for these high-priority, acutely toxic chemicals. AEGLs represent threshold exposure limits (exposure levels below which adverse health effects are not likely to occur) for the general public and are applicable to emergency exposures ranging from 10 minutes (min) to 8 h. Three level--AEGL-1, AEGL-2, and AEGL-3--are developed for each of five exposure periods (10 min, 30 min, 1 h, 4 h, and 8 h) and are distinguished by varying degrees of severity of toxic effects. This report will inform planning, response, and prevention in the community, the workplace, transportation, the military, and the remediation of Superfund sites.

Beryllium is a lightweight metal that is used for its exceptional strength and high heat-absorbing capability. Beryllium and its alloys can be found in many important technologies in the defense and aeronautics industries, such as nuclear devices, satellite systems, radar systems, and aircraft bushings and bearings. Pulmonary disease associated with exposure to beryllium has been recognized and studied since the early 1940s, and an occupational guideline for limiting exposure to beryllium has been in place since 1949. Over the last few decades, much has been learned about chronic beryllium disease and factors that contribute to its occurrence in exposed people. Despite reduced workplace exposure, chronic beryllium disease continues to occur. Those developments have led to debates about the adequacy of the long-standing occupational exposure limit for protecting worker health. This book, requested by the U.S. Air Force to help to determine the steps necessary to protect its workforce from the effects of beryllium used in military aerospace applications, reviews the scientific literature on beryllium and outlines an exposure and disease management program for its protecting workers.

U.S. Navy personnel who work on submarines are in an enclosed and isolated environment for days or weeks at a time when at sea. To protect workers from potential adverse health effects due to those conditions, the U.S. Navy has established exposure guidance levels for a number of contaminants. In this latest report in a series, the Navy asked the National Research Council (NRC) to review, and develop when necessary, exposure guidance levels for 11 contaminants. The report recommends exposure levels for hydrogen that are lower than current Navy guidelines. For all other contaminants (except for two for which there are insufficient data), recommended levels are similar to or slightly higher than those proposed by the Navy. The report finds that, overall, there is very little exposure data available on the submarine environment and echoes recommendations from earlier NRC reports to expand exposure monitoring in submarines.