Occupational Exposure To Refractory Ceramic Fibers

The National Institute for Occupational Safety and Health (NIOSH) has reviewed data characterizing occupational exposure to airborne refractory ceramic fibers (RCFs) and information about potential health effects obtained from experimental and epidemiologic studies. From this review, NIOSH determined that occupational exposure to RCFs is associated with adverse respiratory effects as well as skin and eye irritation and may pose a carcinogenic risk based on the results of chronic animal inhalation studies. When the U.S. Congress passed the Occupational Safety and Health Act of 1970 (Public Law 91–596), it established the National Institute for Occupational Safety and Health (NIOSH). Through the Act, Congress charged NIOSH with recommending occupational safety and health standards and describing exposure limits that are safe for various periods of employment. These limits include but are not limited to the exposures at which no worker will suffer diminished health, functional capacity, or life expectancy as a result of his or her work experience. By means of criteria documents, NIOSH communicates these recommended standards to regulatory agencies (including the Occupational Safety and Health Administration [OSHA]), health professionals in academic institutions, industry, organized labor, public interest groups, and others in the occupational safety and health community. Criteria documents contain a critical review of the scientific and technical information about the prevalence of hazards, the existence of safety and health risks, and the adequacy of control methods. This criteria document is derived from reviews of information from human and animal studies of the toxicity of refractory ceramic fibers (RCFs) and is intended to describe the potential health effects of occupational exposure to airborne fibers of this material. RCFs are amorphous synthetic fibers produced by the melting and blowing or spinning of calcined kaolin clay or a combination of alumina, silica, and other oxides. RCFs belong to the class of synthetic vitreous fibers (SVFs)—materials that also include fibers of glass wool, rock wool, slag wool, and specialty glass. RCFs are used in commercial applications requiring lightweight, high-heat insulation (e.g., furnace and kiln insulation). Commercial production of RCFs began in the 1950s in the United States, and production increased dramatically in the 1970s. Domestic production of RCFs in 1997 totaled approximately 107.7 million lbs. Currently, total U.S. production has been estimated at 80 million lbs. per year, which constitutes 1% to 2% of SVFs produced worldwide. In the United States, approximately 31,500 workers have the potential for occupational exposure to RCFs during distribution, handling, installation, and removal. More than 800 of these workers are employed directly in the manufacturing of RCFs and RCF products. With increasing production of RCFs, concerns about exposures to airborne fibers prompted animal inhalation studies that have indicated an increased incidence of mesotheliomas in hamsters and lung cancer in rats following exposure to RCFs. Studies of workers who manufacture RCFs have shown a positive association between increased exposure to RCFs and the development of pleural plaques, skin and eye irritation, and respiratory symptoms and conditions (including dyspnea, wheezing, and chronic cough). In addition, current and former RCF production workers have shown decrements in pulmonary function.

Knowing the comprehensive history of a job or an employee's occupational exposure is important for determining worker exposures. Changes associated with jobs or job tasks can impact these exposures significantly. Often job descriptions are too general or are inadequate for determining a worker's true occupational exposure history. Collection of detailed task information may be helpful for categorizing worker exposures. This study used data collected annually by personal interview with individual employees between the years of 1988 and 1993 at three separate Refractory Ceramic Fiber (ROF) plants. Initially, over 350 Current Employee Questionnaire (CEO) interviews were evaluated and compiled on a computerized spreadsheet. Tasks were listed for each job title, year, and frequency reported from the interviews and cross-referenced to individual workers. To reduce inter-individual variability, only those interviews for which an individual worker was questioned for two or more years and did not change job titles were used. This reduced the number of CEO interviews to 69.

The Report on Carcinogens (RoC) is a congressionally mandated, science-based, public health document that identifies and discusses agents, substances, mixtures, or exposure circumstances (hereinafter referred to as "substances") that may pose a hazard to human health by virtue of their carcinogenicity. For each listed substance, the report contains a substance profile which provides information on (1) the listing status, (2) cancer studies in humans and animals, (3) studies of genotoxicity (ability to damage genes) and biologic mechanisms, (4) the potential for human exposure to these substances, and (5) Federalregulations to limit exposures. Eight substances have been added to this 12th ed. of the report, which now includes 240 listings. The industrial chemical formaldehyde and a botanical known as aristolochic acids are listed as known human carcinogens. Six other substances captafol, cobalt-tungsten carbide (in powder or hard metal form), certain inhalable glass wool fibers, o-nitrotoluene, riddelliine, and styrene are added as substances that are reasonably anticipated to be human carcinogens. Figures. This is a print on demand report.

Providing a concise, yet comprehensive, reference on all aspectsof industrial exposures and toxicants; this book aidstoxicologists, industrial hygienists, and occupational physiciansto investigate workplace health problems. • Updates and expands coverage with new chapterscovering regulatory toxicology, toxicity testing, physical hazards,high production volume (HPV) chemicals, and workplace druguse • Includes information on occupational and environmentalsources of exposure, mammalian toxicology, industrial hygiene,medical management and ecotoxicology • Retains a succinct chapter format that has become thehallmark for the previous editions • Distils a vast amount of information into one resourcefor both academics and professionals

This volume is part of the Ceramic Engineering and Science Proceeding (CESP) series. This series contains a collection of papers dealing with issues in both traditional ceramics (i.e., glass, whitewares, refractories, and porcelain enamel) and advanced ceramics. Topics covered in the area of advanced ceramic include bioceramics, nanomaterials, composites, solid oxide fuel cells, mechanical properties and structural design, advanced ceramic coatings, ceramic armor, porous ceramics, and more.

This revised and updated new edition of a successful book is a multidisciplinary, comprehensive guide to occupational factors of malignant diseases. Building on the first edition, new research discoveries and their consequences in our understanding on carcinogenic mechanisms, diagnosis and attribution of occupational cancers are discussed. Examples of such discoveries are germline and acquired mutations of BAP1 in malignant mesothelioma, which have led to changes in diagnostic criteria, and carcinogen-specific genetic and epigenetic alterations in lung cancer. There are several new chapters, including gastrointestinal cancers, epidemiology of lung cancer, cancer of thyroid, and the role of primary health care in occupational cancer control. Occupational Cancers is aimed at experienced and trainee oncologists, pathologists, clinicians in occupational health, and pulmonologists, as well as epidemiologists, clinical researchers, lawyers and public health officials.