Asbestos exposure limits

Country Asbestos exposure limits Fiber type Exposure limits for SMF and nuisance dust... 

Asbestos exposure limits and measurement of airborne dust concentrations... 

Another aspect of OELs is that they tend to decrease gradually over time as they are revised. The half-life1 of OELs displayed in Table 9.2 is an example of that. This has also been shown in other several studies, e.g. Hansson (1998) which includes a review of the Swedish OELs from 1969 to 1992. Greenberg (2004) made a review of the documentation of British asbestos exposure limits from 1898 to 2000 and Markowitz and Rosner (1995) reviewed the TLV for silica from 1935 to 1990. Both these studies show that the OELs are lowered as more information on adverse effects becomes available and the protection of worker s health is given higher priority. This aspect points at the influence of each organisation s time-frame for the update procedures. 

Several strict federal and state environmental and safety laws are in place to limit asbestos exposure. These laws require employers to provide protection and training to the workers who may disturb asbestos. OSHA has also established a permissible asbestos exposure limit that places tight restrictions on the acceptable levels of airborne asbestos fibers. 

EH10 Asbestos - Exposure limits and measurements of airborne dust concentrations (1988) EH 25 Cotton dust sampling (1980)... 

Asbestos-exposure limits and measurement of airborne dust concentrations Arsine - health and safety precautions Stibine - health and safety precautions Bery 11 ium — health and safety precautions Level of trainirtg for technicians making noise surveys Threshold limit values (superseded by EH 40)... 

Asbestos exposure Limits and measurement of airborne dust concentrations. Environmental Hygiene Guidance Note EH10 (seventh edition), HSE Books, 2001 ISBN 07176 2129 4... 

The toxicological problems associated with asbestos have been widely pubHshed and asbestos has been banned from most uses by the EPA. However, modem diaphragm cell chlorine plants have not had difficulty meeting the required exposure limits for asbestos fibers, and, as of 1990, the chlorine industry had an exemption allowing the continued use of asbestos as a diaphragm material. 

PPS dust should be treated as a nuisance particulate. The OSHA permissible exposure limit for respirable dust is 5 mg/m for dust containing no asbestos and less than 1% siUca. The principal decomposition products released during mol ding of PPS and their permissible exposure limits are given in Table 10. Sulfur dioxide and carbonyl sulfide are the most significant off-gases for production of mucous membrane irritation. 

In accordance with demonstrated differences between the various asbestos fiber types, the workplace regulation in many countries specifies different exposure limits for chrysotile and the amphiboles (45). Moreover, to alleviate estabHshed, or apprehended, risk from substitute fibers, the regulation often specifies maximum exposure limits for synthetic fibers (46) values of exposure limits adopted in leading industrial countries are coUected in Table 8. 

Table 8. Exposure Limits for Asbestos Fibers, Synthetic Mineral Fibers (SMF) and Nuisance Dust in the Workplace ...

Work with asbestos insulating board (superseded by EH 71j Ozone health hazards and precautionary measures Occupational exposure limits (annual)... 

Amperometric cells, sensors using, 22 271 Amperometric measurements, 14 612 Amphetamine, 3 89-90 Amphibole asbestos, 1 803 3 288 crystal structure, 3 297-298 exposure limits, 3 316 fiber morphology, 3 294-295 silicate backbone, 3 296 Amphibole potassium fluorrichterite, glass- ceramics based on, 12 637 Amphiphile-oil-water-electrolyte phase diagram, 16 427-428 Amphiphile-oil-water phase diagrams,... 

Two main provisions of the regulations fall into the federal category of Permissible Exposure Limits (PELs) to airbome asbestos fibers. They are ... 

Only in the case of ultra high speed burnishing was the OSHA PEL exceeded. However, this was due to the generation of nonasbestos particles during the burnishing process and therefore do not reflect actual asbestos exposure. This example underscores the limitations of PCM in interpreting workplace exposure. 

Begin R, Boileau R, Peloquin S. 1987a. Asbestos exposure, cigarette smoking, and airflow limitation in long-term Canadian chrysotile miners and millers. Am J Ind Med 11 55-66. 

Begin R, Cantin A, Sebastien P. 1990. Chrysotile asbestos exposures can produce an alveolitis with limited fibrosing activity in a subset of high fibre retainer sheep. Eur Respir J 3 81-90. 

Lung Cancer and Mesothelioma Based on an analysis of data from epidemiologic studies of workers who were exposed to asbestos before modem occupational exposure limits were established, EPA (1986) calculated by extrapolation that lifetime exposure to asbestos air concentrations of 0.0001 fiber/mL could result in up to 2 to 4 excess cancer deaths (lung cancer or mesothelioma) per 100,000 people. This air concentration is within reported ranges of ambient air levels (0.00001 to 0.0001 liber/mL). The EPA analysis has been extensively discussed and reviewed in the scientifrc literature (Camus et al. 1998 ... 

Montana, vermiculite (Atkinson et al. 1982 Moatamed et al. 1986 McDonald et al. 1988). It is plausible that the lack of increased prevalences of diseases associated with asbestos exposure in these woikers is primarily due to the very low levels of asbestiform amphibole minerals in these vermiculite deposits (Atkinson et al. 1982 Moatamed et al. 1986 Ross et al. 1993). In addition, such factors as lower levels of airborne fiber concentrations at the worksites, small numbers of subjects in the studies, and limitations in study design and exposure data may have contributed to this lack of evidence. 

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