NIOSH oxides

Except for siUca and natural abrasives containing free siUca, the abrasive materials used today are classified by NIOSH as nuisance dust materials and have relatively high permissable dust levels (55). The OSHA TWA allowable total dust level for aluminum oxide, siUcon carbide, boron carbide, ceria, and other nuisance dusts is 10 mg/m. SiUca, in contrast, is quite toxic as a respkable dust for cristobaUte [14464-46-1] and tridymite [15468-32-3] the allowable TWA level drops to 0.05 mg/m and the TWA for quartz [14808-60-7] is set at 0.1 mg/m. Any abrasive that contains free siUca in excess of 1% should be treated as a potential health hazard if it is in the form of respkable dust. Dust masks are requked for those exposed to such materials (see Industrial hygene). 

When the data as a whole are reviewed for studies on humans exposed to ethylene oxide, no conclusion can be made that there is an increase in mortahty associated with those exposed to ethylene oxide. Two Swedish studies (247,248) indicated an increase in leukemia for workers exposed to multiple chemicals including ethylene oxide however, in a recent larger Swedish study (249) of workers exposed to only ethylene oxide, there was no association of any type of cancer increase for these workers. In a recent study sponsored by NIOSH, there was no significant increase in mortahty observed for cancer when all types are combined or for certain individual types of cancer, even for those people who worked the longest and were observed the longest. However, a statistically significant increase in mortahty from certain types of lymphoma was observed for male workers. This is contrary to the results observed for female workers. In addition, four other cohort studies of ethylene oxide-exposed workers have been pubhshed (250—253), but no unequivocal increase in the risk of cancer was observed. 

Information on occupational exposure to lead is obtained primarily from the National Occupational Exposure Survey (NOES) and industry surveys of workers. While occupational exposure is widespread, environmental monitoring data on levels of exposure in many occupations are not available. OSHA has established a permissible exposure limit (PEL) for lead of 50 pg/m3 for workplace air (OSHA 1991). NIOSH has estimated that more than 1 million American workers were occupationally exposed to inorganic lead in more than 100 occupations (NIOSH 1977a, 1978a). According to NOES, conducted by NIOSH between 1980 and 1983, an estimated 25,169 employees were exposed to tetraethyl lead (not used in gasoline since December 31, 1995) approximately 57,000 employees were exposed to various lead oxides mostly in non-ferrous foundries, lead smelters, and battery plants 3,902 employees were exposed to lead chloride and 576,579 employees were exposed to some other form of lead in the workplace in 1980 (NIOSH 1990). Workers who operate and maintain solid waste incinerators are also exposed to air lead levels as high as 2,500 pg/m3 (Malkin 1992). 

Use the NIOSH web site to determine and compare the PEL and the IDLH concentration of ethylene oxide and ethanol. 

Incineration or heating to decomposition releases toxic nitrogen oxides (Sittig, 1985) and cyanides (Lewis, 1990). Wet oxidation of acrylonitrile at 320 °C yielded formic and acetic acids (Randall and Knopp, 1980). Polymerizes readily in the absence of oxygen or on exposure to visible light (Windholz et al., 1983). If acrylonitrile is not inhibited with methylhydroquinone, it may polymerize spontaneously or when heated in the presence of alkali (NIOSH, 1997). 

Chemical/Physical. Slowly polymerizes with time into a viscous liquid (Windholz et al., 1983). Polymerization may be caused by elevated temperatures, oxidizers, or peroxides (NIOSH, 1997). 

Chemical/Physical. May react with strong mineral acids (e.g., hydrochloric) or oxidizers releasing isobutylene (NIOSH, 1997). 

Glaser ZR Special Occupational Hazard Review with Central Recommendations for the Use of Ethylene Oxide as a Sterilant in Medical Facilities. DHEW (NIOSH) Pub No 77-200. Washington, DC, US Gkjvemmental Printing Office, 1977... 

Sikov MR, Cannon WC, Carr DB Teratologic Assessment of Butylene Oxide, Styrene Oxide and Methyl Bromide. DHHS (NIOSH) Pub No 81-124. US Department of Health and Human Services, July 1981... 

Occupational Exposure to Oxides of Nitrogen (Nitrogen Dioxide and Nitric Oxide). DHEW (NIOSH) Pub No 76-149, pp 46-50, 75-76. Washington, DC, US Government Printing Office, 1976... 

Diborane in air may be analyzed by passing air through a PTFE filter and oxidizer-impregnated charcoal. It is oxidized to boron and desorbed with 3% H2O2. Boron is measured by plasma emission spectrometry or ICP emission spectrometry (NIOSH. 1984. Manual of Analytical Methods, 3rd ed. Cincinnati, OH National Institute for Occupational Safety and Health). Boron hydrides can be analyzed by FTIR techniques. 

The dissolution and measurement experiments start with attempts to dissolve a sample (300 yg or less) of a metal or metal compound species using the prescribed NIOSH procedure, followed by measurement using the NIOSH atomic absorption spectrometric (AAS) procedure. If 90 percent recovery of the metal is not achieved, the dissolution procedure is modified, or changed completely, to achieve 90 percent recovery. From previous studies, it is expected that the metal oxides, and selenium generally, would pose problems. The NIOSH-AAS procedures are to be evaluated also, especially when the dissolution matrix is changed. The AAS detection limits using standards are determined through the measurement of blanks. 

Analytical Methods. The official NIOSH recommended method for determining sulfur dioxide in air consists of drawing a known prefiltered volume of air through a bubbler containing hydrogen peroxide, thus oxidizing the sulfur dioxide to sulfuric acid. Isopropyl alcohol is then added to the contents in the bubbler and the pH of the sample is adjusted with dilute perchloric acid. The resultant solution is then titrated for sulfate with 0.005 M barium perchlorate, and Thorin is used as the indicator. 

Bis(tributyltin)oxide has been implicated in producing irritation of the upper respiratory tract and chest irritation, tightness, and pain in workers using a rubber material containing bis(tributyltin)oxide. Exposure conditions were not described. No changes were observed in pulmonary function tests (NIOSH 1976). 

NIOSH Methods 1300 and 1301 (NIOSH 1984) describe the determination of common ketones in air. The compounds evaluated in the study include acetone, methyl propyl ketone, methyl isobutyl ketone, methyl n-butyl ketone, diisobutyl ketone, cyclohexanone, ethyl butyl ketone, methyl amyl ketone, ethyl amyl ketone, mesityl oxide, and camphor [76-22-2], The analysis involves adsorption... 

Ethylene oxide is listed as a teratogen in the 1979 NIOSH subfile of RTECS (ref. 8le). 

La Borde, J.B. and C.A. Kimmel, "Teratogenicity of Ethylene Oxide Administered Intravenously to Mice," Toxicol Appl. Pharmacol. 56, 16-22 (1980). As cited in NIOSH ref. 76a. 

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