Exposure workplace

Sources of human exposure to formaldehyde are engine exhaust, tobacco smoke, natural gas, fossil fuels, waste incineration, and oil refineries (129). It is found as a natural component in fmits, vegetables, meats, and fish and is a normal body metaboHte (130,131). FaciUties that manufacture or consume formaldehyde must control workers exposure in accordance with the following workplace exposure limits in ppm action level, 0.5 TWA, 0.75 STEL, 2 (132). In other environments such as residences, offices, and schools, levels may reach 0.1 ppm HCHO due to use of particle board and urea—formaldehyde foam insulation in constmction. 

Health and Safety Factors. Malononitrile is usually available as a soHdifted melt in plastic-Hned dmms. Remelting has to be done carefully because spontaneous decomposition can occur at elevated temperatures, particularly above 100°C, in the presence of impurities such as alkaHes, ammonium, and 2inc salts. Melting should be carried out by means of a water bath and only shordy before use. Occupational exposure to malononitrile mainly occurs by inhalation of vapors and absorption through the skin. Malononitrile has a recommended workplace exposure limit of 8 mg/m, an LD q (oral, rats) of 13.9 mg/kg, and is classified as slight irritant (skin irritation, rabbits). Transport classification RID/ADR 61, IMDG-Code 6.1, lATA/ICAO 6.1. 

Other Accelerators. Amine isophthalate and thiazolidine thione, which are used as alternatives to thioureas for cross-linking polychloroprene (Neoprene) and other chlorine-containing polymers, are also used as accelerators. A few free amines are used as accelerators of sulfur vulcanization these have high molecular weight to minimize volatility and workplace exposure. Several amines and amine salts are used to speed up the dimercapto thiadiazole cure of chlorinated polyethylene and polyacrylates. Phosphonium salts are used as accelerators for the bisphenol cure of fluorocarbon mbbers. 

Toxicity Data on Af- Vinyl-2-Pyrrolidinone. Results of a chronic inhalation study in rats warrant a review of industrial hygiene practices to assure that VP vapor concentrations are maintained at a safe level. One of the manufacturers, ISP, recommends that an appropriate workplace exposure limit be set at 0.1 ppm (vapor) (9). Additionally, normal hygienic practices and precautions are recommended, such as prompt removal from skin and avoidance of ingestion. In case of accidental eye contact, immediately flush with water for at least 15 minutes and seek medical attention. Refer to the manufacturers Material Safety Data Sheets for more detailed information. Table 3 provides some toxicity data. 

The relationship between workplace exposure to airborne asbestos fibers and respiratory diseases is one of the most widely studied subjects of modern epidemiology (37—39). Asbestos-related health concerns were first raised at the beginning of the century in the UK and the latter appears to have been the first country to regulate the asbestos-user industry (40). However, at that time, infectious respiratory diseases were a much greater concern than those arising from poor industrial hygiene practices. 

Beryllium, beryllium-containing aUoys, and beryUium oxide ceramic in soHd or massive form present no hazard whatsoever (31). SoHd shapes may be safely handled with bare hands (32) however, care must be taken in the fabrication and processing of beryUium products to avoid inhalation of airborne beryUium particulate matter such as dusts, mists, or fumes in excess of the prescribed workplace exposure limits. Inhalation of fine airborne beryUium may cause chronic beryUium disease, a serious lung disease in certain sensitive individuals. However, the vast majority of people, perhaps as many as 99%, do not react to beryUium exposure at any level (33). The biomedical and environmental aspects of beryUium have been summarized (34). 

Safe Exposure Levels. The U.S. Occupational Safety and Health Administration (OSHA) has adopted workplace exposure limits designed to keep airborne concentrations weU below the levels known to cause health problems (35) including ( ) daUy time-weighted average (TWA) exposure over an eight-hour day is not to exceed beryUium concentrations of 2 lg/m of air and (2) short-term exposure should not exceed beryUium concentrations of 25... 

BTX processing has come under steadily increasing pressure to reduce emissions and workplace exposures (see Industrial hygiene). Reductions in the permissible levels of both benzene and total aromatics (BTX) in gasoline have been legislated. Whereas all BTX components ate to be controUed, the main focus is on benzene because it is considerably mote toxic than the others and is classified as a known carcinogen (42). 

Workplace exposure limits for benzene have been regulated to levels as low as 0.5 ppm (43). Industrial emissions affecting the pubHc ate now low enough that the EPA considers that a greater hazard exists from mosdy indoor sources such as smoking, automobile exhausts, and consumer products (44). 

Cobalt compounds can be classified as relatively nontoxic (33). There have been few health problems associated with workplace exposure to cobalt. The primary workplace problems from cobalt exposure are fibrosis, also known as hard metal disease (34,35), asthma, and dermatitis (36). Finely powdered cobalt can cause siUcosis. There is Htfle evidence to suggest that cobalt is a carcinogen in animals and no epidemiological evidence of carcinogenesis in humans. The LD q (rat) for cobalt powder is 1500 mg/kg. The oral LD q (rat) for cobalt(II) acetate, chloride, nitrate, oxide, and sulfate are 194, 133, 198, 1700, 5000, and 279 mg/kg, respectively the intraperitoneal LD q (rat) for cobalt(III) oxide is 5000 mg/kg (37). 

Do workplace exposures comply with occupational exposure limits or applicable regulatory limits, if they are more stringent If no, explain. 

In recent years, the use of solvent-borne adhesives has been seriously restricted. Solvents are, in general, volatile, flammable and toxic. Further, solvent may react with other airborne contaminants contributing to smog formation and workplace exposure. These arguments have limited the use of solvent-bome adhesives by different national and European regulations. Although solvent recovery systems and afterburners can be effectively attached to ventilation equipment, many factories are switching to the use of water-borne rubber adhesives, hot melts or 100% solids reactive systems, often at the expense of product performance or labour efficiency. 

Control of individual workplace exposures in a manner that minimizes adverse health effects [3]... 

The advantage of using capture efficiency is that it is possible to calculate how much of the contaminant is released into a workspace (if the source rate is known) and thus to judge if the exhaust will reduce workplace exposures to acceptable levels. Its disadvantage is that it is rather difficult to measure and, moreover, it is usually impossible to calculate source generation rate. 

Compliance with regulations and internal standards. These requirements usually cover emissions tonnage or concentrations, workplace exposure levels and progress in correcting noncompliances. 

Human health effects of operations. This requires assessment of such things as workplace exposures effects of exposure to air toxics, contaminated drinking water and soil and exposures during product use, misuse, and disposal. 

In contrast, three European studies have found slight but statistically significant increases in cancer in workers exposed to trichloroethylene. A survey of Finnish workers exposed to primarily trichloroethylene found an association of limited statistical significance between exposure and incidence of stomach, liver, prostate, and lymphohematopoietic cancers (Antilla et al. 1995). However, the study did not reliably separate the effects of individual solvents, so attributing these cancers to trichloroethylene exposure alone was not possible. A significant association between workplace exposure to trichloroethylene and kidney cancer was found in a retrospective cohort study of German cardboard factory workers (Henschler et al. 1995). The... 

ACGIH maintains annual editions of the TLVs and BEIs which are used worldwide as a guide for evaluation and control of workplace exposures to chemical substances and physical agents. Threshold Limit Value (TLV ) occupational exposure guidelines are recommended for more than 700 chemical substances and physical agents. There are more than 50 Biological Exposure Indices (BEIs ) that cover more than 80 chemical substances. 

OSHA (Occupational Safety and Health Administration). 1997. Workplace exposure levels for aniline. Printout received from Paul Tobin, U.S. Environmental Protection Agency. Jan. 13. 

Identification determination of the presence or possibility of workplace exposures. 

Control application of appropriate technology to reduce workplace exposures to acceptable levels. 

After potential health hazards are identified and evaluated, the appropriate control techniques must be developed and installed. This requires the application of appropriate technology for reducing workplace exposures. 

The Perbellini PBPK model for -hexane is the only validated model for this chemical identified in the literature. The Fisher model was intended for risk assessment to predict which of 19 volatile organic chemicals may be present in milk at a high enough level after workplace exposure to raise health concerns for a nursing infant. 

Cases of -hexane toxicity in humans have occurred as the result of workplace exposure and solvent abuse (Spencer et al. 1980). Some of these cases of peripheral neuropathy have occurred in teenagers (particularly with solvent abuse) however, none of the clinical reports indicate differences in physical signs or functional tests between this group and adults (Altenkirch et al. 1977 Yamamura et al. 1969). While no reports of -hexane toxicity in young children were located, it is probable that similar toxicity would occur if exposure was comparable to that in affected adults. Specific information is not available on whether children are more susceptible than adults to the effects of -hexane. 

Aw C. 1987. Workplace exposures causing male infertility. Occup Health (Lond) 39(10) 326-328. 

At the workplace, exposure to phenol can occur from breathing contaminated air. However, skin contact with phenol during its manufacture and use is considered the major route of exposure in the workplace. It has been estimated that about 584,000 people in the United States are exposed... 

A number of effects from breathing phenol in air have been reported in humans. Short-term effects reported include respiratory irritation, headaches, and burning eyes. Chronic effects of high exposures included weakness, muscle pain, anorexia, weight loss, and fatigue effects of chronic low-level exposures included increases in respiratory cancer, heart disease, and effects on the immune system. Virtually all of the workplace exposures associated with these effects involved exposures to other chemicals, thus it is difficult to determine whether these are solely due to phenol, or are the result of mixed, multiple, or other chemical exposures. 

RosenmanKD. 1984. Cardiovascular disease and workplace exposures. Arch Environ Health 39 218-224. 

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