Worker Exposures

Polypropylene. Polypropylene (PP) is used ia packagiag appHcations as films and ia rigid containers. Battery cases could be considered another packagiag appHcation. Dead batteries are often collected at the poiat of sale of new batteries. In the U.S., some states have laws mandating this. Lead, acid, and plastics, particularly PP from battery casiags is recovered and recycled (3). Care must be taken to limit worker exposure to lead duting this process (44). PP is also recovered from bale wrap and other PP fabrics used for wrappiag ia the textile iadustry and from other containers (45). 

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. 

Inhalation is the chief route of worker exposure. Comparative data from acute or subchronic inhalation exposures with rats (98) indicate that nitromethane and nitroethane are the least toxic of the nitroparaffins by this route and do not induce methemoglobin formation. The nitropropanes are less well tolerated 2-nitropropane is more toxic than 1-nitropropane and is more likely to cause methemoglobinemia. 

Health and Safety. Both N-methylpyrrohdinone and dibasic esters have very low vapor pressure which limits worker exposure to vapors. Manufacturers recommend that the same safety precautions be taken as with other organic solvents. Ha2ardous location requirements must be considered if the formula is flammable. Ventilation that reduces vapors to manufacturer s recommended exposure levels should be used. 

AH of the toxicity data on MDA have been collected using either 4,4 -MDA or the corresponding hydrochloride salt. The information discussed in this section can also be used for commercial products containing MDA or PMDA. Because MDA is a potentially ha2ardous chemical, worker exposure should be kept to a minimum. For complete health and safety information on MDA consult references 46 and 56—59. 

The use of nuclear power has been a topic of debate for many years. Nuclear fuel represents a resource for generating energy weU into the future, whereas economically recoverable fossil fuel reserves may become depleted. Worker exposure, injuries, and fataHties in nuclear fuel mining are reportedly far less compared to those associated with recovery and handling of fossil fuels. Potential hazards associated with transporting and storing radioactive wastes do exist, however. 

Environmental Issues. The mbber industry has responded to concerns about the environment by developing new product forms for accelerators and other chemicals which improve industrial hygiene and minimize worker exposure to these materials by eliminating dust exposure and improving handling ease. Another important benefit for newer product forms is better, more consistent quaHty mbber products resulting from improved factory practices. 

Vinyhdene chloride is hepatotoxic, but does not appear to be a carcinogen (13—18). Pharmacokinetic studies indicate that the behavior of vinyl chloride and vinyhdene chloride in rats and mice is substantially different (19). No unusual health problems have been observed in workers exposed to vinyhdene chloride monomer over varying periods (20). Because vinyhdene chloride degrades rapidly in the atmosphere, air pollution is not likely to be a problem (21). Worker exposure is the main concern. Sampling techniques for monitoring worker exposure to vinyhdene chloride vapor are being developed (22). 

Ethylene dibromide is a suspected human carcinogen and worker exposure by all routes should be carefiiUy controUed to levels as low as reasonably achievable (67). Ethylene dibromide causes severe blistering of the skin if contact is prolonged. Eye contact with the Hquid will cause pain, irritation, and temporary impairment of vision. Recommended safety equipment includes safety goggles, a NIOSH approved canister-type gas mask for organic vapors, neoprene gloves, and neoprene overshoes. In case of contact with ethylene dibromide, contaminated clothing and shoes should be removed and eyes or skin washed with plenty of water for at least 15 minutes. Contaminated clothes should be washed before reuse and contaminated shoes should be discarded. 

Toxicity. 1,1-Dichloroethane, like all volatile chlorinated solvents, has an anesthetic effect and depresses the central nervous system at high vapor concentrations. The 1991 American Conference of Governmental Industrial Hygienists (ACGIH) recommends a time-weighted average (TWA) solvent vapor concentration of 200 ppm and a permissible short term exposure level (STEL) of 250 ppm for worker exposure. The oral LD q of... 

Dichloroethylene is toxic by inhalation and ingestion and can be absorbed by the skin. It has a TLV of 200 ppm (10). The odor does not provide adequate warning of dangerously high vapor concentrations. Thorough ventilation is essential whenever the solvent is used for both worker exposure and flammabihty concerns. Symptoms of exposure include narcosis, dizziness, and drowsiness. Currently no data are available on the chronic effects of exposure to low vapor concentrations over extended periods of time. 

For worker exposure to trichloroethylene vapor, OSHA set a maximum eight-hour time-weighted average (TWA) concentration of 100 ppm. This severely restricted certain appHcations, and many organizations converted to other chlorinated solvents. As a result, U.S. production of trichloroethylene declined about 70% from a peak in 1970 (Table 2). In 1989, OSHA lowered the permissible exposure limit (PEL) from 100 ppm eight-hour TWA to 50 ppm eight-hour TWA (33). This added further pressure for some users to consider changing to alternative solvents. 

The exposure level estabUshed by NIOSH for the workplace is 0.1 mg/m (42). ACGIH has recommended a TLV of 0.05 mg/m for cobalt. At the ACGIH worker exposure levels it has been suggested that occupational health problems would not occur (41). 

Health and Safety. Eree phenols may be present in phenoHc novolacs and resoles. Phenol [108-95-2] is poisonous and caustic, irritating the skin and mucous membranes. Eormaldehyde and ammonia [7764-41-7] are often emitted during the cure of novolacs and must be properly vented. Eormaldehyde is Hsted as a human carcinogen worker exposure and emissions are controUed by OSHA and the EPA. 

After polymerization, excess monomer is stripped and recycled. The residual monomer content of the stripped emulsion does not represent an acute hazard. Worker exposure to monomer is monitored, and sources of exposure identified and corrected. 

Are there any exposures to hazardous agents that may endanger worker health or cause worker exposure concerns If yes, explain. 

Exposures to carcinogens must be kept to a minimum. Workers exposed to A1 carcinogens without a TLV should be properly equipped to eliminate to the fullest extent possible all exposure to the carcinogen. For A1 carcinogens with a TLV and for A2 carcinogens, worker exposure by all routes should be carefully controlled to levels as low as reasonably achievable (ALARA) below the TLV. 

Solids handling frequently has the potential for dusting, which can lead to potential health and explosion hazards. Handling solids in the form of larger particle size granules or pellets rather than a fine powder reduces the potential for worker exposure. Worker exposure hazards are reduced by formulating dyes as liquids or wet pastes rather than dry solids or powders (Burch, 1986). 

Precludes worker exposure by Substitution safety Requires time to implement... 

Personal protective equipment Respiratory protection Gives workers direct access to worksite Increases worker exposure to hazard... 

For other CERCLA sites the proeess ean be very different from the typieal DOE site. The proeess may start with various phases of site assessments. The intermediate step may be a pilot study, followed by a pilot plant operation, or possibly a removal aetion or other alternative. The final steps may vary widely. However, just as in DOE sites, the appropriate rule or requirement depends on the site-speeifie faeility or operation, the assoeiated hazards, and the potential for worker exposure to the hazards. For the Army Corps of Engineers eleanup or oversight, the rules will most likely be even more stringent than for OSHA or DOE. 

Any site-related activities such as bench-scale laboratory and R D activities should comply with the OSHA Laboratory Standard (29 CER 1910.1450). R D activities involving pilot- or full-scale field operations should comply with HAZWOPER when there is reasonable possibility for worker exposure to hazardous wastes or substances or emergency response. 

An exposure assessment uses air-monitoring data to determine possible worker exposures. This data is used to identify eontrols for worker proteetion and provide monitoring results to physieians for proper medieal assessment, treatment, and follow-up eare. 

Consider some alternatives. We should eonsider using eontrol aeeess zones (CAZ) to limit worker exposure to zones where slip, trip, and fall hazards exist. By limiting worker exposure we should be limiting aeei-dent oeeurrenees. If equipment is a temporary problem, we should eonsider leasing or rental. If labor is a problem, we might eonsider utilization of temporary employment ageneies. 

Critical to hazard characterization is the identification of hazards and the assessment of possible worker exposure. This can be accomplished in a variety of ways. As described before, one commonly used technique is a JHA with project teams that include the worker. The information collected is used by the SSHO and the radiation control officer to develop an appropriate hazard control and protection strategy. 

Provide ongoing assurance that access and hazard controls limit worker exposure... 

A medical surveillance program is designed to protect the workers health. Given the limitations of industrial hygiene monitoring data and the many hazards involved in hazardous waste activities, medical surveillance data may provide the only indication that worker exposure to toxic substances has occurred. 

The levels of PPE discussed provide controls of the hazardous substance based on the degree of worker exposure. As we have discussed before, PPE is only acceptable as a hazard control measure in the following situations ... 

FIGURE 9-20. This worker is wearing respiratory protection along with a lapel badge which can be used to determine TWA worker exposures. Photo Courtesy 3M... 

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