Worker Exposure to Volatile Organic Compounds in the Vehicle Repair Industry

Abstract

This study evaluated exposures among vehicle repair technicians to hexane, acetone, toluene, and total volatile organic compounds (VOCs). On randomly selected workdays, we observed a characteristic pattern of solvent use among 36 technicians employed in 10 repair shops, each of which used an aerosol solvent product. We obtained quantitative exposure measurements from a subset of nine technicians (employed in three of these shops) who used an aerosol product containing hexane (25-35%), acetone (45-55%), and toluene (5-10%). The time-weighted average (TWA) exposure concentration for task-length breathing zone (BZ) samples (n = 23) was 36 mg/m(3) for hexane, 50 mg/m(3) for acetone, and 10 mg/m(3) for toluene. The TWA area concentrations (n = 49) obtained contemporaneously with BZ samples ranged from 25% to 35% of the BZ concentrations. The solvent emission rate (grams emitted/task time) was correlated with the total VOC exposure concentration (R(2) = 0.45). The proportions of VOCs in the BZ samples were highly correlated (r = 0.89 to 0.95) and were similar to those of the bulk product. Continuous exposure measurements for total VOCs (n = 1238) during 26 tasks produced a mean BZ VOC "pulse" of 394 mg/m(3) within 1 min following initiation of solvent spraying. The geometric mean air speed was 5.2 meters/min in the work areas (n = 870) and was associated with 0.8 air changes per minute in the BZ. The findings suggest that vehicle repair technicians who use aerosol solvent products experience episodic, inhalation exposures to the VOCs contained in these products, and the proportions of VOCs in the breathing zone are similar to those of the bulk product. Because acetone appears to amplify the severity and duration of the neurotoxic effects of n-hexane, products formulated with both hexane and acetone should be avoided. Further evaluation of exposures to VOCs is needed in this industry, along with information on effective alternatives to aerosol solvent products.

Evaluating Indoor Exposure Modeling Alternatives for LCA: A Case Study in the Vehicle Repair Industry

“…Over 7 trials, 13.8%±2.3% of the mass sprayed was retained on the brake, 27.5%±15.9 % was lost as drip-off, and overspray to the surrounding air amounted to 58.7 %±16.1% (see Methods, Experimental Data 2, and Figure S2). [5] reported that, for a 30 s spraying period, the average amount of brake cleaner emitted as VOCs was 116 g. This corresponds to a constant emission rate of 3.87 g/s. The emission rate G can be (Table 1).…”

“…Wilson et al [5] employed qualitative and quantitative methods to characterize VOC exposure among vehicle repair technicians during typical repair tasks. They observed nine technicians in three shops (Sites A-C, Tables S1-S3) that used a commercially available "aerosol" product (Product #1) and participated in quantitative exposure measurements.…”

“…Real-time breathing-zone concentrations peaked at 394 mg/m 3 at 60-75 seconds after the initiation of spraying [5]. Immediately after spraying stops, we see a significant drop in concentration during the first 45 s, followed by a slower decline to background concentration levels [4].…”

Exposure Evaluation for Benzene, Lead and Noise in Vehicle and Equipment Repair Shops

“…They are also subject to exposure to dusts and particulates, in addition to physical hazards such as noise from use of impact wrenches and grinders (Bejan et al 2011). Aerosol spray cans are the most widely used delivery system for many solvents in mechanic shops (Wilson et al 2007). The constituents in most non-chlorinated aerosol degreasing solvents include volatile organic compounds (VOCs).…”

“…The constituents in most non-chlorinated aerosol degreasing solvents include volatile organic compounds (VOCs). VOCs, as a source of exposure, present an episodic inhalation hazard to the product user (Wilson et al 2007). While several aerosol solvents are manufactured and labeled for a specific vehicle component or system, the products contain many of the same petroleum-derived compounds and are often used interchangeably in repair shops.…”