Abstract:

Objective To qualitatively analyze the volatile organic compounds (VOCs) present in paint materials using headspace gas chromatography-mass spectrometry (HS-GC-MS) and to identify occupational hazard factors associated with spray-painting operations in automobile 4S shops.

Methods From September to October 2021, paint samples used in spray-painting operations were collected from 32 automobile 4S shops across four districts of Shanghai (Yangpu, Xuhui, Putuo, and Songjiang). Samples were introduced via an automated headspace sampler, separated by gas chromatography, and detected by mass spectrometry. Air samples were also collected from spray-painting workplaces to determine airborne VOC concentrations.

Results A total of 65 paint samples were collected, including 33 clear-coat samples and 32 colored-paint samples. Overall, 258 VOCs were identified from these 65 samples, with a total of 1 462 detections. The relative contents of esters and ketones were significantly higher in clear-coat samples than in colored-paint samples (P < 0.05). The ten most frequently detected VOCs among the 65 samples were acetone (62 times), butyl acetate (61), n-butanol (60), xylene (57), ethylbenzene (51), trimethylbenzene (48), ethyltoluene (42), 2-methyl-2-propanol (35), methyl methacrylate (33), and n-propylbenzene (31). The compounds with the highest average relative contents were 2-butoxyethanol (0.460), 2-butanol (0.231), and isopropanol (0.138). Among the identified VOCs, 34 substances had occupational exposure limits specified in GBZ 2.1—2019. The airborne concentrations of these occupational hazards at all 36 spray-painting workstations were lower than the occupational exposure limits, while 22 workstations showed no detectable levels of occupational hazards.

Conclusions A wide variety of VOCs were present in spray-painting operations in automobile 4S shops in Shanghai. Qualitative analysis is therefore necessary to assist in identifying the VOCs to which spray-painting workers may be exposed, thereby improving the accuracy of hazard identification and providing a scientific basis for monitoring and controlling occupational hazards in these workplaces.