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INDUSTRIAL ORGANIC SOLVENTS
Published in Nicholas P. Cheremisinoff, Industrial Solvents Handbook, Revised And Expanded, 2003
Solvent-based coatings can be classified as conventional low-solids and high-solids ( 60% solids) coatings. Glycol ethers and acetates act as active solvents to dissolve the film-forming resins and to suspend pigments and additives. Conventional low-solids coatings contain alkyd, epoxy, nitrocellulose, polyester, and polyurethane-type resins and find use in coil coating, metal and wood furniture, automotive coatings, and machinery finishes. These coatings can be classified as thermoplastic or thermoset. Evaporation of the solvents yields the thermoplastic film while the thermoset coating is cured by a chemical cross-linking reaction or by air oxidation in a high temperature oven. Selection of the proper glycol ether depends on how the coating is cured. Ambient cured coatings often utilize EB, PM, and DPM glycol ethers and propylene glycol methyl ether acetate (PMA). For thermally cured coatings the above mentioned glycol ethers as well as blends can be used. In high temperature coil coating processes the diethylene glycol n-butyl ether and dipropylene glycol methyl ether acetate (DPMA) are often used as tailing solvents (these solvents prevent pinholes and other film defects during the last stages of cure).
Proposal for a neurotoxic classification for chemicals at work
Published in Archives of Environmental & Occupational Health, 2021
Shiraz Dib, Thi-Hai-Yen Nguyen, Julie Bodin, Mélanie Bertin, Alexis Descatha, Yves Roquelaure, Nathalie Bonvallot
Glycol ethers are a family of more than 80 chemicals consisting of oxygenated solvents largely used in industrial processes and consumer products (paints, varnishes, detergents, etc.). The most highly used glycol ethers in Europe are ethylene glycol butyl ether (EGBE) and propylene glycol methyl ether (2PG1ME), with production volumes from 1,00,000 to 10,00,000 tons/year. Glycol ethers are mentioned in three distinct categories in the questionnaires used in the French occupational programs: Ethylene glycol derivatives that are non-classified as CMR (carcinogenic, mutagenic, or toxic for reproduction) according to the CLP regulation: EGnPE, EGiPE, EGBE, EGBEA, EGHE, EGPhE, DEGEE, DEGEEA, DEGBE, DEGBEA, DEGHE, TEGME, TEGEE, TEGBEPropylene glycol derivatives that are non-classified as CMR: 2PG1ME, 2PG1MEA, 2PG1EE, 2PG1EEA, 2PG1BE, DPGME, DPGBE, 2PG1PhE, 1PG3ME, PGDEE, PGtBE, PGDME, DPGDME, DPGEE, DPGMEACMR glycol ethers: EGME, EGMEA, EGEE, EGEEA, EGDME, EGDEE, DEGME, DEGDME, TEGDME, 1PG2ME, 1PG2MEA.
Source analysis and health risk-assessment of ambient volatile organic compounds in automobile manufacturing processes
Published in Human and Ecological Risk Assessment: An International Journal, 2020
Ruipeng Tong, Xiaofei Ma, Yanwei Zhang, Guohua Shao, Meng Shi
To identify the specific processes that generated VOCs, we further explored these various working posts in each workshop. The main technological process, pollutant emission positions and chemical materials that produced VOCs in the automobile manufacturing process are shown in Table 3. In the press shop & body shop, the working post of producing VOCs was mainly the disassembling boundary and gelatinizing post. When the body of an automobile was processed by using dilated glue and edging adhesive in this working post, six VOCs were discharged, including benzene, toluene, xylene, ethyl acetate, butyl acetate and styrene. In the paint shop, the main working posts that generated VOCs were the gelatinizing post, basecoat post, topcoat post, repairing post and mixing paint post. Among them, the work at the gelatinizing post mainly involves applying PVC sealant on all welds of automobile bodies and applying anti-shock and anti-abrasion coatings on the underside of automobile bodies, which consumed a considerable amount of PVC adhesive and undercoat. The main jobs of the basecoat post were to carry out basecoat sanding on the automobile body and spray paint and background paint in the body cavity; these processes used raw materials, such as lacquer, base paint and PVC glue. In addition, a large amount of base coat, clear coating, diluent and curing agent were needed for the topcoat post, while the repairing work mainly required using glue, painting the defective automobile bodies, and using a small amount of paint materials. There were various types of lacquer-related raw materials in the mixing paint post. After statistical analysis, the consumption of raw materials in the various working posts of the paint shop released 14 VOCs, including benzene, toluene, xylene, ethylbenzene, ethyl acetate, butyl acetate, methanol, butanol, isopropanol, cyclohexanone, styrene, methyl isobutyl ketone, ethylhexyl phthalate and propylene glycol methyl ether acetate.