Occupational exposure to organic solvents during paint stripping and painting operations in the aeronautical industry

Summary

The exposure of workers to methylene chloride and phenol in an aeronautical workshop was measured during stripping of paint from a Boeing B 747. Methylene chloride exposure was measured during two work days by personal air sampling, while area sampling was used for phenol. During paint stripping operations, methylene chloride air concentrations ranged from 299.2 mg/m³ (83.1 ppm) to 1888.9 mg/m³ (524.7 ppm). The exposures to methylene chloride calculated for an 8-h work day ranged from 86 mg/m³ (23.9 ppm) to 1239.5 mg/m³ (344.3 ppm). In another aeronautical workshop, exposure to organic solvents, especially ethylene glycol monoethyl-ether acetate (EGEEA), was controlled during the painting of an Airbus A 320. The external exposure to solvents and EGEEA was measured by means of individual air sampling. The estimation of internal exposure to EGEEA was made by measuring its urinary metabolite, ethoxyacetic acid (EAA). Both measurements were made during the course of 3 days. The biological samples were taken pre-and post-shift. During painting operations, methyl ethyl ketone, ethyl acetate, n-butyl alcohol, methyl isobutyl ketone, toluene, n-butyl acetate, ethylbenzene, xylenes and EGEEA were detected in working atmospheres. For these solvents, air concentrations ranged from 0.1 ppm to 69.1 ppm. EGEEA concentrations ranged from 29.2 mg/m³ (5.4 ppm) to 150.1 mg/m³ (27.8 ppm). For biological samples, the average concentrations of EAA were 108.4 mg/g creatinine in pre-shift and 139.4 mg/g creatinine in post-shift samples. Despite the fact that workers wore protective respiratory equipment during paint spraying operations, EEA urinary concentrations are high and suggest that percutaneous uptake is the main route of exposure for EGEEA. The introduction of new paint stripping processes in the aeronautical industry could help to reduce future exposure to methylene chloride.