Laser generated air contaminants released during laser cutting of fabrics and polymers

Environmental monitoring was conducted at an industrial facility to qualitatively identify the major contaminants generated while cutting fabrics and polymers with a 25 W CO2 continuous beam laser. Carbon monoxide, hydrogen cyanide, and particulates were also assessed, and a bulk sample of residue from the laser exhaust duct was analyzed for inorganic acids, pH, and volatile organic compounds. Samples were collected while cutting vinyl, acrylics, woven fabrics, felt, Formica(R), and Plexiglass(R). The laser parameters were standardized to allow for meaningful comparison of results for each target material. The volatile organic compound samples were collected in multibed sorbent tubes with subsequent analysis via thermal desorption and gas chromatography/mass spectroscopy. Depending on the material being cut, a wide variety of compounds were detected. The highest relative concentrations of volatile compounds were found during laser cutting of felt fabrics. The lowest concentrations and fewest number of compounds were from woven fabrics. The compounds detected included hydrochloric acid, aldehydes, benzene, vinyl chloride, various acrylates, acrylonitrile, acetonitrile, styrene, furans, phenol, and butyl cellosolve. Methyl methacrylate was a significant peak detected during the laser cutting of acrylic ester polymers, Plexiglass, and polyvinyl chloride with adhesive backing. Carbon monoxide was not detected above background (2 ppm) during any of the laser cutting trials. Hydrogen cyanide was detected during the laser cutting of felt (15 ppm) and Formica(R) (8-10 ppm). Particles greater than or equal to 0.3 mu m in diameter (mu md) generated during the laser cutting exceeded background particle levels by a factor of ten or more. Most compounds detected in the thermal desorption air samples were also detected in the bulk sample, and the residue was acidic (pH = 3). Area samples collected outside the laser enclosure suggested the local exhaust ventilation system sufficiently contained the air contaminants.