Health hazard evaluation report: HETA-99-0109-2754, VideoJet Systems, International, Wood Dale, Illinois.
On February 17, 1999, the National Institute for Occupational Safety and Health (NIOSH) received a management request for a health hazard evaluation at VideoJet Systems International, Inc., (VSI) in Wood Dale, Illinois. The request asked NIOSH to characterize laser-generated air contaminants (LGAC) and evaluate the potential hazards during the laser marking of various materials and ink-coated products. No health problems had been reported, however the laser developers were concerned about potential exposures to VSI research and maintenance personnel, as well as end users (product stewardship). Additionally, NIOSH was asked to evaluate a ventilation system and recommend appropriate safety measures. An initial site visit was conducted on March 15, 1999, to review the laser marking process and develop an appropriate evaluation strategy. A follow-up visit to collect air samples during the laser marking of different substrates, and evaluate the ventilation system, was made on May 18-19, 1999. During this follow-up visit, environmental monitoring was conducted to qualitatively identify major contaminants generated during the marking of 13 different substrates. Instantaneous samples for carbon monoxide (CO), hydrogen cyanide (HCN), and particulate were also collected using direct reading instrumentation, and a bulk sample of the filter used in the laser exhaust system was analyzed. Approximately 250 different compounds were qualitatively identified on the thermal desorption tubes and filter extracts. The highest relative concentrations of volatile compounds were found on the plastic materials, the lowest from materials such as glass, cardboard, and ceramic. Compounds including hydrochloric acid, benzene, styrene, methyl methacrylate, and vinyl chloride were detected from the laser marking of polyvinyl chloride; alkyldienes, alkenes, and alkanes were detected from the marking of high density polyethylene bottles. Phenols and cresols were the major compounds detected from marking plastic integrated circuits. Laser marking on the polyethylene terepthalate (PET) plastic materials generated benzene, toluene, styrene, benzoic acid, phenol, and acetophenone. Traces of polycyclic aromatic hydrocarbons were detected on several samples (i.e., plastic integrated circuit). No HCN was detected in the plume of any materials marked. In general, the number of particles 0.3 micrometers in diameter (umd) and 1.0 umd generated during the laser marking exceeded background particle levels by a factor of 10 or more for the polymer products. Particles were also higher than background for the other test materials (cardboard, glass, ceramic), but not to the same degree as the plastics. CO was detected at higher than background levels on 77% of the materials tested. The highest CO levels (90-100 parts per million) were measured during the laser marking of PET. Finally, the monitoring results indicated that the exhaust ventilation being used in -place on the laser marking system was adequately controlling the LGACs generated during the marking trials for this evaluation.