Emissions testing of two photocopiers with different design characteristics, using a new pre-equilibrium method and toner heating.

摘要

To reduce the sampling time required for evaluating photocopier emissions, a new model, identified as the pre-equilibrium model, was developed as a part of this thesis. This newly developed model, the pre-equilibrium model, is faster and more accurate than both the equilibrium and E + 4 AX models. For this new model, sampling and photocopier operation were conducted simultaneously. The generation rate (mug/hr) was calculated using the sample mass and chamber operating parameters in an equation. There is no required sampling time as long as sufficient analyte is collected.; The pre-equilibrium model was used to determine if the emission rates for two photocopiers with different design characteristics were significantly different. Two photocopiers were tested; they differed in type of photoconductor, type of toner and fusing temperature. An evaluation of their emissions showed that the emission rates for TVOC and IVOCs differed significantly. The results that were comparable to the emission rates found in the limited literature on this subject.; Emission factors (mug/copy) were also calculated for TVOC and IVOCs. Use of these emission factors for estimating ambient concentrations in a typical office environment found that TVOC concentrations above the SBS-associated threshold of 0.5 mg/m3, and benzene concentrations above the NIOSH-recommended exposure limit could occur.; Since emissions were found to vary with different photocopier design characteristics, the role of toner as a source of emission variability was investigated. TVOC emissions from toner were examined for the same two photocopiers that had been tested in a chamber using the pre-equilibrium model. The toner TVOC mass lost was determined by heating samples for the two toners to their fusing temperatures long enough to melt the toner. The ratio of the toner mass changes were similar to the TVOC mass measurements from chamber tests, indicating that heating toner to its fusing temperature may provide a method for estimating the TVOC emissions during photocopier operation. These results suggested that the variable emissions between machine designs are due to differences in toner composition and fusing temperature.; Standardization of chamber testing, toner emissions measurements, and other methods to evaluate photocopier emissions is necessary for comparison of emissions from different photocopiers. Further research is needed to better understand the relationship of photocopier emissions to emissions from toner and photocopied paper, in order to mitigate the risk of adverse exposures in the office environment. (Abstract shortened by UMI.)