Presently, no standard test method exists to evaluate the various emissions from office equipment (e.g., ozone, volatile organic compounds, inorganic gases, and particulates) so it is difficult to compare data from different studies.1 As a result, the authors are developing a standardized guidance document for measuring indoor air emissions from office equipment. The ultimate goal is to apply the test method to better understand emissions from office equipment and to develop lower emitting machines. This paper provides background information on indoor air emissions from office equipment with an emphasis on dry-process photocopy machines. The test method is described in detail, along with the results of a study to evaluate the test method using four dry-process photocopy machines. The results from this study indicate that the test method provides acceptable performance for characterizing emissions; that it can adequately identify differences in emissions between machines both in compounds emitted and their emission rates; and that it is capable of measuring both intra- and inter-machine variability in emissions. Challenges and complications were encountered in developing and implementing the test method. These included heat generation, which can cause large increases in chamber temperature; finite paper supplies for photocopy machines, which limit test duration; varying power requirements that may require changes in chamber electrical supply; and remote starting of the machines, which is necessary to maintain chamber integrity. Results show that dry-process photocopy machines can produce emissions of ozone and volatile organic compounds that can potentially have a significant impact on indoor air quality. For the four machines tested in this study, the compounds with the highest emission rates overall were ethylbenzene (28,000 µg/hour), m,p-xylenes (29,000 µg/hour), o-xylene (17,000 µg/hour), 2-ethyl-lhexanol (14,000 µg/hour), and styrene (12,000 fig/hour). Although many of the same compounds tended to be detected in emissions from each of the four photocopiers, the relative contribution of individual compounds varied considerably between machines, with differences greater than an order of magnitude for some compounds.

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The nature of both indoor air exposures and noncancer end points present nt issues for risk characterization. Noncancer end points are multidimensional, affecting various organs, and are assmed to have trsholds. Symptoms also vary in severity within a population. In addtion tothe compexkity of n risk at, indoor ir exposures are typified by the presence of complex mixtures, which furtber complictes the compex nature of noncancer risk characterization. Most noncancer risk asssment efforts have focused on defaing acceptable daiy intakesor reference doses (RfD) rather than estimating incidence and severity of the wide nnge ofefects witn an eposed potion. The risk characterization frnaework has been developed to acmmodate the RID approach but, more importantly, to address the multidimensional nature ofnoncancer risk characteriation. Newly emerging methods and standard EPA risk assessment guidelines for noncancer effects and complx mixtures were used as guides for dhopngthe fraework. Information and data needs have been identified from the framework. Peak, average, and cumulative doses from indoor air exposures are highly dependent on variable indoor air concentrations and affected by time-activity patterns. Susceptibility also plays a significant role in noncancer end points and, unlike susceptibility in cancer risk at, is quantifable. his paper jlihts the risk characterization frmework for nocancer heath risks tat wede oloped in cooperation with the U.S Environmental Protection Agency Environmental Criteria and n t Office. Additionally, a preliminary application of the framework to a complex mixture of volatile organic compounds from indoor sources is illustrated.

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