Emissions From Office Equipment

摘要

Indoor air quality (IAQ) is a global issue. Numerous studies by government and environmental health specialists have shown indoor air to be a significant environmental threat to human health. Typical contaminants in building are gases and particles, and may include volatile organic compounds (VOCs) such as formaldehyde and styrene; inorganic gases such as ozone and nitrogen oxides; and respirable particles. The air of a typical office building will have 200-500 different individual volatile organic compounds. Their sources are numerous in buildings and may include construction materials and furnishings, combustion sources, office equipment, cleaning processes and contaminated outdoor air being brought into the building. If the sources are significant and ventilation is insufficient in buildings, contaminant levels can increase to concentrations which can be irritating to people. In some cases, these emissions can produce unacceptable odors. Significant emissions testing has been conducted on construction materials and furnishings, such as flooring, ceiling systems, office furniture, and insulation. However, limited data have been obtained on office equipment operation. VOCs, ozone, and particle emissions have been associated with operating equipment, such as computers, printers, and photocopiers. Some studies have indicated that these emissions have resulted in headaches, mucous membrane irritation, and dryness of the throat, eyes, and nose. Limited guidance has been given on acceptable levels of ozone and other contaminants from office equipment, and regulations for permissible levels are not currently available. Outdoor air standards do exist in the United States for ozone and respirable particles, and these are frequently used as default standards for indoor air. Germany's Federal Environmental Agency has developed IAQ emissions criteria for ozone, styrene, and particles or dust for copiers and printers. Certain other voluntary criteria programs have been developed in the Unites States. This current study presents emissions data obtained during the operation of dry process photocopiers, laser printers, and computers. Studies have been conducted in dynamic environmental chambers designed to simulate normal room conditions. Temperature, relative humidity, and ventilation are controlled and the chamber is constructed and operated to allow measurement of low levels of contaminants, as found in indoor air. Results among the tested products have been compared. In addition, potential exposure concentrations in a room with this equipment operating have been determined and compared to existing standards and guidelines. This data and the measurement technologies can be used by manufacturers to understand the IAQ impact of their products, to evaluate health hazards, and to evaluate potential source reduction measures.