Under authority of the Clean Air Act, the University of Nevada, Reno (UNR) is required to maintain an air emissions permit for campus laboratory hoods. Regulation and enforcement of this permit has been delegated by the U.S. Environmental Protection Agency to the local Health District. As a condition of the permit, UNR must provide the local regulators with an annual estimate of chemical emissions from laboratory hoods. In 2004, UNR entered into a compliance agreement with the regulators to achieve compliance with the reporting requirement. As stipulated by the regulators, air emissions must be estimated using a mass-balance equation which includes terms for chemical inventory, purchase, and waste disposal data. All Hazardous Air Pollutants (HAPs) and “volatile chemicals” (VOCs) must be accounted for in the annual emissions report. In 2005, the first year UNR generated the report, over 500 individual chemicals met these criteria. This presentation will discuss the methodology used to generate the air emissions report, the resulting failures of the mass-balance approach, and subsequent regulatory and corrective actions. Despite the reporting issues, the regulatory action and resulting programmatic changes have improved the ability of the EH&S department to track and manage hazardous chemicals at UNR.