A well-mixed room model for estimating consumer exposure to ingredients used in air refreshener products

抄録

The completion of a scientifically sound safety assessment of new ingredients and finished products is essential prior to their introduction into the market place. Such assessments are based on a risk assessment paradigm established by the US National Academy of Science that consists of a four-step process: hazard identification, dose-response assessment, exposure assessment, and risk characterization. Within the risk assessment process for an air refreshener (AR) product, a well-mixed room model was used to estimate consumer exposure to the product ingredients. Consumers may be exposed to product ingredients via inhalation of the air in the room in which the product is used. The model represents a reasonable worst-case exposure scenario by conservatively assuming that ingredients are immediately mixed with the air in a room where the product is used and ingredients of concern are removed from the room through air change only. The well-mixed room model was formulated into a spreadsheet model and specifically parameterized for AR products through a thorough understanding of consumer habits and practices (H&P) in market places. Key parameters include: 1) Volume of the room (For a small bathroom or room the recommended default is 10 m3), 2) Time Period of Product use/emission (0.037 min), 3) Total time spent in room (42 min), 4) Number of Air Exchanges per hour (0.52, Shinohara et al., 2006), and 5) Total amount of product released (2310 mg). The well-mixed room model is currently employed in a risk assessmentbased approach to safety evaluation of AR products at Procter & Gamble. This presentation will describe the source of the H&P data, the model formulation and demonstrate exposure and risk assessment for representative ingredients.