EPA-Expo-Box (A Toolbox for Exposure Assessors)
Exposure to chemicals in consumer products can be estimated by first defining the exposure scenario of interest. Exposure scenarios typically include information on the sources and pathways of exposure, contaminants of concern, and receptor populations. They might also describe a receptor population’s activities that may affect exposure and the timeframe over which exposure occurs.
The Importance of the Indoor Environment
On average, Americans spend about 90% or more of their time indoors, and indoor levels of pollutants may be 2–5 times higher, and occasionally more than 100 times higher, than outdoor levels of pollutants (http://www.epa.gov/greenbuilding/pubs/gbstats.pdf).
Consumer products may contain toxic or potentially toxic chemicals to which human receptors could be exposed directly as a result of their use in and around the home. Because people spend so much of their time indoors, consumer product use can be a significant source of exposure. By virtue of their use indoors, many of the contaminants from these products would be expected to remain indoors where they are used, increasing the likelihood of human contact with these contaminants. Nonusers (e.g., children) could be passively exposed to the contaminants released from these products.
Exposure to chemicals in consumer products might occur by incidental ingestion (e.g., from hand-to-mouth contact), dermal contact, or inhalation. Receptors could come into contact with contaminants from consumer products directly (during use) or indirectly (e.g., transfer of pesticide residues from indoor surfaces to the skin). Children are particularly susceptible via this indirect pathway because certain behaviors (e.g. tendency to mouth objects or hands) and activities (e.g., crawling or playing on the floor indoors) may increase their contact with contaminant-laden surfaces or dust (see the module on Lifestages in the Lifestages and Populations Tool Set of EPA-Expo-Box for more information). For any of these scenarios, concentrations of the contaminants from consumer products are needed to estimate the exposure dose. Contact with consumer products may be infrequent, intermittent, or short term (e.g., use of household repair product) or continuous and long term (e.g., use of solid air freshener).
After characterizing the exposed population and identifying exposure concentrations, it is important to define all appropriate exposure factor inputs to estimate potential exposures and risks. These inputs (e.g., dermal contact rates, ingestion or inhalation rates, frequency and duration of use, timeframe of exposure) can be obtained from the Exposure Factors Handbook: 2011 Edition (see Exposure Factors tab in the Indirect Estimation Module of Approaches Tool Set).
The table below provides resources with examples of scenarios involving consumer products. The list of examples is not meant to be exhaustive; there are numerous other consumer products scenarios that may be constructed based on the specific needs of the assessment. There are also numerous variations of the examples provided in the table. Additional information on exposure scenarios involving consumer products may be found in the Indirect Estimation Module in the Approaches Tool Set of EPA-Expo-Box.
|Consummer Product Type||Population||Activity/Timeframe||Use Rates||Exposure Period|
|Cosmetics, hygiene, and baby care products||Both genders||Amount product used per application and frequency of use;
|Product per application (grams); daily frequency of use
|Household solvent products||Both genders; users only||Frequency of use (number); per year||Yearly frequency of use
|Acute or subchronic|
|Household cleaning and maintenance products||Both genders||Exposure time (hours) of performing task; per year||Yearly frequency of use
|Interior paint||Both genders||Exposure time (hours) of painting activity; per occasion||Hours exposed/
|Acute or subchronic|
|Adhesive Remover||Both genders||Amount product used per application, frequency of use, exposure time; over the past year||Number of uses, minutes exposed, ounces of product used/past year
|Acute or subchronic|
|Humidifier||Both genders; by age group||Humidifier use at home (number of people); daily, per week, per month||Number of respondents for varied frequencies
|Subchronic or chronic|
Several resources are available that illustrate consumer products scenarios.