Exposure Assessment Tools by Media - Consumer Products

Overview

Contaminated media to which people may be exposed include air, water and sediment, soil and dust, food, aquatic biota, and consumer products. Consumer products may contain chemical constituents to which people might be exposed as a result of their use.

Examples of consumer products include cosmetics and other personal care products, cleaning and home maintenance items, furniture, building materials, automotive products, pesticides, and a variety of other items. Individuals who manufacture or use these products can be exposed via incidental ingestion, inhalation, and dermal contact. Nonusers, including children, can also be passively exposed to chemicals in these products.

Various tools are available for evaluating sources and releases of contaminants in consumer products, fate and transport processes, and potential exposure concentrations. Exposure factors, calculation tools, and guidance for assessing exposure to contaminants in consumer products are also discussed in this module.

Sources

Chemicals in consumer products can be a source of human exposure. They can be released into the environment as a result of their manufacturing, distribution, use, and disposal.

Human exposure can occur through intentional direct contact such as applying cosmetics or other personal care products to the skin. Unintentional direct contact can also occur. For example, contact with laundry detergent or surface cleaner while in use, or contact with pesticides from products used for gardening, lawn care, or pest control in the home could result in unintentional contact. Indirect contact (e.g., off-gassing from furniture or other materials; cleaning product residue on surfaces, clothing) can also occur.

Contaminants in consumer products can also result in general environmental contamination when they migrate to environmental media such as air; soil and dust; aquatic media; and biota, including those that are used as a source of food. For additional information on the sources of contaminants for these media, see the Air, Soil and Dust, Water and Sediment, Food, and Aquatic Biota Modules in the Media Tool Set.

Resources that provide information on contaminants found in consumer products are listed below.

Fate and Transport

Fate and transport processes “link” the release of contaminants at a source with the resultant environmental concentrations to which receptors can be exposed. When a contaminant is released from a source, it is subject to transport and transformation in the environment.

Compounds can also transfer from an environmental medium (e.g., air, soil, water) to biota, including plants and animals used as a food source. For additional information on the fate and transport of contaminants within environmental media and biota, see the Air, Soil and Dust, Water and Sediment, Food, and Aquatic Biota Modules in the Media Tool Set.

The fate and transport of chemicals released from consumer products will be generally governed by their physicochemical properties and the characteristics of the environment into which they are released. For example, chemicals with a high vapor pressure would be more likely to remain in the air compared with low vapor chemicals that might settle with dust on surfaces.

For chemicals released to indoor air, characteristics of the building (e.g., air exchange rates, ventilation, room volumes) will influence dispersion and concentrations of contaminants in indoor air. The residence time of contaminant-laden dust will be influenced by human behavior that removes dust such as frequency and duration of vacuuming.

For chemicals that are released or transported outdoors, meteorological factors (e.g., temperature, sunlight, wind, precipitation) would contribute to their fate and transport. For chemicals released to water, the nature of the water body—such as flow rates and water characteristics like pH, salinity, and dissolved oxygen level—would affect their fate and transport.

The following tools provide information related to the fate and transport of contaminants that might be found in consumer products. In some of these resources, physicochemical properties of contaminants are also described. See the Chemical Classes Tool Set for more information on the toxicity, physicochemical properties, and other characteristics of specific groups of chemicals including organics, inorganics and fibers, pesticides, and nanomaterials.

Concentrations

The concentrations of chemicals from consumer products to which humans are exposed from the manufacture, distribution, use, or disposal of these products may be determined based on measurements or modeling. Characterizing contaminant concentrations for an exposure scenario is typically accomplished using some combination of the following approaches:

• Sampling consumer products and measuring contaminant concentrations
• Modeling the concentrations based on source strength, media transport, and chemical transformation processes
• Using existing, available measured concentration data collected for related analysis or compiled in databases

Tools that may be used to estimate exposure concentrations associated with consumer product use are provided in the table below.

Exposure Scenarios

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.

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. This might increase 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.  This is 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 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.

Several resources are available that illustrate consumer products scenarios.

Exposure Factors

To estimate human exposure to chemicals in consumer products, exposure factor information is needed. Exposure factors are human behaviors and characteristics that help determine an individual's exposure to an agent.

Potential routes of exposure to chemicals released from consumer products include inhalation of particulates, vapors, or aerosols; dermal contact from direct application to the skin (e.g., cosmetics) or contact with residues on surfaces; and incidental ingestion via hand-to-mouth or object-to-mouth contact. Depending on the scenario(s) being evaluated, inhalation rates, ingestion rates, dermal exposure factors such as body surface area, and/or activity-specific factors might be needed.

Data on consumer product use are available in Chapter 17 of EPA’s Exposure Factors Handbook: 2011 Edition, also refered to as the "Handbook." Specifically, Chapter 17 presents summaries of data from consumer product surveys on the amount of product used, the frequency of use, and the duration of use for various consumer products typically found in consumer households.

The Handbook categorizes consumer products that are commonly found in U.S. households as follows:

• cosmetics,
• hygiene, and
• baby care products;
• household furnishings;
• garment conditioning products;
• household cleaning and maintenance products;
• home building or improvement products;
• automobile-related products; and
• personal materials

Chapter 17 does not provide a summary of recommended exposure values related to consumer product use–like those summaries provided for other chapters in the Handbook–due to the large range and variation among consumer products and their exposure pathways.

Body surface area, dermal adherence of solids to skin, skin transfer efficiencies, and other factors needed for assessing dermal contact are available in Chapter 7 of the Handbook. Chemical-specific factors related to dermal absorption and internal dose, however, are not provided in Chapter 7.

Other activity-specific factors that might be relevant for assessing exposures with contaminants from consumer products are available in Chapter 16 of the Handbook, and these might include time spent indoors, time spent outdoors, or time spent doing specific activities (e.g., cleaning, gardening).

Other exposure factors that may be needed for assessing exposures to contaminants in consumer products include:

• Non-dietary factors such as mouthing frequency (Chapter 4)
• Soil and dust ingestion rates (Chapter 5)
• Inhalation rates (Chapter 6)
• Body weight (Chapter 8)
• Life expectancy values, specifically when evaluating cancer risk (Chapter 18)

Calculation Tools

A variety of tools are available for quantifying exposures (dose) and risks to human populations associated with chemicals in consumer products. These tools have typically been developed for specific situations or program offices, but may be tailored to meet the needs of the user.

Guidance

A number of guidance documents are available that support various aspects of consumer product safety programs at EPA and other agencies.