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Standard Operating Procedures (SOPs) for Residential Exposure Assessments
6.0 PAINTING AND WOOD PRESERVATIVE TREATMENTS
Prior to the development of an exposure assessment for painting scenario, the assessor should consult the pesticide label to determine if the scenario is appropriate based on the usage characteristics of the product. Specific labeling considerations for painting and wood preservative treatments are as follows:
Registered for Use in Paints or Wood Preservatives: Some paints, stains, and wood preservatives that contain pesticides do not have a pesticide label on their container and their labels do not make claims about pest control. The pesticide in these products is present as a biocide to preserve the product itself. Persons using these paint products are considered "secondary handlers," since they are not handling the pesticide itself -- they are handling products that contain pesticide as a general preservative. The SOP for exposure/risk assessments for such secondary handlers (and secondary post-application exposures) is in the biocide SOP under secondary exposures to general preservative uses. In order to determine the amount of pesticide in these products, the pesticide label for the biocide product must be obtained and the use-rate per gallon of paint product must be calculated.
Other paints, stains, and wood preservatives that contain pesticides have a pesticide label on their container. The labels of such products make claims about pest control, such as "kills mildew," "prevents wood rot," or "kills algae." These labels will contain an active ingredient statement indicating the amount of active ingredient in the container.
Limitation and Descriptive Statements: Look for statements describing or limiting the use of the paints, stains, or wood preservatives. These statements may be on the front panel of the label associated with the brand or trade name or in the use-directions section of the labeling. Assume that such products are used at residential sites unless a specific labeling statement indicates otherwise. Restricted-Use Pesticide classification and statements such as "For use by commercial or professional applicators only" indicate that the product cannot be bought or applied by homeowners. Therefore, no residential handler exposure/risk assessment is required. Since commercial applicators may apply pesticides to residential sites, a post-application exposure/risk assessment is required. Statements such as "For use in or on commercial buildings only," and the more specific "Not for use at residential sites," or "Not for use in and around homes or dwellings" indicate that the product cannot be used at residential sites and no residential handler or post-application exposure/risk assessment is required.
6.1 Handler - Dermal and Inhalation
6.1.1 Inhalation and Dermal Potential Doses from Painting/Staining in Residential Settings
Introduction
This SOP provides a standard method for completing dermal and inhalation exposure assessments for homeowners while painting with paint containing a pesticide. This scenario assumes that paint aerosols containing pesticides are available to be inhaled or dermal contact occurs while spraying, brushing, and rolling. Spray paint aerosols are assumed to be similar to that of an insecticide pressurized spray can application. All brush and roller paints and stains are assumed to be similar regardless of the paint type (e.g., alkyd or latex paints and stains). The method for completing exposure assessments for this scenario relies on using surrogate PHED data. Thus, this method should be used only in the absence of adequate data or as a supplement to existing data.
Methods for Estimating Dose
Label information is important for selecting appropriate data inputs for the exposure assessment (see Section 6.0). The data required include the application rate, the concentration of the pesticide active ingredient in the paint, the specific gravity of the paint product, the volume of the end-use product in the container, and the clothing scenario required by the label during painting. In the absence of actual data, the following assumptions are also used to calculate doses from painting:
- Daily dose is based on the amount of active ingredient handled per day and not the exposure duration (i.e., a single painting event per day).
- For aerosol spray paints, the upper-percentile assumption for the amount handled is 3 cans (12 ounces each) used per event ( the 90th percentile amount of spray paint used per event is 36.11 oz/use, U.S. EPA, 1996).
- For paints used with a brush, the amount of paint used per event is 2 gallons (two 1-gallon cans) of paint. This is based on a 90th percentile value of 8 gallons of latex paint used per year divided by the mean frequency of 4 painting events per year (U.S. EPA, 1996).
- For roller painting, it is assumed that a homeowner will use 2 gallons of paint. This is based on a 90th percentile value of 8 gallons of latex paint used per year divided by the mean frequency of 4 painting events per year (U.S. EPA, 1996).
- For painting/staining with a low pressure sprayer, it is assumed that homeowners may use up to 5 gallons product or of finished spray prepared from a concentrated product and water. This is based on the experience and professional judgement of the OPP/HED staff by assuming that more product would be used with a low pressure sprayer than with a roller or brush, but less than that used with a high pressure sprayer.
- For painting/staining with an airless sprayer, a homeowner is assumed to use three 5-gallon cans of ready-to-use product or of finished spray prepared from a concentrated product and water. This is based on a coverage rate of 200 ft2/gallon and a house size of 40x30x20 ft (surface area of 2,800 ft2). This is based on the experience and professional judgement of the OPP/HED staff and is assumed to be an upper-percentile input.
- The unit exposure values and comments regarding data confidence can be found in the Appendix B. The current version of PHED uses measures of central tendency to estimate the best-fit unit exposure.
- Unit exposure values for the application of a typical pesticide product from an aerosol can are assumed to be similar to that of an aerosol paint product.
- For rolling scenarios, unit exposure values are based on a single paint roller application study to be entered into PHED V2.0. In the event that the study is not available in PHED V2.0, the PHED value for the paint brush unit exposure is to be used. This is based on the experience and professional judgement of the OPP/HED staff and is assumed to be a central tendency value.
- Unit exposure values for a mixer/loader/applicator during the use of typical pesticide products using a low pressure handwand are assumed to be similar to that of a paint/stain being applied with a low pressure handwand.
- Unit exposure values for a mixer/loader/applicator during the application of a house stain using an airless sprayer are assumed to be similar for all paint/stain applications with these types of equipment. All airless sprayers are treated as similar equipment even though homeowners may use different devices.
- All paint categories are considered similar for exposure assessment purposes (e.g., an exterior alkyd paint would be considered the same as a latex).
- The density of spray paint is 1.24 g/mL. This is based on the mean density for latex paint. (U.S. EPA, 1986).
- Adults are assumed to weigh 71.8 kg (use 60 kg for females when the selected endpoint is from a reproductive or developmental study). A body weight of 71.8 kg represents the mean body weight for all adults (i.e., male and female, ages 18 years and older) and is the value recommended in U.S. EPA (1996). A body weight of 60 kg represents the mean body weight for females between ages 13 and 54 years (U.S. EPA, 1996). The mean body weight for a 10 to 12 year old youth is 39.1 kg. This represents the average of the median values for males and females at ages 10, 11, and 12 years.
The pounds of active ingredient applied per can(s) of paint (AR) can be calculated as follows: AR = V * ρ * (P/100) * (CF1)
where:
AR = amount of active ingredient applied for each can of
paint (lb ai/can)
V = volume of paint contained in each can (mL/can)
ρ = specific gravity of paint solution contained in can
(g/mL)
P = percent by weight of ai in the paint
CF1 = weight conversion factor (2.2E-3 lbs/g)
Inhalation and potential dose rates are calculated as follows: PDR = UE * AR * N
where:
PDR = potential dose rate (mg/day)
UE = unit exposure (mg/lb ai applied)
N = number of cans paint used per exposure day (cans/day)
Inhalation and dermal potential dose rates, normalized to body weight, are then calculated as: PDRnorm = PDR / BW
where:
PDRnorm = daily potential dose rate, normalized
to body weight (mg/kg/day)
BW = body weight (kg)
The body weight used can be adjusted to fit any specific scenario (e.g., exposure to male or female adults).
Example Calculations
The following example is for aerosol spray painting. The pounds of active ingredient applied for each can of spray paint applied (AR) can be calculated as follows assuming that the paint in this example comes in aerosol cans of 500 mL and has an ai content of 0.5 percent:
AR = V * ρ * (P/100) * CF1
AR = 500 mL/can * 1.24 g/mL * (0.5%/100) * 2.2E-3 lbs/g
AR = 6.8E-3 lb ai/can
The following is an example calculation to determine the dermal dose based on a single aerosol spray painting event, assuming a unit exposure value of 186.6 mg/lb ai.
PDR = UE * AR * N
PDR = 186.6 mg/lb ai * 6.8E-3 lb ai/can * 3 cans/day
PDR = 3.82 mg/day
The estimated dermal potential dose rate, normalized to body weight, for an adult with a body weight of 71.8 kg would be: PDRnorm = PDR / BW
PDRnorm = (3.82 mg/day) / (71.8 kg)
PDRnorm = 0.05 mg/kg/day
This dose would be used in conjunction with toxicity data to assess risk.
Limitations and Uncertainty
The dose estimates generated using this method are based on some central tendency (i.e., unit exposure values, density, body weight) and some upper-percentile (i.e., amount used per event) assumptions and are considered to be representative of high-end exposures. The uncertainties associated with this assessment stem from the use of a generic paint density and assumptions regarding the applicability of the selected unit exposure value (e.g., aerosols generated from a typical pesticide spray solution "behave" in similar fashion to a paint aerosol and associated data confidence for PHED generated value) . These assumptions are believed to be reasonable to calculate high-end doses based on observations from chemical-specific field studies and professional judgement.
References
U.S. EPA (1986) Standard Scenarios for Estimating Exposure to Chemical Substances During Use of Consumer Products -- Volume 1, Prepared for U.S. EPA, Office of Toxic Substances, Exposure Evaluation Division, by Versar, Inc. EPA Contract # 68-02-3968.
U.S. EPA (1996) Exposure Factors Handbook [Draft]. U.S. Environmental Protection Agency, National Center For Environmental Assessment, Washington D.C. EPA/600/P-95/002Ba.
6.2 Postapplication - Dermal (Refer to 11.2) and Inhalation (Refer to 13.2) (Indoor and Outdoor)
6.3 Postapplication Potential Dose Among Children from the Ingestion of Paint Chips Containing Pesticide Residues
Introduction
This SOP provides a standard method for estimating postapplication dose among children from ingestion of paint chips containing pesticide residues when adequate chemical-specific field data are unavailable. This scenario assumes that pesticide containing paint chips are ingested by children. This method should be used in the absence of actual field data.
Methods for Estimating Dose
Label information is important for selecting appropriate data inputs for the exposure assessment (see Section 6.0). The only datum required for estimating postapplication doses from paint chips containing pesticide residues is the percent ai content in the paint. In the absence of actual data, the following assumptions can be used for estimating daily pesticide postapplication doses.
- The assumed ingestion rate for paint chips containing pesticides is 0.04 gram/day for children (age 6 months to 1-1/2 year). This assumes that a child ingests a paint chip with an overall size of 1 in2 (6.25 cm2) and an average weight of 6.5 mg/cm2 for a paint chip that is one layer thick (U.S. EPA, 1994). This is believed to be an upper-percentile value.
- Infants (age 6 months to 1-1/2 year)are assumed to weigh 10 kg. This is the mean of the median values for male and female children in the 6-11 month and 1 year age groups. (U.S. EPA, 1996).
- Assume that 20 percent of the active ingredient is remaining in paint and is available for ingestion via paint chips. This is believed to be an upper-percentile assumption, based on the experience and professional judgement of the OPP/HED staff.
Potential dose rates from ingestion are calculated as follows: PDR = IgR * (P/100) * F * CF1
where:
PDR = potential dose rate (mg/day)
IgR = ingestion rate of paint chips containing pesticide residues
(g/day)
P = percent of ai in paint
F = fraction of ai available for ingestion (unitless)
CF1 = weight unit conversion factor (1,000 mg/g)
Potential dose rates, normalized to body weight, are calculated as: PDRnorm = PDR / BW
where:
PDRnorm = potential dose rate, normalized to body weight (mg/kg/day) BW = body weight (kg)
Example Calculations
The following is an example calculation to determine the dose based on an assumed quantity of 1 percent active ingredient in the paint chips containing pesticide residues. The estimated dose among children from ingestion of paint chips containing pesticide residues would be as follows:
PDR = IgR * (P/100) * F * CF1
PDR = 0.04 g/day * 0.01 * 0.20 * 1,000 mg/g
PDR = 0.08 mg/day
Finally, the estimated potential dose rate, normalized to body weight, for a child with a body weight of 15 kg would be:
PDRnorm = PDR / BW
PDRnorm = (0.08 mg/day) / (10 kg)
PDRnorm = 0.008 mg/kg/day
This dose would be used in conjunction with toxicity data to assess risk.
Limitations and Uncertainty
The dose estimates generated using this method are based on upper-percentile assumptions for the paint chip ingestion rate and amount of ai available for ingestion, and a central tendency estimate for body weight and are considered to be representative of high-end to bounding exposures. The uncertainties associated with this assessment stem from the use of an assumed ingestion rate of paint chips and an assumed amount of ai available in the paint chips. The estimated doses are believed to be reasonable high-end to bounding estimates based on professional judgement.
References
U.S. EPA (1994) Guidance Manual for the Integrated Exposure Uptake Biokinetic Model for Lead in Children. Prepared by the Technical Review Workgroup for Lead for EPA's Office of Emergency and Remedial Response. EPA 540-R-93-081.
U.S. EPA (1996) Exposure Factors Handbook [Draft]. U.S. Environmental Protection Agency, National Center For Environmental Assessment, Washington D.C. EPA/600/P-95/002Ba.
7.0 FOGGING
Prior to the development of an exposure assessment for a fogging scenario, the assessor should consult the pesticide label to determine if the scenario is appropriate based on the usage characteristics of the product. Specific labeling considerations for fogging are as follows:
Registered for Use as a Fog: Determine whether the labeling contains directions for use as a fog.
Limitation and Descriptive Statements: Look for statements describing or limiting the use of the fog. These statements may be on the front panel of the label associated with the brand or trade name or in the use-directions section of the labeling. Assume that a product registered for use as a fog is used at residential sites unless a specific labeling statement indicates otherwise. Restricted-Use Pesticide classification and statements such as "For use by commercial or professional applicators only" indicate that the product cannot be bought or applied by homeowners. Therefore, no residential handler exposure/risk assessment is required. Since commercial applicators may apply pesticides to residential sites, particularly indoors, a post-application exposure/risk assessment is required. Statements such as "For use in commercial livestock premises only," and the more specific "Not for use at residential sites," or "Not for use in and around homes or dwellings" indicate that the product cannot be used at residential sites and no residential handler or post-application exposure/risk assessment is required. Also, assume no residential uses if the directions for use are solely for application with a thermal fogger or other expensive fogging equipment.
7.1 Inhalation Doses Among Adults and Children After Pesticide Applications (e.g., Foggers) Outside of A Residence for the Purposes of Short-term Pest Control
Introduction
This SOP provides a standard method for completing postapplication inhalation exposure assessments for adults and children after a pesticide treatment outside their residence for the purposes of short-term pest control. The basis for this exposure scenario is that nonhandler inhalation exposure occurs while treated outdoor living spaces are occupied, typically for social gatherings, shortly after application of products intended for short-term pest control (e.g., fogging a yard or deck area prior to a party). This SOP addresses the use of several types of products including typical single use homeowner aerosol foggers, multi-use insecticide candles and torches, and other single use, slow release type products (e.g., impregnated solids that slowly burn over a given duration and emit pesticide containing fumes). The method for completing exposure assessments for all outdoor residential inhalation exposure scenarios where the application is intended for short-term pest control is based on assumptions.
Methods For Estimating Dose
If outdoor residential application is a potential scenario, information contained in the label of the product must be extracted for use as data inputs for the exposure assessment (see Section 6.0). The data required include the application rate, the concentration of the pesticide active ingredient in the product, the specific gravity of the product, the volume of the end-use product in the container, and any requirements for respiratory protection during handling activities. The following assumptions are also used to calculate bystander and postapplication inhalation doses from a pesticide product intended for short-term pest control:
- An outdoor living space with dimensions of 20 ft long x 20 ft wide x 8 ft high (i.e. 3200 ft3 or 90.62 m3) will be assumed to calculate airborne concentration levels. This is assumed to represent a central tendency value for the area of a yard that may be treated (this may also represent the size of a deck or patio), based on the experience and professional judgement of the OPP/HED staff.
- The emission is to be treated as an "instant release" scenario. All active ingredient is assumed to be "thrown up" in the air immediately. This is an assumption made in lieu of product-specific data. Although "instant release" is more applicable to the use of foggers than the use of candles or torches, this method is used as a simplified technique for assessing exposure and is assumed to represent a conservative (i.e., upper-percentile) approach. Further, the chemical is assumed to be diluted in outdoor air at a ratio of 1 to 100 [i.e., 1 percent (0.01) of the product released is available for exposure] and the pesticide is assumed to remain in the air at this concentration of the entire duration of exposure.
- The outdoor living space will be assumed to be treated with two single use, ready to use products such as a fogger.This is assumed to be an upper-percentile value based on the experience and professional judgement of the OPP/HED staff.
- All products are considered similar for exposure assessment purposes (e.g., emissions from a candle would be considered similar to a fogger).
- Most end use products included in this category are petroleum based. A specific gravity of 0.80 g/mL is assumed in all calculations unless a product specific value is available. This is based on an informal survey of various organic solvents described in CRC (1981). A value of 0.80 g/mL represents an mean of various organic solvents from this source.
- The adult inhalation rate is assumed to be 13.3 m3/day or 0.55 m3/hour for calculating daily exposures. This is the mean inhalation rate for males and females (U.S. EPA, 1996). A mean inhalation rate of 8.7 m3/day or 0.36 m3/hour is assumed for toddlers (i.e., age 3 years) (U.S. EPA, 1996).
- Occupancy of the treated outdoor living space is assumed to be 5 hours/day for adults (age 18-64 years) and 3 hours/day for toddlers (age 1-4 years). These values represent the 95th percentile values for time spent outdoors at a restaurant/picnic area for these age groups (U.S. EPA, 1996).
- Adults are assumed to weigh 71.8 kg (use 60 kg for females when the selected endpoint is from a reproductive or developmental study). A body weight of 71.8 kg represents the mean body weight for all adults (i.e., male and female, ages 18 years and older) and is the value recommended in U.S. EPA (1996). A body weight of 60 kg represents the mean body weight for females between ages 13 and 54 years (U.S. EPA, 1996). Toddlers (3 years old), used to represent the 1 to 6 year old age group, are assumed to weigh 15 kg. This is the mean of the median values for male and female toddlers. (U.S. EPA, 1996).
The grams of active ingredient applied using a container of product (AR) can be calculated as follows: AR = V * ρ * (P/100)
where:
AR = amount of active ingredient applied for each container
of end use product (grams ai/container)
V = volume of product solution contained in each container
(mL/container)
ρ = specific gravity of product in container (g/mL)
P = percent by weight of ai in the end use product solution
The concentration of the active ingredient available for inhalation exposure in the treated outdoor living space can be calculated as follow: Ca = (N * AR * F * CF1) / (V)
where:
Ca = outdoor air concentration in outside living
space available for inhalation exposure adjusted for dilution (mg/m3)
N = number of containers of end use product applied per use
event (i.e., N = 2 for all assessments completed using this SOP)
V = volume (m3) of outside living space (i.e.,
volume of 90.62 m3 will be used to calculate airborne
concentration levels outdoors in all cases)
F = fraction of chemical available in outdoor air for exposure
used to adjust amount of chemical released for "infinite dilution"
attributable to being outdoors (i.e., a value of 1 percent (0.01)
of the active ingredient released will be used for all calculations)
CF1 = weight unit conversion factor (1,000 mg/g)
Inhalation potential dose rates are calculated as follows: PDR = Ca * IR * ET
where:
PDR = potential dose rate (mg/day)
IR = inhalation rate (m3/hour)
ET = exposure time in treated outside living space (hr/day)
Inhalation potential dose rates, normalized to body weight, are then calculated as: PDRnorm = PDR / BW
where:
PDRnorm = potential dose rate, normalized to
body weight (mg/kg/day)
BW = body weight (kg)
The body weight and inhalation rate can be adjusted to fit any specific scenario (e.g., use of 60 kg for women when developmental endpoints are available).
Example Calculations
The following is an example calculation to determine the postapplication inhalation dose for an adult, based on a single treatment event using an aerosol fogger (i.e., 2 cans with an ai content of 1.5 percent). The grams of active ingredient applied for each can of fogger are calculated as follows:
AR = V * ρ * (P/100)
AR = (500 mL/container) * (0.80 g/mL) * (1.5%/100)
AR = 6.0 grams ai/container
The concentration of the active ingredient available for inhalation exposure in the defined outdoor living space is calculated as follows:
Ca = (N * AR * F * CF1) / (V)
Ca = (2 containers * 6.0 g ai/container * 0.01 * 1,000 mg/g) / (90.62 m3)
Ca = 1.32 mg/m3
Potential dose rates are calculated as follows:
PDR = Ca * IR * ET
PDR = 1.32 mg/m3 * 0.63 m3/hr * 5 hr/day
PDR = 4.16 mg/day
Potential dose rates, normalized to body weight, are then calculated as:
PDRnorm = PDR / BW
PDRnorm = (4.16 mg/day) / 71.8 (kg)
PDRnorm = 0.058 mg/kg/day
This dose would be used in conjunction with toxicity data to assess risk.
Limitations and Uncertainty
The dose estimates generated using this method are based on upper-percentile assumptions. The uncertainties associated with this assessment stem from the use of assumptions regarding the dilution of pesticides in outdoor air, and the amount and density of the product used. These assumptions are believed to be reasonable to calculate high-end estimates based on observations from similar field studies.
References
U.S. EPA (1996) Exposure Factors Handbook [Draft]. U.S. Environmental Protection Agency, National Center For Environmental Assessment, Washington D.C. EPA/600/P-95/002Ba.
CRC (1981) CRC Handbook of Chemistry and Physics, 61st Edition. CRC Press Inc. Boca Raton, Florida.