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Standard Operating Procedures (SOPs) for Residential Exposure Assessments

APPENDIX A

Summary of Assumptions for the Residential SOPs

September 16, 1997

Table A-1. Summary of Assumptions for the Residential SOPs

Scenario Assumption Input Descriptor Reference Output Descriptor
2.1 Turf - Handler PHED surrogate data central tendency PHED V1.1 central tendency to high-end
20,000 ft² full lawn mean to upper percentile Vinlove and Torla, 1995
1,000 ft² or 5 gallons spot treatment upper percentile default values, 5 gallons represent two 2.5 gallon handwand containers HED
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg average of median for male/female U.S. EPA, 1996a
2.2 Turf - Post 20% of application rate is available as dislodgeable upper percentile HED high-end
Residue dissipation must be based on chemical-specific data -- --
Adult Tc = 43,000 cm²/hr Toddlers Tc = 8,700 cm²/hr mean Cal EPA, 1996 (Tc from carpet study)
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a
Toddlers (3 yrs) and adults exposed 2 hrs/day 95th percentile for playing on grass is 121 minutes/day for 1 to 4 yrs old and 18 to 64 yrs old U.S. EPA 1996a
2.3.1 Ingestion of Pellets/Granules - Post 0.3 g/day ingestion @ age 3 assumed upper percentile HED; derived based on application rate of 150 lbs product/ half acre high-end
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a
2.3.2 Nondietary Ingestion, Hand-to- Mouth 20% of the application rate is available as dislodgeable upper percentile HED high-end
Residue dissipation must be based on chemical-specific data -- --
3 yr old hand surface area 350 cm² mean of the median total surface areas for males and females in the 2 to 3 and the 3 to 4 yr age groups multiplied by the average percentage of the total body represented by the hands U.S. EPA 1996a
One-to-one relationship betwen dislodgeable residues on turf and on hands assumed --
Hand-to-mouth activity is 0.026 events/minute for 3 to 5 yr old mean U.S. EPA 1996b
Toddlers exposed 2 hrs/day 95th percentile for playing on grass is 121 minutes/day for 1 to 4 yrs old and 18 to 64 yrs old U.S. EPA 1996a
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a

Table A-2. Summary of Assumptions for the Residential SOPs (continued)

Scenario Assumption Input Descriptor Reference Output Descriptor
2.3.3 Ingestion of Turf 20 percent of application rate is available for ingestion upper percentile HED high-end
Residue dissipation must be based on chemical-specific data -- --
3 yr old ingestion rate of 25 cm²/day upper percentile HED; assumed to represent handful of grass
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a
2.3.4 Ingestion of Soil 100 percent of rate is within the uppermost 1 cm and is available for ingestion upper percentile HED; assumed high-end
Residue dissipation must be based on chemical-specific data -- --
1 to 6 yr old soil ingestion rate of 100 mg/day mean U.S. EPA 1996a
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a
3.1 Garden - Handler PHED surrogate data central tendency PHED V1.1
Substitute unit exposure from a hose-end sprayer for the sprinkler/watering can because no other data are available upper percentile assumption (central tendency value) assumed high-end
Substitute unit exposure from an aerosol can for the trigger pump because no other data are available upper percentile assumption (central tendency value) assumed
10,000 ft² area treatments upper percentile (large farm-setting or rural garden) HED
5 gallons of spray treatments upper percentile (two 2-1/2 gal handwand treatments) HED
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg mean of median for male/female U.S. EPA, 1996a
3.2 Gardens - Post 20% of the application rate is available as dislodgeable upper percentile HED high-end
Residue dissipation must be based on chemical-specific data -- --
Tc of 10,000 cm²/hr for adults and 5,000 cm²/hr for youth (10-12 years) mean HED
Exposure duration 0.33 hrs/day for toddlers age 1 to 4 yrs and 0.67 hrs/day for adults age 18 to 64 yrs 95th percentile for working in garden/soil U.S. EPA 1996a
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg mean of median for male/female U.S. EPA, 1996a

Table A-3. Summary of Assumptions for the Residential SOPs (continued)

Scenario Assumption Input Descriptor Reference Output Descriptor
4.1 Trees - Handler PHED surrogate data central tendency PHED V1.1 central tendency to hgh-end
5 gallons for runoff treatment upper percentile HED
1 gallon for brush-on treatments maximum HED
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg mean of median for male/female U.S. EPA, 1996a
4.2 Trees - Post 20% of the application rate is available as dislodgeable upper percentile HED high-end
Residue dissipation must be based on chemical-specific data -- --
Tc is 10,000 cm²/hr for adults and 5,000 cm²/hr for youth (10-12 years) mean HED
Exposure duration 0.33 hrs/day for toddlers age 1 to 4 yrs and 0.67 hrs/day for adults age 18 to 64 yrs 95th percentile for working in garden/soil U.S. EPA 1996a
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg mean of median for male/female U.S. EPA, 1996a
5.1 Pools - Handler PHED surrogate data central tendency PHED V1.1 central tendency
Pool size 20,000 gallons mean Kirk-Othmer 1984
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg mean of median for male/female U.S. EPA, 1996a
5.2.1 Pools - Ingestion 100 percent of application concentration is available for ingestion and no dissipation believed to be a reasonable assumption because ai is maintained at specific level in pool assumed high-end
0.05 L/hr ingestion rate for adults and children mean U.S. EPA 1989 and Dang 1996
Exposure duration is 5 hrs/day for children (6 yrs) and adults (18 to 64 yrs) 90th percentile U.S. EPA 1996a
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Children (6 yrs) weigh 22 kg mean of the median values for male and female age 6 yrs U.S. EPA 1996a

Table A-4. Summary of Assumptions for the Residential SOPs (continued)

Scenario Assumption Input Descriptor Reference Output Descriptor
5.2.2 Pools - Absorbed Dose 100 percent of application concentration is available for ingestion and no dissipation believed to be a reasonable assumption because ai is maintained at specific level in pool assumed high-end
Exposure duration is 5 hrs/day for children (6 yrs) and adults (18 to 64 yrs) 90th percentile U.S. EPA 1996a
Adult body surface area 20,900 cm² and children (6 yrs) body surface area 9,000 cm² means of the 90th percentiles for females and males U.S. EPA 1996a
Permeability coefficient (Kp) is chemical specific, see U.S. EPA 1992 for estimating Kp from Kow and MW -- U.S. EPA 1992
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Children (6 yrs) weigh 22 kg mean of the median values for male and female age 6 yrs U.S. EPA 1996a
5.2.3 Pools - Inhalation (Post) 100 percent of application concentration is available for ingestion and no dissipation believed to be a reasonable assumption because ai is maintained at specific level in pool assumed high-end
Exposure duration is 5 hrs/day for children (6 yrs) and adults (18 to 64 yrs) 90th percentile U.S. EPA 1996a
Inhalation rate of 1.7 m³/hr for adults (over 18 yrs) and 1.2 m³/hr for children (under 18 yrs) mean based on moderate activity U.S. EPA 1996a
Gas phase conc. based on ideal gas model and Raoult's Law -- Dang 1996
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Children (6 yrs) weigh 22 kg mean of the median values for male and female age 6 yrs U.S. EPA 1996a
6.1.1 Painting - Handler 3 cans/event of aerosol spray @ 12 ounces/cans 90th percentile (spray paint 36.11 oz/use) U.S. EPA 1996a high-end
2 gallons of paint with a paint brush 90th percentile (8 gallons/yr) divided by mean frequency of events (4 events/yr) U.S. EPA 1996a
2 gallons of paint with a paint roller 90th percentile (8 gallons/yr) divided by mean frequency of events (4 events/yr) U.S. EPA 1996a
5 gallons with low pressure hand pump deck-type stain sprayer not assigned HED
Three 5-gallon cans with an airless sprayer upper percentile derived based on coverage rate of 200 ft²/gallon and house size of 40ft x 30ft x 20ft (surface area 2,800 ft²)

Table A-5. Summary of Assumptions for the Residential SOPs (continued)

Scenario Assumption Input Descriptor Reference Output Descriptor
6.1.1 Painting - Handler (cont.) PHED surrogate data central tendency PHED V1.1
If paint roller study is not available, assume PHED exposure of the paint brush scenario central tendency HED
All paint categories (exterior alkyd and latex) are assumed to be similar -- assumed
Default density of spray paint is 1.24 g/mL mean density of latex paint U.S. EPA 1986
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg mean of median for male/female U.S. EPA, 1996a
6.3 Ingestion of Paint Chips Paint chip ingestion rate of 0.04 g/day for 6 month to 1.5 yrs old child upper percentile paint chip size ingested is assumed, avg. weight of paint chip U.S. EPA 1994 high-end/bounding
Infants (6 months to 1.5 yrs) body weight is 10 kg mean of median values for male and female children in the 6 to 11 month and 1 yr age groups U.S. EPA 1996a
20% of ai is remaining and is available for ingestion upper percentile HED; professional judgement
7.1 Foggers - Inhalation Outdoor space (e.g., yard) of 20 ft x 20 ft x 8 ft high = 3,200 ft³ central tendency HED; assumed high-end
Instant release of ai and dilution factor of 1 to 100 (1 percent) upper percentile HED; assumed
2 single use foggers upper percentile HED; assumed
Specific gravity of 0.80 g/mL mean CRC 1981
Adult inhalation rate of 0.55 m³/hr or 13.3 m³/day mean for males and females U.S. EPA 1996a
Toddlers (age 3) inhalation rate of 0.36 m³/hr or 8.7 m³/day mean U.S. EPA 1996a
Exposure duration for adults (18 to 64 yrs) is 5 hrs/day and 3 hrs/day for toddlers (1 to 4 yrs) 95th percentile for outdoors at restaurant/picnic areas U.S. EPA 1996a
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a
8.1 Indoor Crack & Crevice - Handler PHED surrogate data central tendency PHED V1.1 central to high-end
2 aerosol cans and 2 gallons for low pressure handwands upper percentile HED
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg mean of median for male/female U.S. EPA, 1996a

Table A-6. Summary of Assumptions for the Residential SOPs (continued)

Scenario Assumption Input Descriptor Reference Output Descriptor
8.2.1 Carpets - Post 50 percent of the application rate is available as dislodgeable. not assigned U.S. EPA 1993 central
Tc is 43,000 cm²/hr for adults, 8,700 cm²/hr for children, and 6,000 cm²/hr for infants (age 6 months to 1-1/2 years) mean U.S. EPA 1996c Cal EPA, 1996
Exposure duration of 8 hrs/day for adults (18 to 64 yrs) and children (1 to 4 yrs) mean of the median for adults and children U.S. EPA 1996a
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a
Infants (6 months to 1.5 yrs) body weight is 10 kg mean of median values for male and female children in the 6 to 11 month and 1 yr age groups U.S. EPA 1996a
8.2.2 Hard Surfaces - Post 50 percent of the application rate is available as dislodgeable. not assigned U.S. EPA 1993a central to high-end
Tc is 43,000 cm²/hr for adults, 8,700 cm²/hr for children, and 6,000 cm2/hr for infants (age 6 months to 1-1/2 years) mean U.S. EPA 1996c Cal EPA, 1996
Exposure duration is 4 hrs/day mean of the 90th percentile for adults (18 to 64 yrs) and toddlers (1 to 4 yrs) in the kitchen and bathroom U.S. EPA 1996a
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a
Infants (6 months to 1.5 yrs) body weight is 10 kg mean of median values for male and female children in the 6 to 11 month and 1 yr age groups U.S. EPA 1996a
8.4 Indoor Surfaces - Hand-to-Mouth 50 percent of application rate is available as dislodgeable not assigned U.S. EPA 1996c high-end
3 yr old hand surface area 350 cm² mean of the median of the total surface area for males and females in the 2 to 3 and the 3 to 4 yr age groups multiplied by the average percentage of the total body represented by the hands U.S. EPA 1996a
Tc is a one-to-one ratio maximum assumed
Hand-to-mouth activity rate is 0.026 events/minute for toddlers (3 to 5 yrs old) mean U.S. EPA 1996b
Exposure duration is 4 hrs/day mean of the 90th percentile for adults (18 to 64 yrs) and toddlers (1 to 4 yrs) in the kitchen and bathroom U.S. EPA 1996a
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a

Table A-7. Summary of Assumptions for the Residential SOPs (continued)

Scenario Assumption Input Descriptor Reference Output Descriptor
9.1.1 Pets - Handlers (Dips/Shampoo/Dust/Flea Collar) PHED surrogate data central tendency PHED V1.1 bounding
Homeowner is exposed to 10 percent of ai applied to pet upper percentile HED
Homeowner is exposed to 1 percent of ai in flea collar upper percentile HED
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg mean of median for male/female U.S. EPA, 1996a
9.1.2 Pets - Handlers (Aerosol) PHED surrogate data central tendency PHED V1.1 bounding
Application is the entire contents of product maximum assumed
Density of organic spray solution is 0.80 g/mL mean CRC 1981
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg mean of median for male/female U.S. EPA, 1996a
9.2.1 Pets - Post 20 percent of the application rate is available as dislodgeable upper percentile HED high-end
10 percent of the ai is transferred to the homeowner upper percentile HED
No dissipation over time maximum assumed
One animal is contacted per day -- assumed
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a
9.2.2 Pets - Hand-to-Mouth 20 percent of the application rate is available as dislodgeable upper percentile HED high-end
No dissipation over time -- assumed
3 yr old hand surface area 350 cm² mean of the median of the total surface area for males and females in the 2 to 3 and the 3 to 4 yr age groups multiplied by the average percentage of the total body represented by the hands U.S. EPA 1996a
Pet body surface area of 6,000 cm² (assumed 30 lb pet) mean Surface area calc. from U.S. EPA 1993b
Residue transfer is a one-to-one ratio maximum assumed
Hand-to-mouth activity for a toddler (3 to 5 yrs) is 0.026 events/minute mean U.S. EPA 1996b
Exposure duration is 2 hrs/day for toddlers upper percentile HED
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a

Table A-8. Summary of Assumptions for the Residential SOPs (continued)

Scenario Assumption Input Descriptor Reference Output Descriptor
11.2 Impregnated Materials - Post Skin surface area for mattresses is one-half the total surface area; 1 m² for adults and 0.35 m² for toddlers (age 3 yrs); surface area for shower curtains is one-tenth the total surface area; 0.2 m² for adults and 0.07 m² for toddlers (age 3) mean U.S. EPA 1996a central
Flux through impregnated materials is assumed the same -- assumed
Exposure time for mattresses 8 hrs/day; 0.5 hrs/day for shower curtains median U.S. EPA 1996a
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a
11.3 Impregnated Materials - Toddler Ingestion Surface area of the impregnated material (e.g., toy) is 500 cm² not assigned Dang 1997 high-end
Entire area of impregnated material is mouthed once per day -- HED
Toddlers (3 yrs) weigh 15 kg (represents 1 to 6 yrs) mean of the median for male/female U.S. EPA 1996a
13.1 Crack & Crevice - Inhalation Handler Indoors PHED surrogate data central tendency PHED V1.1 central to high-end
One aerosol can, 2 gallons of low pressure handwand, one shaker can upper percentile assumed
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weight 39.1 kg mean of median for male/female U.S. EPA, 1996a
15.0 Pick Your Own 20 percent of application rate is available as dislodgeable upper percentile HED high-end
Exposure duration of 2.0 hrs per day for toddlers and 4 hrs for adults median for time spent outdoors at a farm U.S. EPA 1996a
Tc is 5,000 cm²/hr for youth and 10,000 cm²/hr for adults not assigned HED
Adults (all adults 18+ yrs) weigh 71.8 kg mean U.S. EPA 1996a
Female (13 to 54 yrs) weigh 60 kg mean U.S. EPA 1996a
Youth (10-12 years) weigh 39.1 kg mean of median for male/female U.S. EPA, 1996a

References:

U.S. EPA (1996a) Exposure Factors Handbook. [Draft]. U.S. Environmental Protection Agency, National Center for Environmental Assessment, Washington, DC. EPA/600/P-95/002Ba.

Cal EPA (1996) Memorandum from T. Formoli (California EPA, Department of Pesticide Regulation, Worker Health and Safety Branch) to M. Mason (California EPA, Department of Pesticide Regulation, Pesticide Regulation Branch), October 17, 1996.

U.S. EPA (1996b) Time location activity pattern methodology: the creation of Bayesian distributions for the field investigations of exposure of infants and children to toxic substances. EPA-007-2. (To be included in an EPA Project Report entitled "Protocol for dermal exposure assessment in residential and non-occupational environments" which is currently in preparation and subject to EPA/ORD peer review).

CRC (1981) CRC Handbook of Chemistry and Physics, 61st Edition. CRC Press Inc. Boca Raton, Florida.

Kirk-Othmer (1984) Encyclopedia of Chemical Technology, 3rd Edition. Vol. 24, p. 427.

U.S. EPA (1989) Risk Assessment Guidance for Superfund. U.S. Environmental Protection Agency, Office of Emergency and Remedial Response, Washington, DC. EPA/540/1-89/002

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 (1993a) Protocol for Dermal Exposure Assessment: A Technical Report. U.S. Environmental Protection Agency, Environmental Monitoring Systems Laboratory. EPA/600/X-93/005.

U.S. EPA (1993b) Wildlife Exposure Factors Handbook. U.S. Environmental Protection Agency, Office of Research and Development, Washington, DC. EPA/600/R-93/187a.

Dang, W. (1996) The swimmer exposure assessment model (SWIMODEL) and its use in estimating risks of chemical use in swimming pools. EPA internal guidance document.

Vinlove, F.K., Torla, R. (1995) Comprehensive Estimation of U.S. Home Lawn Area. Journal of Turfgrass Management. 1(1):83-97.

U.S. EPA. (1996c) Assessment of Peak Performance System as a Tool for the Acquisition of Biomechanics Data Which May be Useful in the Calculation of Risks to Sensitive Populations. Prepared for the U.S. Environmental Protection Agency, Office of Research and Development, National Exposure Research Laboratory by Versar, Inc. Under Contract No. 68-D3-0013.

U.S. EPA (1992) Dermal Exposure Assessment: Principles and Applications. Office of Health and Environmental Assessment. EPA/600/8-9/011F.

Dang (1997) Risk Analysis for microban Additive "B" (Triclosan or Irgasan DP300) Treated Toys For Infants, Memo From Winston Dang (Antimicrobial Division) to Frank Sanders and William Jordan (Antimicrobial Division) Dated February 24, 1997.

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.


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