Appendix C. Exposure Factors and Assumptions 
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TABLE OF CONTENTS 

C-1 Introduction .................................................................................................................... C-1 

C-2 Age of Exposed Individual .............................................................................................. C-1 

C-3 Body Weight ................................................................................................................... C-2 

C-4 Ingestion Rates .............................................................................................................. C-2 

C-4.1 Drinking Water Intake ............................................................................................. C-3 

C-4.2 Soil Ingestion .......................................................................................................... C-3 

C-4.3 FFC Ingestion ......................................................................................................... C-5 

C-4.4 Fish Ingestion .......................................................................................................... C-6 

C-4.5 Breast Milk Ingestion ............................................................................................... C-7

C-5 Exposure Frequency ...................................................................................................... C-8 

C-6 Fraction Contaminated ................................................................................................... C-8 

C-7 Cooking Loss ................................................................................................................. C-8 

C-8 References ................................................................................................................... C-10 
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LIST OF TABLES 

Table C-1. Mean and Percentile Body Weight Estimates for Adults and Children................... C-2 

Table C-2. Estimated Daily Per Capita Mean and Percentile Water Ingestion Rates 

|for Children and Adults ......................................................................................... C-4 

Table C-3. Daily Mean and Percentile Soil Ingestion Rates for Children and Adults ............... C-4 

Table C-4. 90th Percentile and Mean, Age-Specific Ingestion Rates for the FFC Pathway ..... C-5 

Table C-5. 90th Percentile and Mean Fish Ingestion Rates ...................................................... C-6 

Table C-6. Calculated Mean and 90th Percentile Per capita Fish Ingestion Rates for Select 

Populations of Recreational Fishers ...................................................................... C-7 

Table C-7. Breast Milk Ingestion Rates for Infants Less Than 1 Year of Age .......................... C-7 

Table C-8. Fraction Weight Losses from Preparation of Various Foods .................................. C-9 
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C-1 Introduction 

For this multipathway risk assessment, human exposures (i.e., intake rates) of persistent and 

bioaccumulative hazardous air pollutants (PB-HAPs) were estimated with the Multimedia 

Ingestion Risk Calculator (MIRC). MIRC calculates intakes using a number of exposure factors, 

including assumptions about age and body weight of the exposed individual, the ingestion rate 

of each source of exposure (e.g., fruits and vegetables, fish), and others. Collectively, the 

exposure factor values used in a multipathway assessment represent an “exposure scenario,” 

or a set of assumptions about the nature and degree of exposures expected to occur. The 

exposure scenarios used for this assessment are described in Section 3 of the main report. 

This appendix provides additional detail about the exposure factors and the exposure factor 

assumptions built into MIRC. 

The exposure factors used for this assessment were derived from EPA’s risk assessment 

guidance and other reliable and defensible sources. For example, the ingestion and body 

weight exposure factors were obtained primarily from EPA’s (1997a, b) Exposure Factors 

Handbook (hereafter referred to as EFH). The discussions of each exposure factor in this 

appendix identify the basis of the values built into MIRC. 

C-2 Age of Exposed Individual 

In 2005, EPA recommended a standard set of child age categories for exposure and risk 

assessments (EPA 2005). In Chapter 13 of both its EFH (EPA 1997a) and its Child-Specific 

Exposure Factors Handbook (EPA 2008), hereafter referred to as CSEFH, EPA summarized 

home-grown/raised food ingestion rates for four children’s age groups: 1 to < 3 years; 3 to < 6 

years; 6 to < 12 years; and 12 to < 20 years. MIRC estimates exposures and risks separately 

for four children’s age groups and for adults 

For purposes of developing MIRC, however, the designation of age categories was limited by 

the categories for which most of the published FFC food ingestion rates have been calculated. 

The U.S. Department of Agriculture’s (USDA’s) 1987-1988 Nationwide Food Consumption 

Survey (USDA 1994) remains the most recent survey of ingestion rates for home-grown foods, 

and EPA’s analysis of those data, published in its 1997 EFH, remains the most recently 

published major analysis of those data. Because ingestion of home-grown produce and animal 

products are the primary exposure pathways for which MIRC was developed, those are the age 

groupings used for all child parameter values used to estimate exposure and risk in MIRC. 

Thus, in MIRC, values for each exposure parameter were estimated for adults (20 to 70 years) 

and five children’s age groups: 

 Infants under 1 year (i.e., 0 to < 1 year); 

 Children ages 1 through 2 years (i.e., 1 to < 3 years); 

 Children ages 3 through 5 years (i.e., 3 to < 6 years); 

 Children ages 6 through 11 years(i.e., 6 to < 12 years) and 

 Children ages 12 through 19 years (i.e., 12 to < 20 years). 

Exposure and risks to infants under 1 year of age are estimated only for the breast-milkingestion pathway. 
4/28/2011 C-2 

C-3 Body Weight 

Body weight (BW) options included in MIRC include mean, 5th, 10th, 50th, 90th, and 95th

percentiles for adults and the five children’s age groups. The BW values are listed in Table C-1. 

For adults, BW represents the weighted average of male and female mean body weights for all 

races, ages 18-74 years, from EPA’s EFH (1997a, b). In general, BW values for the five 

children’s age groups were calculated from the summary data provided in Mean BWs are used 

as default values in MIRC. For its default screening assessment, EPA uses the mean BW for 

each age group. 

In addition to the values shown in Table C-1, the breast milk exposure module in MIRC includes 

a default nursing mother BW of 66 kg. This value is from EPA (2004). 

Table C-1. Mean and Percentile Body Weight Estimates for Adults and Children

Life stage 

(years) 

Duration 

(years) 

Body Weight (kg) 

Mean 5th 10th 50th 90th 95th

Adult a (20-70) 50 71.4 52.9 56.0 69.3 89.7 97.6 

Child < 1 b 1 7.83 6.03 6.38 7.76 9.24 9.66 

Child 1-2 c 2 12.6 9.9 10.4 12.5 14.9 15.6 

Child 3-5 d 3 18.6 13.5 14.4 17.8 23.6 26.2 

Child 6-11 e 6 31.8 19.7 21.3 29.3 45.6 52.5 

Child 12-19 f 8 64.2 39.5 45.0 64.2 83.5 89.0 a

 BW represents the sample-size weighted average of male and female mean body weights (all races, 18-74 

years) from EPA (1997a) (Tables 7-4 for males and 7-5 for females). Note that these weights include the weight 

of clothing, estimated to range from 0.09 to 0.28 kg. Although the 18 to 74 year age category in EPA’s EFH 

(1997a) does not match exactly the age 20 to 70 year categorization of adults in MIRC, the magnitude of error in 

the mean and percentile body weights is likely to be very small (i.e., less than 1%). 

b

 Each BW represents a time-weighted average of body weights for age groups birth to <1 month, 1 to <3 

months, 3 to <6 months, and 6 to <12 months from Table 8-3 of the 2008 CSEFH. Original sample sizes for 

each of these age groups can also be found in Table 8-3.

c

 Each BW represents a time-weighted average of body weights for age groups 1 to <2 years and 2 to <3 years 

from Table 8-3 of the 2008 CSEFH. Original sample sizes for each of these age groups can also be found in 

Table 8-3.

d BWs obtained directly from Table 8-3 of the 2008 CSEFH (age group 3 to <6 years). e

 BWs obtained directly from Table 8-3 of the 2008 CSEFH (age group 6 to <11 years). This value represents a 

conservative (i.e., slightly low) estimate of BW for ages 6 through 11 years since 11-year olds are not included in 

this CSEFH age group.

f

Mean BW estimated using Table 8-22 of the 2008 CSEFH, which is based on NHANES IV data as presented in 

Portier et al. (2007). This estimate was calculated as the average of the 8 single-year age groups from 12 to 13 

years through 19 to 20 years. Values for the other percentiles were estimated using Portier et al., 2007. 

C-4 Ingestion Rates 

MIRC includes built-in, age-specific ingestion rate (IR) data for drinking water, soil, nine FFC 

items, and fish. Each of these, as well as breast-milk ingestion data, is discussed below. All 

default IRs in MIRC are 90th percentile values. 
4/28/2011 C-3 

C-4.1 Drinking Water Intake 

MIRC includes the option of calculating chemical ingestion via drinking water obtained from 

surface-water sources or from wells (i.e., from groundwater) in the contaminated area. Users 

have the option in MIRC to set drinking water ingestion rates to zero or to revise the drinking 

water ingestion rates in MIRC to better reflect site-specific water uses. Table C-2 includes the 

drinking water ingestion rates for adults and children that are included in MIRC. 

The drinking water ingestion pathway is not included in the proposed exposure scenarios for the 

secondary lead smelting multipathway assessment because surface water bodies are not likely 

to be used as a source of drinking water. 

C-4.2 Soil Ingestion 

Adult gardeners may incidentally ingest soils from gardening activities, and gardening and 

farming families might ingest soil particles that adhere to exposed fruits and exposed and 

belowground vegetables. Soils that are re-suspended in the air by wind can resettle on 

exposed fruits and vegetables. Children may incidentally ingest soils in those ways, but in 

addition, children playing outdoors may ingest soils directly or by hand-to-mouth activities during 

play. MIRC includes soil ingestion rate options by age group for these types of exposures. 

MIRC does not include options for children who may exhibit pica, or the recurrent ingestion of 

unusually high amounts of soil (i.e., on the order of 1,000 - 5,000 mg/day or more) (EPA 2008). 

Data on soil IRs are sparse; the soil ingestion rates listed in Table C-3 and included in MIRC are 

based on very limited data, as is evident from the values listed. The studies evaluated by EPA 

for children generally focused on children between the ages of 1 and 3 to 6 years and were not 

specific to families that garden or farm. 
4/28/2011 C-4 

Table C-2. Estimated Daily Per Capita Mean and Percentile Water Ingestion Rates for 

Children and Adultsa

Life stage (years) Ingestion Rates, Community Water (mL/day) 

Mean 50th 90th 95th 99th

Child <1 b 324 146 866 * 1,011 * 1,377 * 

Child 1-2 c 294 217 654 857 1,290 * 

Child 3-5 d 380 291 834 1,078 1,654 

Child 6-11 e 447 350 980 1,235 1,870 *

Child 12-19 f 697 516 1,537 2,022 * 3,195 * 

Adult g 1,098 920 2,224 2,801 4,488 

Sources: EPA 2004, 2008 

* The sample size does not meet minimum reporting requirements as described in EPA 2008. For some of these 

MIRC age groupings, the values are based on the time-weighted average value for 2 or more age ranges from 

CSEFH Table 3-4. One or more age ranges within the group may not meet the minimum reporting requirements, 

but not necessarily all of them fall within this category. a

 Source is Kahn and Stralka 2008, also presented in the CSEFH (EPA 2008). b

 Each IR represents a time-weighted average of ingestion rates for age groups birth to <1 month, 1 to <3 months, 

3 to <6 months, and 6 to <12 months from Table 3-4 of the 2008 CSEFH. c

 Each IR represents a time-weighted average of ingestion rates for age groups 1 to <2 years and 2 to <3 years 

from Table 3-4 of the 2008 CSEFH. 

d

 Each IR represents the ingestion rate for age group 3 to <6 years from Table 3-4 of the 2008 CSEFH. e

 Each IR represents the ingestion rate for age group 6 to <11 years from Table 3-4 of the 2008 CSEFH. This 

value represents a conservative (i.e., slightly low) estimate of IR for ages 6 through 11 years since 11-year olds 

are not included in this CSEFH age group. 

f

 Each IR represents a time-weighted average of ingestion rates for age groups 11 to <16 years, 16 to <18, and 18 

to <21 years from Table 3-4 of the 2008 CSEFH. Note that estimated values include 11-year-olds and individuals 

through age 20, which contributes to uncertainty in the estimates for 12 to 19 years. 

g

 Adult drinking water ingestion rates were obtained from EPA (2004), Appendix E, Part I, Table A1 for community 

water, both sexes (ages 20+), direct plus indirect water ingestion.

Table C-3. Daily Mean and Percentile Soil Ingestion Rates for Children and Adults

Age Group 

(years) 

Soil Ingestion Rate (mg/day) 

Mean a 50th a 90th 95th 99th

Child < 1 NA 

Child 1-2 50 50 400 b 400 b 400 b

Child 3-5 50 50 400 b 400 b 400 b

Child 6-11 50 50 201 c 331 d 331 d

Child 12-19 50 50 201 c 331 d 331 d

Adult 20-70 50 50 201 c 331 d 331 d

Sources: EPA 1997a, 2008 

a

 For the mean and 50th percentile soil ingestion rates for children, value represents a “central tendency” 

estimate from EPA’s 2008 CSEFH, Table 5-1. For adults, value is the recommended mean value for adults from 

EPA’s 1997 EFH, Chapter 4, Table 4-23. 

b

 These values are the recommended “upper percentile” value for children from EPA’s 1997 EFH, Chapter 4, 

Table 4-23. The 2008 CSEFH included a high-end value associated with pica only. 

c

 These values are 90th percentile adult ingestion rates calculated in Stanek et al. 1997, and they are used to 

represent older children and adults. 

d

 These values are 95th percentile adult ingestion rates calculated in Stanek et al. 1997, and they are used to 

represent older children and adults. 
4/28/2011 C-5 

C-4.3 FFC Ingestion 

MIRC includes mean, median, 90th, 95th, and 99th percentile food-specific IRs for consumers of 

FFC media for adults and children. The mean and percentile values are from EPA’s analysis of 

data from the USDA’s 1987 to 1988 Nationwide Food Consumption Survey (NFCS) (USDA 

1994), as presented in Chapter 13 (i.e., Intake Rates for Various Home Produced Food Items) 

of the EFH (EPA 1997a). All FFC IRs are consumers-only, meaning that individuals who did not 

report eating a specified type of food during the three-day period covered by the food ingestion 

part of the survey were not included in the analysis of ingestion rates for that food type. 

Table C-4 shows the 90th percentile and mean ingestion rates for the FFC pathways. Median, 

95th percentile, and 99th percentile IRs, although not shown, are available in MIRC or in EPA 

(2009). The units for the FFC IRs are in gwet weight/kgbody weight-day. As these units suggest, the 

FFC IRs are normalized for body weight. 

Table C-4. 90th Percentile and Mean, Age-Specific Ingestion Rates 

for the FFC Pathway

Product 

Age Group 

Units Child a

< 1 yr 

Child 

1-2 yrs 

Child 

3-5 yrs 

Child 

6-11 yrs 

Child 

12-19 yrs Adult 

90th Percentile Consumer Ingestion Rate 

Farm Food Item (wet weight) 

Beef NA f 4.5 6.7 11.4 3.53 5.39 g/kg-day 

Dairy c NA f 148 82 54.7 27.0 34.9 g/kg-day 

Eggs c NA f 5.1 2.8 1.80 1.34 1.65 g/kg-day 

Exposed Fruit NA f 3.7 5.4 6.98 3.41 5 g/kg-day 

Exposed Vegetable NA f 10.7 3.5 3.22 2.35 6.01 g/kg-day 

Pork c NA f 4.5 4.4 3.04 2.65 3.08 g/kg-day 

Poultry c NA f 7.4 6.8 4.58 3.28 3.47 g/kg-day 

Protected Fruit c NA f 53 36 24.1 16.2 15.1 b g/kg-day 

Protected Vegetable NA f 3.9 2.5 2.14 1.85 3.55 g/kg-day 

Root Vegetable NA f 7.3 4.3 3.83 2.26 3.11 g/kg-day 

Mean Consumer Ingestion Rate 

Farm Food Item (wet weight) 

Beef NA f 1.49 2.21 3.77 1.72 2.63 g/kg-day 

Dairy c NA f 67 37 24.8 10.9 17.1 g/kg-day 

Eggs c NA f 2.5 1.4 0.86 0.61 0.90 g/kg-day 

Exposed Fruit NA f 1.8 2.6 2.52 1.33 2.32 g/kg-day 

Exposed Vegetable NA f 3.5 1.7 1.39 1.07 2.17 g/kg-day 

Pork c NA f 2.2 2.1 1.49 1.17 1.30 g/kg-day 

Poultry c NA f 3.6 3.4 2.13 1.59 1.54 g/kg-day 

Protected Fruit c NA f 19 13 8.13 5.44 5.19 b g/kg-day 

Protected Vegetable NA f 2.5 1.3 1.1 0.78 1.3 g/kg-day 

Root Vegetable NA f 2.5 1.3 1.32 0.94 1.39 g/kg-day 

Source: EPA 1997a (Chapter 13), unless otherwise noted in table notes. See Attachment C-2 for additional 

information on sources. NA = not applicable. 

a

 Ingestion rates for produce and animal products are normalized to consumer body weight. Ingestion rates for soil 

(mg/day) and water (mL/day) are not normalized to body weight. 

b

 This value represents a weighted average for the 20-39 and 40-69 age groups. c

 In many cases, ingestion rates for certain child age groups were not available in EPA 1997a. Intakes for these 

receptor groups were calculated using the methodology recommended in HHRAP (EPA 2005) 

d

 This value represents an estimated “upper percentile” for children (EPA 1997a). e

 Values represent soil ingestion rates for individuals consuming homegrown food products from Stanek et al. 1997. f

 Infants are assumed to consume only breast milk for one year. 
4/28/2011 C-6 

C-4.4 Fish Ingestion 

The USDA’s 1987 to 1988 Nationwide Food Consumption Survey (NFCS) (USDA 1993, 1994a), as 

presented in Chapter 13 of the Agency’s Exposure Factors Handbook (i.e., Intake Rates for Various 

Home Produced Food Items) (EPA 1997a), includes family-caught fish ingestion rates by age 

category. There are several disadvantages, however, to using that data source to estimate fish 

ingestion rates. First, due to inadequate sample sizes, EPA did not report fish IRs for children less 

than 6 years of age. Second, the NFCS data were collected approximately two decades ago. 

Third, the reported fish IRs are for ages 6 to 11 and 12 to 19 and are based on 29 and 21 

individuals in each age category, respectively (EPA 1997a, Table 13-23). Finally, the IRs from 

NFCS data are based on total weight of fish as brought into the home, and do not include losses 

from preparation of the fish (i.e., removal of inedible parts and, possibly, the skin). Estimates of 

preparation losses for fish intended to apply to the NFCS fish IR data are very uncertain and are 

based on a wide variety of freshwater, estuarine, and marine fish, and squid (EPA 1997a, Table 13-

5). Therefore, a more recent survey was sought that included larger sample sizes, data for children 

younger than six years, and IRs for the parts of fish actually consumed. 

EPA’s (2002) analysis freshwater and estuarine fish consumption from the USDA’s Continuing 

Survey of Food Intake by Individuals (CSFII) for 1994-96 and 1998 was chosen to provide per 

capita fish IR options by age category in MIRC. Although the fish consumption rates reported in the 

CSFII include all sources, commercial and self-caught, for purposes of this assessment, it was 

assumed that all freshwater and estuarine fish consumed are self-caught. The inclusion of 

commercially obtained and estuarine fish will overestimate locally caught freshwater fish IRs for 

many rural populations in the United States; however, it also may underestimate locally caught fish 

IRs for some populations (e.g., Native Americans, Asian and Pacific Island communities, rural 

African American communities). Because consumption of locally caught fish varies substantially 

from region to region in the United States and from one population or ethnic group to the next, 

users of MIRC are encouraged to use more locally relevant data whenever available. 

For children ages 3 to 17 years and for adults, MIRC includes values for the mean and the 90th, 

95th, and 99th percentile fish ingestion rates (freshwater and estuarine fish only) based on EPA’s 

analysis of 1994-96 and 1998 Continuing Survey of Food Intakes by Individuals (CSFII) (EPA 

2002, 2008), part of USDA’s NFCS. Due to limitations of the available data, ICF analyzed the 

survey data to estimate child fish ingestion rates. The details of ICF’s approach are presented in 

EPA (2009). Table C-5 presents the age-specific mean and 90th percentile fish ingestion rates, 

which were used for the recreational angler scenario of the multipathway assessment for secondary 

lead smelting. 

Table C-5. 90th Percentile and Mean Fish Ingestion Rates 

Product Age Group 

Units g Child < 1 

Year 

Child 1-2 

Years 

Child 3-5 

Years 

Child 6-11 

Years 

Child 12-

19 Years 

Adult 20 - 

70 years 

Mean g/day NA a 1.37 2.03 2.71 3.9 6.9 

90th Percentile g/day NA a 3.24 4.79 6.9 8.95 17 

Source: EPA 2002 

a

 Infants are assumed to consume only breast milk for one year. 

MIRC also includes values for the mean and the 90th percentile fish ingestion rates for 

recreational anglers of Hispanic, Laotian, and Vietnamese descent. These populations are 
4/28/2011 C-7 

culturally or economically disposed to higher rates of fish ingestion than the general population. 

The fish ingestion rates for these populations, which are shown in Table C-6, were derived from 

a study by Shilling et al. (2010) of contaminated fish consumption in California’s Central Valley 

Delta. Shilling et al. (2010) reported mean and 95th percentile ingestion rates for each 

subpopulation. In part due to the low sample size (n of 30 to 45), 95th percentile values were 

believed to be unrealistically high. The 90th percentile ingestion rate estimates presented in 

Table C-6 were derived by EPA using information from Shilling et al. (2010). 

Table C-1. Calculated Mean and 90th Percentile Per capita Fish 

Ingestion Rates for Select Populations of Recreational Fishers (IRPC,y) 

Percentile Units Hispanic Recreational Fisher Laotia

n 

Recre

ationa

l 

Fisher 

Vietna

mese 

Recre

ationa

l 

Fisher 

Meana g/day 25.8 47.2 27.1 

90th 

Percentileb

g/day 98 144.8 99.1 

a

 Shilling et al. (2010) b

 EPA (2010)

C-4.5 Breast Milk Ingestion 

The breast milk ingestion rates (in kg/day) assumed for nursing infants are presented in Table 

C-7. These values were calculated using the EPA-recommended upper percentile breast milk 

ingestion rate for infants nursing up to one year of 980 mL/day (EPA 1997b) and the density of 

human milk (1.03 g/mL). 

Table C-7. Breast Milk Ingestion Rates for 

Infants Less Than 1 Year of Age

Percentile Breast Milk Ingestion Rate 

(kg/day) 

Mean 0.70864 

90th Percentile 1.0094 

The mean ingestion rate was calculated by multiplying the EPA-recommended mean breast milk 

ingestion rate for infants nursing up to one year of 688 mL/day (EPA 1997b, Table 14-16) by the 

density of human milk (1.03 g/mL) and converting to kg/day, for a final value of 0.70864 kg/day. 

The 90th percentile ingestion rate was calculated by multiplying the EPA-recommended upper 

percentile breast milk ingestion rate for infants nursing up to one year of 980 mL/day (EPA 

1997b, Table 14-16) by the density of human milk (1.03 g/mL) and converting to kg/day, for a 

final value of 1.0094 kg/day. As the units suggest, the ingestion rates for breast milk (kg/day) 

are not normalized for body weight. 

The magnitude of an infant’s exposure through ingestion of breast milk also depends on the 

mother’s exposure. The mother’s exposure can be calculated and varied in MIRC using the 

exposure factors detailed in the section, for instance, to utilize the mean or 90th percentile FFC 

ingestion rates. MIRC uses these data exposure factor assumptions in conjunction with 

adapted exposure algorithms and default assumptions from EPA’s Methodology for Assessing 
4/28/2011 C-8 

Health Risks Associated with Multiple Pathways of Exposure to Combustor Emissions (EPA 

1998) to calculate the infant’s average daily dose. 

C-5 Exposure Frequency 

The exposure frequency (EF) represents the number of days per year that an individual 

consumes home-produced food items that are contaminated with the chemical being assessed. 

In MIRC, the default value for EF is 365 days/year for all exposure sources and all potential 

receptors. This assumption is consistent with the food ingestion rates used in MIRC (i.e., daily 

intake rates equivalent to annual totals divided by 365 days) and does not imply that residents 

necessarily consume home-produced food products every day of the year. 

If the user wishes to evaluate daily intake rates based on shorter averaging times, the user can 

overwrite both the food-specific ingestion rates and the EF for each home-grown food product. 

Users of MIRC might want to specify lower EF values for various food types where residents 

obtain some of their diet from commercial sources and where consumption of home grown 

produce is seasonal. 

C-6 Fraction Contaminated 

The fraction contaminated (FC) represents the fraction of each food product consumed that is 

contaminated by the chemical at a level consistent with environmental concentrations in the 

area of concern (e.g., area with maximum deposition rates). Obviously, the most conservative 

assumption is that all food products consumed (i.e., 100 percent) are from the location 

represented by the chemical concentrations input into MIRC. 

For non-infant children and the adult age cohorts, MIRC includes the default FC of 1, assuming 

that 100 percent of the food product consumed is produced by households that farm, garden, or 

raise animals. The user can vary this default FC value for individual food products to tailor the 

assessment to a particular exposure scenario. 

C-7 Cooking Loss 

Cooking loss (CL) inputs are included to simulate the amount of a food product that is not 

ingested due to loss during preparation. 

Three distinct types of preparation and cooking losses are included in the ingestion exposure 

algorithms in MIRC: (1) loss of parts of the food type from paring (i.e., removing the skin from 

vegetables and fruits) or other types of preparation (e.g., removing pits, coring, deboning), (2) 

additional loss of weight for the food type during cooking (e.g., evaporation of water), and (3) 

post-cooking losses (e.g., non-consumption of bones, draining cooking liquid [e.g., spinach]). 

MIRC includes mean values for these three types of preparation and cooking losses for 

exposed fruit, protected fruit, exposed vegetables, protected vegetables, root vegetables, beef, 

pork, poultry, and fish. Different types of losses apply to different types of foods. Therefore, the 

losses can be represented by only two parameters, L1 and L2, the definitions of which vary 

according to the food type as explained in the endnotes in Table C-8. All preparation and 

cooking loss parameter values were estimated as specified in the Table’s endnotes from data 

presented in Chapter 13 of the EFH (EPA 1997a). 
4/28/2011 C-9 

Table C-8. Fraction Weight Losses from Preparation of Various Foods

Product 

Mean Cooking, Paring, or 

Preparation Loss 

(Cooking Loss Type 1 [L1]) 

 (unitless) a

Mean Net Post Cooking 

(Cooking Loss Type 2 [L2]) 

 (unitless) b

Exposed Fruit c 0.244 0.305 

Exposed Vegetable 0.162 d NA 

Protected Fruit 0.29 e NA 

Protected Vegetable 0.088 f NA 

Root Vegetable g 0.075 0.22 

Beef 0.27 0.24 

Pork 0.28 0.36 

Poultry 0.32 0.295 h

Fish i 0.0j 0.0 

Source: EPA 1997a (Chapter 13; Tables 13-5 [meats], 13-6 [fruits], and 13-7 [vegetables]) 

NA = Not Available 

a

 For fruits, includes losses from draining cooked forms. For vegetables, includes losses due to paring, trimming, 

flowering the stalk, thawing, draining, scraping, shelling, slicing, husking, chopping, and dicing and gains from the 

addition of water, fat, or other ingredients. For meats, includes dripping and volatile losses during cooking. b

 For fruits, includes losses from removal of skin or peel, core or pit, stems or caps, seeds and defects; may also 

include losses from removal of drained liquids from canned or frozen forms. For vegetables, includes losses from 

draining or removal of skin. For meats, includes losses from cutting, shrinkage, excess fat, bones, scraps, and 

juices. 

c

 These values represent averages of means for all fruits with available data (except oranges) (Table 13-6). d

 This value represents an average of means for all exposed vegetables with available data (Table 13-7). Exposed 

vegetables include asparagus, broccoli, cabbage, cucumber, lettuce, okra, peppers, snap beans, and tomatoes. e

 This value was set equal to the value for oranges (Table 13-6). 

f

 This value represents an average of means for all protected vegetables with available data (Table 13-7). 

Protected vegetables include pumpkin, corn, peas, and lima beans. 

g

 These values represent averages of means for all root vegetables with available data (Table 13-7). Root 

vegetables include beets, carrots, onions, and potatoes. h

 This value represents an average of means for chicken and turkey (Table 13-5). 

i If the user changes fish ingestion rates to match a survey of the whole weight of fish brought into the home from 

the field (divided by the consumers of the fish), an appropriate value for L1 would be 0.3 (EPA 1997a, Table 13-5). 

For volatile or water soluble chemicals, a non-zero value for L2 also may be appropriate. Although EPA (1997a) 

recommended 0.11 for L2, it varies substantially by chemical. 

J

In the case of methyl mercury in fish, a cooking correction factor (CCF) is used rather than an L1 loss to account 

for concentration of methyl mercury in fish during cooking as water is volatilized, reducing the fish weight, but 

mercury is not. 
4/28/2011 C-10 

C-8 References 

Morgan, J., R. Berry and R. Graves. 1997. Effects of commonly used cooking practices on the 

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