### SHEDS **- HT Supplemental Material**  A. SHEDS
- HT Code
................................ ................................ ................................ ................................ .. 1 B. Input Files
................................ ................................ ................................ ................................ ............. 2 C. Output File s ................................ ................................ ................................ ................................ ......... 10 D. Running the SHEDS
- HT Case Study for the U.S. Population
................................ ............................ 10 E. SHEDS
- HT Equations
................................ ................................ ................................ ........................ 12 a. Residential Media Concentrations: Reduced SHEDS
- Fugacity Model
................................ .......... 12 b. Direct Pathway Exposure Methods
................................ ................................ ................................ . 18 c. Indirect Pathway Methods: Indirect Exposure Equatio ns ................................ ............................... 19 d. Dietary Exposure Methods
................................ ................................ ................................ .............. 20 e. Total Chemical Exposures by Route
................................ ................................ ............................... 21 f. Dermal Removal Processes
................................ ................................ ................................ ............. 21 g. Absorption Rates: Intake Dose Estimates
................................ ................................ ....................... 23 F. References
................................ ................................ ................................ ................................ ........... 23 G. Attachments
................................ ................................ ................................ ................................ ........ 23


### A. **SHEDS -**  **HT Code**  The SHEDS
- HT Code is written in R , and is included as an attachment . The following packages, with their dependencies, must be downloaded and installed:

 data.table (http://cran.r
-project.org/web/packages/data.table/index.html )  gdata (http://cran.r
-project.org/web/packages/gdata/index.html )  plyr (http://cran.r
-project.org/web/packages/plyr/index.html )  ggplot2 (http://cran .r -project.org/web/packages/ggplot2 /index.html The code subroutines are included in 6 source files:
 ShedsHT.R: setup and main exposure routines  Readdata.R: subroutines for reading SHEDS
- HT input files  Distributions.R: subroutines for generating random samples from various probability distributions  Summarize.R: output file generation  RunScenarios.R: subroutines for running SHEDS
- HT from the batch scenarios file or for a single chemical  Fugacity.R: subroutines for generating residential media concentrations using a reduced fugacity
based source
-to - concentration module. The SHEDS
- HT file structure is as follows (where ... is the installation directory):

 .../R/ SHEDS
- HT code R files  .../Inputs/ SHEDS
- HT Input files  .../Output/ Location where output exposure files are written

### B. **Input Files** The SHEDS
- HT Input files an d their contents are as follows. All SHEDS
- HT default and cas e study input files are included in the attachments.
 **Physiological Parameters File (.../Inputs/bwsa.csv)** Contains regression data for body weight, height, and basal metabolic rate as functions of age and gender. This file has been used with other SHEDS mo dels including SHEDS
- Multimedia.

 **Diaries File (.../Inputs/diaries.csv)**  Contains a summary of the activity diaries from the C onsolidated Human A ctivity Database (CHAD) . Each record represents one 24
- hour person
day of data, with indicator variables for the age, gender, season, and weekday. The times (in minutes) in each of the SHEDS
- HT microenvironments is given, along with the mean metabolic equivalent ( METS , a multiple of basal metabolic rate) value in each microenvironment , based on the CHAD activity codes. The “bath” column indicates the time spent in a bath or shower, if this was recorded.

 **Diet Diaries File**  **(.../Inputs/ diet_diaries**  **.csv)** Summary of food consumption data from the NHANES
- What We Eat In America Study (1999
- 2006). Food consumption in g is g iven for each of the SHEDS
- HT default food groups (Table S3) for each person in the study.

 **Microenvironments File**  **(.../Inputs/ micros**  **.csv)** This small file contains a list of the micro environments in SHEDS
- HT, along with short descriptions of each. There is no reason to change this file, unless the user wanted to define new microenvironments . That would have several consequences. In particular, the Diaries file would need to be compatible with the new microenvironments by indicating the time spent in each.

 **Media File (.../ Inputs/** **media .csv)**  Contains contact probabilities for media ( e.g. air , surfaces , and pet) in each microenvironment. The contact probability (contact.p) is the fraction of time spent in that micro in contact with that medium, and must be between zero and one, inclusive.

 **Population File (.../Inputs/** **pop2000 .csv)**  This file contains counts of males and females of each year of age from 0 to 99, from the 2000 U.S. census. These are used to generate probabilities for each age
- gender combination. If the user is modeling a distinctive population subgroup, then this file sho uld be altered or replaced with the appropriate modifications.

 **Exposure Factors File (.../Inputs/ ExpFactors.csv)** Contains default SHEDS
- HT exposure factor distributions. Data sources and variables are provided in the main Exposure SAP White P aper.

 **Fugacit y Inputs File (.../Inputs/Fugacity.csv)**  Contains input parameter distributions for the SHEDS
- HT fugacity module. Default values are given in Table S1.

 **Chemicals File (.../Inputs/chemprops.csv)** EPI
- Suite derived chemical properties for over 144000 environmental chemicals.

###  **Scenarios file (.../Inputs/Scenarios.csv)** Can be thought of as the main SHEDS
- HT input file, that allows the model to generate HT aggregate exposure estimates. This file contains a structured listing of all exposure scenarios to be modeled, by chemical, and the input parameters required to parameterize the corresponding exposure equations (given in Section E). The scenarios are parameterized by consumer product category or food/eater group as appropriate. Default SHEDS
- HT consumer product categories are given in Table S2; default food groups are given in Table S 3
. Consumer product use parameters for the initial SHEDS
- HT case study (the included scenarios.csv) were determined from available data sources (including default values us ed by other screening
- level models) or assumed using best judgment. The chemical composition data used in the case study was obtained from two existing databases of chemical ingredients in consumer products. The first database was EPA’s Consumer Product Chemical Profile Database (CPCPdb , Goldsmith et al. 201 4 )
. This database contains information on 1797 chemicals found in 8921 consumer products derived from retailer
-provided material safety data sheets (MSDS). The second database was the National Library o f Medicine’s Ho usehold Products Database (NLM) which is also based on collated MSDS data . Food and water residue distributions were derived from the Pesticide Data Program Databases for 1997
- 2011 (USDA). The currently available exposure scenarios and a summary of their required input parameter distributions are:
o **DIRDERM :**  Direct dermal (parameterized by chemical and consumer product category)  Composition (chemical mass percent)  Frequency of use (1/year)  Fraction of population using product  Mass of product used (g)  Duration of product use (min)  Fraction of mass in contact with skin  Fraction of residual mass retained on skin after use
o **DIRINHVAP :**  Direct dermal inhalation of vapor (parameterized by chemical and consumer product category)  Composition (chemical mass percent)  Frequency of use (1/year)  Fraction of population using product  Mass of product used (g)  Duration of product use (min)
o **DIRINHAER :**  Direct dermal inhalation of aerosol mass(parameterized by chemical and consumer product category)  Composition (c hemical mass percent)  Frequency of use (1/year)  Fraction of population using product  Mass of product used (g)  Duration of product use (min)
o **DIRINGEST :**  Direct incidental ingestion (parameterized by chemical and consumer product category)

###  Composition (chemi cal mass percent)  Frequency of use (1/year)  Fraction of population using product  Mass of product used (g)  Duration of product use (min)  Fraction of mass used that is ingested
o **INDIRECT :**  Post
- application indirect exposure via inhaling contaminated air or touching contaminated surfaces (parameterized by chemical and consumer product category)  Composition (chemical mass percent)  Frequency of use (1/year)  Fraction of population using product  Mass of product used (g)
o **DIETARY :**  Ingestion via residue in food or drinking water (parameterized by chemical and food/water group)  Number of zero and non
- zero measurements for food groups  Residue (concentration, μg /g) distribution for group Table S1. Input variables for the fugacity module of SHEDS
- HT. **Variable Nam**  **e Description**  **Units Value in SHEDS** 
AER o air exchange rate for rooms with

outdoors 1/d Lognormal(11.9, 1.7) MA sf chemical mass applied to surfaces at t=0 g/m 2 Determined from category
- specific use patterns MA a chemical mass applied to air at t=0 μg/m 3 Assumed to be 0 for indirect pathways H height of walls m Uniform(2.44,3) Assumed A f total floor area of the house m 2 Lognormal(130, 1.8) C out chemical concentration in outdoor air μg/m 3 Assumed to be 0 as default CI ,a prior chemical concentration in air μg/m 3 Assumed to be 0 as default CI, sf prior chemical concentration on surfaces μg/cm 2 Assumed to be 0 as default CS a chemical emission rate (source strength)

in air μg/m 3 /d ay User supplied; not used in current case study CS sf chemical emission rate (source strength)

in surfaces μg/m 2/d ay User supplied; not used in current case study D a chemical decay rate constant in air 1/d Determined from EPI Suite D sf chemical decay rate constant on surfaces 1/d Determined from EPI Suite half
- lives as described in main manuscript DC a diffusion coefficient in air m 2/d Determined from EPI Suite K ow octanol
- water partition coefficient
- Determined from EPI Suite VP vapor pressure Pa Determined from EPI Suite Sol solubility mol/ m 3 Determined from EPI Suite MW molecular weight g/mol Determined from EPI Suite CF s organic carbon fraction for small

particles
- Normal (0.3,0.03) CF l organic carbon fraction for large particles
- Normal (0.15,0.01) CL a,s cleaning removal rate for small particles

in air 1/d Uniform (0.018, 0.22 ) CL a,l cleaning removal rate for large particles 1/d Uniform ( 0.03 , 0.5 )**Variable Nam**  **e Description**  **Units Value in SHEDS** 

in air CL sf,s cleaning removal rate for small particles

on surfaces 1/d Uniform (0.035, 0.45 ) CL sf,l cleaning removal rate for large particles

on surfaces 1/d Uniform (0.035, 0.045 ) PD a,s air
- to - floor small particle deposition rate m/d Normal (11,1) PD a,l air
- to - floor large particle deposition rate m/d Normal (387,20) T indoor temperature K Normal (296,2) TH b boundary layer thickness over surfaces m Uniform (0.025,0.0275) TH sf effective thickness of surfaces m Normal (0.0098, 0.002 ) R sf,s surface
- to - air small particle resuspension

rate 1/d Normal (0.00072, 0.00082 ) R sf,l surface
- to - air large particle resuspension

rate 1/d Normal (0.0015, 0.0017 ) L a,s loading of small particles in air μg/m 3 Uniform (15, 2 5 ) L a,l loading of large particles in air μg/m 3 Uniform (2.2, 2.5 ) L sf,s loading of small particles on surfaces μg/cm 2 Uniform (6, 14.5 ) L sf,l loading of large particles on surfaces μg/cm 2 Uniform (11.5, 28 )



### Table S2. SHEDS
- HT D efault Consumer Product Categories.

**Product Category** ARTS AND CRAFTS; ARTS AND CRAFTS FINISH ARTS AND CRAFTS; ARTS AND CRAFTS FINISH, SPRAY ARTS AND CRAFTS; ARTS AND CRAFTS FRAGRANCES ARTS AND CRAFTS; ARTS AND CRAFTS PAINT ARTS AND CRAFTS; ARTS AND CRAFTS PAINT THINNER ARTS AND CRAFTS; ARTS AND CRAFTS PAINT, EXTERIOR ARTS AND CRAFTS; ARTS AND CRAFTS PAINT, SPRAY ARTS AND CRAFTS; ARTS AND CRAFTS SEALANT ARTS AND CRAFTS; BIKE TIRE SEALER ARTS AND CRAFTS; BODY PAINT ARTS AND CRAFTS; CANDLE
- MAKING ARTS AND CRAFTS; CERAMICS ARTS AND CRAFTS; DYE ARTS AND CRAFTS; FABRIC PAINTS AND SEALERS ARTS AND CRAFTS; FINGER PAINT ARTS AND CRAFTS; FIXATIVE ARTS AND CRAFTS; FLOCKING ARTS AND CRAFTS; FOGGER ARTS AND CRAFTS; GESSO ARTS AND CRAFTS; GLASS ETCHING/POLISHING ARTS AND CRAFTS; GLAZE ARTS AND CRAFTS; MODEL ENGINE FUEL ARTS AND CRAFTS; MODEL PAINT ARTS AND CRAFTS; OIL PAINT ARTS AND CRAFTS; PENS AND MARKERS ARTS AND CRAFTS; SOAP
- MAKING AUTO PRODUCTS; ANTIFREEZE AUTO PRODUCTS; AUTO AIR FRESHENER AUTO PRODUCTS; AUTO DEGREASER AUTO PRODUCTS; AUTO FLUIDS AND ADDITIVES AUTO PRODUCTS; AUTO LUBRICA NT AUTO PRODUCTS; AUTO PAINT AUTO PRODUCTS; AUTO REFRIGERANT**Product Category** AUTO PRODUCTS; BOAT CLEANER AUTO PRODUCTS; BOAT ENGINE FLUIDS AUTO PRODUCTS; BOAT PAINT AUTO PRODUCTS; BODY REPAIR AUTO PRODUCTS; BODY WASH OR WAX AUTO PRODUCTS; DETAILING AUTO PRODUCTS; MOTOR OIL AUTO PRODUCTS; TIRE REPAIR AUTO PRODUCTS; WHEELS AUTO PRODUCTS; WINDOWS/WINDSHIELD HOME MAINTENANCE; ADHESIVE HOME MAINTENANCE; ADHESIVE REMOVER HOME MAINTENANCE; ADHESIVE, EXTERIOR HOME MAINTENANCE; BLEACHING OIL HOME MAINTENANCE; CAULK REMOVER HOME MAINTENANCE; CAULK/SEALANT HOME MAINTENANCE; CAULK/SEALANT, EXTERIOR HOME MAINTENANCE; CONCRETE HOME MAINTENANCE; CONCRETE ADDITIVE HOME MAINTENANCE; CORROSION PROTECTION HOME MAINTENANCE; DEGREASER HOME MAINTENANCE; DRYWALL RETARDER HOME MAINTENANCE; ELECTRONICS LUBRICANT HOME MAINTENANCE; FINISH HOME MAINTENANCE; FINISH GLAZE HOME MAINTENANCE; FINISH HARDENER HOME MAINTENANCE; FINISH, SPRAY HOME MAINTENANCE; FINISH, EXTERIOR HOME MAINTENANCE; GLAZING HOME MAINTENANCE; GROUT ADDITIVE HOME MAINTENANCE; GROUT HAZE REMOVER HOME MAINTENANCE; GROUT SEALER HOME MAINTENANCE; HOME MAINTENANCE CLEANER HOME MAINTENANCE; JOINT COMPOUND HOME MAINTENANCE; LACQUER HOME MAINTENANCE; LOCK DEICER HOME MAINTENANCE; LUBRICANT HOME MAINTENANCE; MORTAR OR GROUT HOME MAINTENANCE; MULTIPURPOSE ADHESIVE HOME MAINTENANCE; PAINT HOME MAINTENANCE; PAINT ADDITIVE HOME MAINTENANCE; PAINT CLEANER HOME MAINTENANCE; PAINT TEXTURE HOME MAINTENANCE; PAINT THINNER HOME MAINTENANCE; PAINT, EXTERIOR HOME MAINTENANCE; PAINT, INTERIOR HOME MAINTENANCE; PAINT, SPRAY HOME MAINTENANCE; PATCH AND REPAIR HOME MAINTENANCE; PLASTER HOME MAINTENANCE; PLUMBING HOME MAINTENANCE; PORCELAIN HOME MAINTENANCE; PRESTAIN PRODUCTS HOME MAINTENANCE; PRIMER HOME MAINTENANCE; PRIMER, EXTERIOR HOME MAINTENANCE; PRIMER, INTERIOR HOME MAINTENANCE; PRIMER, SPRAY HOME MAINTENANCE; PUTTY OR FILLER HOME MAINTENANCE; REFRIGERANT HOME MAINTENANCE; ROOF HOME MAINTENANCE; SEALANT HOME MAINTENANCE; SOLDER**Product Category** HOME MAINTENANCE; SPRAY FOAM HOME MAINTENANCE; STAIN HOME MAINTENANCE; STAIN, EXTERIOR HOME MAINTENANCE; STAIN, SPRAY HOME MAINTENANCE; STRIPPER HOME MAINTENANCE; STRIPPER, EXTERIOR HOME MAINTENANCE; STUCCO REPAIR HOME MAINTENANCE; SUPER GLUE HOME MAINTENANCE; SURFACE SEALER HOME MAINTENANCE; SURFACE SEALER, EXTERIOR HOME MAINTENANCE; WELDING HOME MAINTENANCE; WOOD ADHESIVE HOME MAINTENANCE; WOOD PRESERVATIVE HOME OFFICE; PRINTER INK/TONER HOME OFFICE; WHITE OUT INSIDE THE HOME; AIR FRESHENER INSIDE THE HOME; ANTI
- STATIC SPRAY INSIDE THE HOME; AUTOMATIC DISHWASHING INSIDE THE HOME; AUTOMATIC DISHWASHING ADDITIVE INSIDE THE HOME; AUTOMATIC DISHWASHING DETERGENT INSIDE THE HOME; BATHROOM CLEANER INSIDE THE HOME; BLEACH INSIDE THE HOME; CARPET CLEANER INSIDE THE HOME; CARPET DEODORIZER INSIDE THE HOME; CLEANER INSIDE THE HOME; DISH SOAP INSIDE THE HOME; DISINFECTANT INSIDE THE HOME; DISINFECTANT, SPRAY INSIDE THE HOME; DRAIN INSIDE THE HOME; DRY CLEANER INSIDE THE HOME; ELECTRONIC S CLEANER INSIDE THE HOME; FABRIC DEODORIZER INSIDE THE HOME; FABRIC PROTECTANT INSIDE THE HOME; FABRIC SOFTENER INSIDE THE HOME; FIREPLACE INSIDE THE HOME; FLOOR CLEANER INSIDE THE HOME; FLOOR POLISH INSIDE THE HOME; FLOOR SEALER INSIDE THE HOME; FURNITURE WAX INSIDE THE HOME; GARBAGE DISPOSAL DEODORIZER INSIDE THE HOME; GLASS CLEANER INSIDE THE HOME; GROUT CLEANER INSIDE THE HOME; GUM REMOVER INSIDE THE HOME; HAND CLEANER INSIDE THE HOME; HOUSEPLANT CARE INSIDE THE HOME; LAMP OIL/LIGHTER FLUID INSIDE THE HOME; LAUNDRY DETERGENT INSIDE THE HOME; LAUNDRY STAIN REMOVER INSIDE THE HOME; LAUNDRY STARCH INSIDE THE HOME; LEATHER CLEANER INSIDE THE HOME; LIME REMOVER INSIDE THE HOME; METAL POLISH INSIDE THE HOME; OVEN CLEANER INSIDE THE HOME; PRODUCE CLEANER INSIDE THE HOME; SHOE POLISH OR PROTECTANT INSIDE THE HOME; SILVER CLEANER INSIDE THE HOME; STARCH INSIDE THE HOME; SURFACE CLEANER INSIDE THE HOME; UPHOLSTERY CLEANER INSIDE THE HOME; WASHING MACHINE CLEANER INSIDE THE HOME; WAX REMOVER**Product Category** INSIDE THE HOME; WOOD POLISH LANDSCAPE/YARD; BUBBLE SOLUTION LANDSCAPE/YARD; CLEANER, EXTERIOR LANDSCAPE/YARD; COMPOST LANDSCAPE/YARD; COMPOST TREATMENTS LANDSCAPE/YARD; FERTILIZER LANDSCAPE/YARD; GARDEN CARE, OTHER LANDSCAPE/YARD; GARD EN FERTILIZER LANDSCAPE/YARD; GRILL/CAMPING FUEL LANDSCAPE/YARD; HERBICIDE LANDSCAPE/YARD; HOT TUB/SPA CHEMICALS LANDSCAPE/YARD; HUMUS LANDSCAPE/YARD; LAWN CARE, OTHER LANDSCAPE/YARD; LAWN FERTILIZER LANDSCAPE/YARD; LAWN FUNGICIDE LANDSCAPE/YARD; LAWN SEED LANDSCAPE/YARD; LAWNMOWER FLUIDS LANDSCAPE/YARD; MULCH LANDSCAPE/YARD; POND TREATMENTS LANDSCAPE/YARD; POOL CHEMICALS LANDSCAPE/YARD; POTTING SOIL LANDSCAPE/YARD; SKUNK ODOR REMOVER LANDSCAPE/YARD; SURFACE DEICER LANDSCAPE/YARD; TOOL LUBRICANT LANDSCAPE/YARD; TOPSOIL LANDSCAPE/YARD; TREES PERSONAL CARE; AFTERSHAVE PERSONAL CARE; BABY CONDITIONER PERSONAL CARE; BABY LOTION PERSONAL CARE; BABY OIL PERSONAL CARE; BABY POWDER PERSONAL CARE; BABY SHAMPOO PERSONAL CARE; BABY WASH PERSONAL CARE; BABY WIPES PERSONAL CARE; BAR SOAP PERSONAL CARE; BATH OIL/SALTS PERSONAL CARE; BODY HAIR BLEACH PERSONAL CARE; BODY LOTION PERSONAL CARE; BODY MAKEUP PERSONAL CARE; BODY POWDER PERSONAL CARE; BODY WASH PERSONAL CARE; BODY WIPES PERSONAL CARE; BUBBLE BATH PERSONAL CARE; CLIPPER LUBRICANT PERSONAL CARE; CONDITIONER PERSONAL CARE; CONTACT CARE PERSONAL CARE; DENTURE PRODUCTS PERSONAL CARE; DEODORANT PERSONAL CARE; DEPILATORY PERSONAL CARE; DIAPER CREAM PERSONAL CARE; EYE MAKEUP PERSONAL CARE; EYE PRODUCTS, OTHER PERSONAL CARE; FACE CREAM PERSONAL CARE; FACE MAKEUP PERSONAL CARE; FACE WASH PERSONAL CARE; FOOT CARE PERSONAL CARE; FRAGRANCES PERSONAL CARE; HAIR COLOR PERSONAL CARE; HAIR RELAXER PERSONAL CARE; HAIR SPRAY PERSONAL CARE; HAIR STYLING**Product Category** PERSONAL CARE; HAND LOTION PERSONAL CARE; HAND SANITIZER PERSONAL CARE; HAND SOAP PERSONAL CARE; JEWELRY CLEANER PERSONAL CARE; KID'S FRAGRANCE PERSONAL CARE; LICE SHAMPOO PERSONAL CARE; LINIMENT PERSONAL CARE; LIPS PERSONAL CARE; MOUTHWASH PERSONAL CARE; NAIL ADHESIVE PERSONAL CARE; NAIL POLISH PERSONAL CARE; NAIL POLISH REMOVER PERSONAL CARE; SCALP TREATMENTS PERSONAL CARE; SELF TANNER PERSONAL CARE; SEXUAL WELLNESS PERSONAL CARE; SHAMPOO PERSONAL CARE; SHAVING CREAM PERSONAL CARE; SUNSCREEN PERSONAL CARE; TEETH WHITENER PERSONAL CARE; TONER PERSONAL CARE; TOOTHPASTE PESTICIDES; ANIMAL REPELLENT PESTICIDES; FUNGICIDE PESTICIDES; INSECT REPELLENT PESTICIDES; INSECT REPELLENT, EXTERIOR PESTICIDES; INSECT REPELLENT, SKIN PESTICIDES; INSECTICIDE PESTICIDES; INSECTICIDE, EXTERIOR PESTICIDES; INSECTICIDE, INTERIOR PESTICIDES; RODENTICIDE PET CARE; AQUARIUM PET CARE; CAT LITTER PET CARE; OTHER PET TREATMENTS PET CARE; PESTICIDE, PET PET CARE; PET SHAMPOO PET CARE; SPOT CLEANER 

### Table S3. SHEDS
- HT default food groups (crop groups).

**Crop Group Label in SHEDS Crop Group Description** 

AS Asparagus BA Banana BF Beef BR Brassica (Cole) Leafy Vegetables BS Berry and Small Fruit BV Bulb Vegetables CF Citrus Fruits CG Cereal Grains CH Chicken CV Cucurbit Vegetables DP Dairy Products DW Drinking Water (Direct, Indirect) EF Edible Fungi EG Egg FI Fish FV Fruiting Vegetables (except cucurbits) GO Goat HM Human milk**Crop Group Label in SHEDS Crop Group Description**  HO Honey HS Herbs and Spices LE Leafy Vegetables (except Brassica vegetables) LR Leaves of Root and Tuber Vegetables LV Legume Vegetables (Succulent or dried) MA Mango MG Meat, game NA Nongrass Animal Feeds (Forage, Fodder, Straw and Hay) * OS Oilseeds OT Other PA Papaya PE Peanut PF Pome Fruits PI Pineapple PO Poultry, Other PR Pork RA Rabbit RS Raisins RT Root and Tuber Vegetables SF Stone Fruits SH Sheep TN Tree Nuts TU Turkey *Alfalfa is only food commodity in this group 

### C. **Output Files** The SHEDS
- HT output files contain aggregate exposure percentiles (and mean/standard deviations) , by route, for each chemical in the model run (each chemical is written to its own file). The variables included in the file are:

 exp.d ermal: Total dermal exposure via direct and indirect scenarios ( μg/day)  exp.ingest : Total ingestion exposure via direct and dietary scenarios ( μg/day)  exp.inhal : Total inhal ation exposure via direct and indirect scenarios ( μg/m3 

### )  dose.intake : Intake dose via inhalation, dermal, and ingestion pathways (mg/kg/day)  abs.dermal.ug : Dermally absorbed dose ( μg)  abs.inhal.ug : Inhaled absorbed dose ( μg)  abs.ingest.ug : Ingested absorbed dose ( μg)  abs.tot.ug : Total absorbed dose ( μg)  abs.tot.mgkg : Total absorbed dose (mg/kg/day) 

### D. **Running the SHEDS**  **- HT Case Study for the U.S. Population**  Included as attachments are the SHEDS
- HT input files required to run a case study of over 2500 chemicals found in consumer products and foods. This section contains a brief descriptions of the steps required to r

un this case study for the US Population (all ages and genders)
. 1) Install R (and RStudio, if desired). Download and install the required R packages and dependencies. This is done easily by running the install.packages command from R, for example , install.packages (“plyr”)
.

### 2) Download the SHEDS
- HT direc tories (R, Inputs, and Out as described in Section A) to a local directory. The local directory can have any name, but for convenience will be called SHEDSHome here. 3) Open the main SHEDS
- HT module, SHEDSHT.R. Edi t the argument of the “setup” to designate the location of the working directory to be the path of SHEDSHome. Note that the slashes must be forward slashes. 4) Source SHEDSHT.R (In RStudio, Code
- >Source, or use the “Source” button). 5) Run setup (In RStudio, b y typing “setup()”at the prompt. This loads the required packages for the current R session and sources all the SHEDS
- HT R code. 6) Run SHEDS
- HT for all exposure scenarios in the case study scenarios file by typing runScenarios(size=N, runName=”Name”) where N is the number of individuals to simulate and “Name” is an identifier that will be appended to each output file. For example, to run a 10,000
- individual run called Base, type runScenarios(size=10000, runName=”Base”) (note run name must be in quotes). Th e output results included in the attachment (runName “test”) are for a relatively small run of the case study for 1000 individuals. The first several minutes of the run will be set time, wherein data files are read, and simulated people are created. Then, SHEDS
- HT will begin to march through the scenarios file, calculating population aggregate exposures for each chemical (they are index by CASRN) and writing the resulting summary statistics to output files. Progress is written to the R Console. The Output files are written to the SHEDSHome/Out directory. Each output file is named output_CASRN_Name where “Name” is the runName given in the runScenarios call. SHEDS
- HT does n ot currently contain tools for loading data for all chemicals and performing visual izations or analyses; this must be done by the user outside of the program. The SHEDS
- HT case study can be run with other settings (e.g. different age/gender groups) by updating the settings in the **getScenSpecs** subroutine in ReadData.R, sourcing that file, and calling runScenarios again. Future versions of the code will have the ability to update these parameters in a more convenient manner. Some key settings that can be changed are:
 **runSeed** This is a number from 1 to 2147483647, used as the initial random number seed for the run. If output from two model runs for the same chemical is to be combined into a single data set, the runSeeds for the two runs should be different.  **minAge** The smalles t age to simulate. Must be an integer. Age=0 refers to all children under 12 months.  **maxAge** The maximum age to simulate. Must be an integer and cannot exceed 99. Centenarians are considered to remain age 99 indefinitely.  **Genders** One of “F”, “M”, or c(“F ”,”M”), for females, males, or both, respectively. The quotes are required. The c() function forms a list of strings.  **seasons** The seasons are “W” (winter: Dec, Jan, Feb), “P” (spring: Mar, Apr, May), “S” (summer: Ju n, Jul, Aug), and “F” (fall: Sep, Oct, Nov). If two or more seasons are to be modeled, combine them with the c() function. For example, seasons=c(“P”,”S”) for spring and summer, or seasons=c( “W”, ” P”,”S”,”F”) for all.  **ageMatchPct** This is the maximum percentage mismatch allowed in age when choo sing an activity diary. For example, if the simulated person is age 50 and ageMatchPct=10, then activity diaries from persons age 45 to 55 (inclusive) may potentially be selected. The window is rounded

### to the nearest integer at both ends. The greatest di fficulty is in matching the oldest persons. To always have suitable diaries available for all seasons, day types, and genders, using the default diary database, the minimum value is ageMatchPct=11. The default value is 15. For runs restricted to young people, there are many suitable diaries of the correct age, and is it possible to set ageMatchPct=0 to force an exact match. 

### E. **SHEDS -**  **HT Equations** 

**a. Residential Media Concentrations:**  **Reduced SHEDS -**  **Fugacity Model** The simplified , screening
- level, version of the SHEDS
- Fugacity model incorporated in SHEDS
- HT has just two compartments: air and floor. Subscripts for the two model compartments are “a” (air) and “sf” (surfaces). Subscripts for large and small particles are given as “l” and “s.” Variabl e names and definitions for the required inputs are given in in Section B . The equations are given below. **Particle Masses and Cleaning Rates**  Volume of air compartment (m3 

### ) : V a = A f ×	H (1) 

### Small and large particle masses in air (μg): MP a, s = V a ×	L a,s (2) MP a,l = V a ×	L a,l (3) 

### Small and large particle masses on surfaces (μg); 1E4 factor is for units conversion (cm 2 

### to m2 

### ): MP s f ,s = A f ×	1E4	×	L s f ,s (4) MP s f ,l = A f ×	1E4	×	L s f ,l (5) 

### Cleaning rates from surfaces for large and small particles (1/day). These are sampled from the input distributions, but then constrained to force particle mass balance as below: CL s f ,s ≥ PD a,s ×	L a,s /	(1E4	×	L s f ,s )
– R s f

,s (6) CL s f ,l ≥ PD a,l ×	L a,l /	(1E4	×	L s f ,l )
– R s f

,l (7) 

### Cleaning rates from air for large and small particles (1/day). These are sampled from the input distributions, but then constrained to force particle mass balance as below: CL ,a,s ≥ (R sf

,s × MP s f

,s - PD a,s × L a,s ×	A f

)/	MP a,s (8) CL ,a,l ≥ (R sf

,l × MP s f

,l - PD a,l × L a,l ×	A f

)/	MP a,l (9)

### Partition Coefficients Conversion factor between μg and moles (μg/mol): ugmol = 1E6 × MW (10) 

### Air/surface partition coefficient (derived from the mean of the expressions for vinyl and carpet from Bennett and Furtaw, 2004): K a

_ s f =	82500	×	VP
- 0.6 5 (11) 

### Air/particle partition coeffcient for small and large particles (m3 

### /μg), where the gas constant Rgas 

### = 8.314 Pa
- m 3 

### /(mol
- K):

Kp,s = 1
. 6625E
− 12 × K ow × Rgas × T × CF s VP (12)
Kp,l = 1
. 6625E
− 12 × K ow × Rgas × T × CF

VP (13) 

### Fugacity Capacities and Fugacity to Mass Ratios Fugacity capacity of air ([mol/(Pa m3 

### )]: Z a,b = × (14) 

### Fugacity capacity of bulk surface compartment ([mol/(Pa m3 

### )]: Z sf,b = K a_sf ×	Z a,b (15) 

### Ratio of mass to fugacity (ZV, in μg/Pa) for bulk (vapor phase) air: ZV a =		Z a,b ×	V a ×	ugmol (16) 

### Ratio of mass to fugacity (ZV, in μg/Pa) for surfaces: ZV s f,b =		Z s f,b ×	A f ×	TH sf ×	ugmol (17) 

### Ratio of mass to fugacity (ZV, in μg/Pa) for small and large particles in the air compartment: ZV a,s =	ZV a,b ×	Kp , s ×	L a,s (18) ZV a,l =	ZV a,b ×	Kp ,l	×	L a, l (19) 

### Unit capacities of large and small particles (fugacity capacity per unit mass, in 1/Pa): CP s =	Z a ×	Kp , s ×	ugmol	= 1
. 6625E
− 6 × MW × K ow × CF s × Sol VP (20)CP l =	Z a ×	Kp ,l	×	ugmol	= 1
. 6625E
− 6 × MW × K ow × CF l × Sol VP (21) 

### Ratio of mass to fugacity (ZV, in μg/Pa) for small and large particles in the surface compartment: ZV s f ,s =	CP s ×	MP s,s (22) ZV s f , l =	CP l ×	MP s,l (23) 

### Ratio of mass to fugacity (ZV, in μg/Pa) and fugacity to mass (iZV, Pa/ μg) for entire air compartment (sum of phase
- specific ZV): ZV a =	ZV a,b +	ZV a,s + ZV a,l (24) iZV a =	(ZV a,b +	ZV a,s + ZV a,l )
- 1 (25) 

### Ratio of mass to fugacity (ZV, in μg/Pa) and fugacity to mass (iZV, Pa/ μg) for entire surface compartment (sum of phase
- specific ZV): ZV sf =	ZV s,b +	ZV s,s + ZV s,l (26) iZV sf =	(ZV sf,b +	ZV sf,s + ZV sf,l )
- 1 (27) 

### Chemical Flows Given the chemical mass in the air compartment M a 

### and the surface compartment M s f 

### , chemical flow via small and large particles (μg/day) from the air compartment due to any process X, either deposition (PD) or cleaning (CL): QX,a,s =	M a ×	MP a, s ×	iZV a ×	CP s ×	X a,s (28) QX,a,l =	M a × MP a, l ×	iZV a ×	CP l ×	X a,l (29) 

### Chemical flow ( μg /day) to the air from the surface compartment is given by the following, where the process X is either resuspension (R) or cleaning (CL): QX,a,s =	M sf ×MP sf, s ×	iZV sf ×	CP s × X sf,s (30) QX,a,l =	M sf ×MP sf, s ×	iZV sf ×	CP l ×	X sf ,l (31) 

### Chemical flow (μg/day) due to bulk air movement is given by the following equations. Flow from air to outdoors: Q a_o,b =		M a ×	AER o (32) 

### Flow from outdoors to indoor air: Q o_a,b =		C out ×	AER o ×	V a (33)

### Transfer factors between air and surface (see Bennett and Furtaw, 2004) and diffusive flows from air to surfaces and surfaces to air: Ya

_ s f =		min	[DC a ×	Z a / TH b , 0.0135 ×	(VP)
- 0.3 2 ] (34) Q a_sf,df =		M a ×	A f ×	iZV a ×	ugmol	×	Y a_sf (35) Q sf_a,df =		M sf ×	A f ×	iZV sf ×	ugmol	×	Ya_sf (36) 

### Summary of Chemical Flows Table S 4 summarizes all the chemical flows in the system that are proportional to the chemical mass in the “from” compartment (source terms are handled below)
.

Table S 4 . Summary of chemical flows in the fugacity module of SHEDS
- HT **To From**  **Mechanism Chemical Flow Rate**  **(per unit chemical mass in 'from' compartment)**  surfaces air small particles
- deposition A f ×	L a,s × iZV a × CP s × PD a ,s 

### surfaces air large particles
- deposition A f ×	L a,l × iZV a × CP l × PD a,l 

### surfaces air diffusion A f ×	iZV a × ugmol × Ya

_ s f 

### outdoors air bulk flow AER O 

### loss air small particles
- cleaning MP a,s ×	iZV a × CP s × CL a,s 

### loss air large particles
- cleaning MP a,l ×	iZV a × CP l × CL a,l 

### loss air degradation D a 

### Air surfaces small particles
resuspension MP sf,s ×	iZV sf ×	CP s ×	R sf ,s 

### Air surfaces large particles
resuspension MP sf,l ×	iZV sf ×	CP l ×	R sf ,l 

### Air surfaces diffusion iZV sf × A f × ugmol × Ya

_ s f 

### loss surfaces small particles
- cleaning MP sf,s ×	iZV sf x	CP s ×	CL sf ,s 

### loss surfaces large particles
- cleaning MP sf,l ×	iZV sf x	CP l ×	CL sf ,l 

### loss surfaces degradation D sf 

### Construction of Jacobian Matrix Define the following composite expressions to simplify the construction of the equations in the Jacobian matrix for solution of the system: CL a =	iZV a ×	(MP a ,s ×CP s ×CL a,s +	MP a,l ×CP l ×CL a, l ) (37) CL sf =	iZV sf ×	(MP sf ,s ×CP s ×CL sf

,s +	MP sf,l ×CP l ×CL sf , l ) (38) Dep =	iZV a ×	A f ×	(L a,s ×CP s ×DP a,s +	L a,l ×CP l ×DP a, l ) (39) Res =	iZV sf ×	A f ×	(MP sf ,s ×CP s ×R sf

,s +	MP sf

,l ×CP l ×R sf

, l ) (40) Diff sf = iZV sf × ugmol ×A f × Ya

_ s f (41)Diff a = iZV a × ugmol ×A f × Ya

_ s f (42) 

### The Jacobian elements are then given by: J 1,1 =	AER o + D a + CL a + Dep + Diff a (43) J 1,2 = − ( Res + Diff sf ) (44) J 2 , 1 = − ( Dep + Diff a ) (45) J 2 , 2 =D sf + CL sf + Res + Diff sf (46) 

### In addition, there may be chemical source terms in each compartment. These are chemical inflows that are constant in time and do not depend on the amount of chemical in any compartment. There are only three such terms
- two corresponding to the air compartment and one to surfaces
. The air compartment may have inflow from outdoor air, or an in
-home source, or both. The floor compartment may have a single source term. All source terms have units of [ μg /d]: S 1 =	C out ×	AER o ×	V a +	CS a ×	V a (47) S 2 = CS a ×A f (48) 

### Solution of the Model The equation for the system of masses in each compartment is

d ( ) dt = − J M (t) + S (49) 

### Separating the chemical mass vector M( t) into a time
- dependent part **MT** (t) and a constant part **MC** : M (t)	= MT (t) + MC (50) 

### Then ( ) 

### = − J ( t) (51) and J MC = S (52) 

### The mass vectors **M** (t), **MT** (t), and **MC** , along with the source vector **S** , are 2x1 vectors with the first component representing the air compartment and the second representing the floor compartment. The Jacobian matrix J is 2x2. These e quations are simple enough that the so lutions may be given explicitly. Let the initial masses in the air and floor compartments be m0 , a 

### and m0 ,s f 

### , respectively, in units of micrograms. In summary, l et


### r = (J ) + 4 (J J )
− 2 (J J ) + (J ) (53 )

### mc = (J × S
− J × S ) / (J × J
− J × J ) (54)


### mc = (
− J × S + J × S ) / (J × J
− J × J ) (55) 

### mt , 

### = m , 

### – mc (56) 

### mt 0 , f 

### = m 0 , f 

### – mc f 

### ( 57 ) The eigenvalues and eigenvectors of the Jacobian matrix are λ = (J + J + r ) 2

⁄ ( 58 ) λ = (J + J
− r ) 2

⁄ ( 59 )

= = + J
− J

2 J ( 60 )

= = − J + J

− 2 J ( 61 ) The determinant of the eigenvalue matrix is = − = − 4 J
. In general, the initial state is a mix of the two eigenstates with amounts given by the constants

, , , and . Each eigenstate decays exponentially at a rate that depends on its eigenvalue: ( ) = k e + k e ( 62 ) ( ) = k e + k e ( 63 ) After some algebra, these constants are found to be k = mt , 

### − mt , 

### ( 64 ) k = − mt , 

### + mt , 

### ( 65 ) k = mt , 

### − mt , 

### ( 66 ) k = − mt , 

### + mt , 

### ( 67 ) These equations determine the time
- dependent mass **MT** (t). The total chemical mass in each compartment is then **MT** (t)+**MC** : ma ( t) = mc + k e + k e ( 68 ) mf( t) = mc + k e + k e ( 69 ) For each person in the simulation, for each indirect scenario, the time t is determined by sampling a uniform distribution from t=0 to t=356/FR (70)

### where FR is the frequency of use of the product containing the chemical. Corresponding air and surface concentrations for the selected time point are then calculated, and exposures via the indirect pathway are calculated as described in Section c below. **b. Direct**  **Pathway Exposure Methods** For each simulated individual, exposure via the direct pathway (dermal route) is calculated as E , = U × prob × M × F × F × F × 1 E 6 

### ( 71 ) E D,derm 

### is the effective dermal exposure in μ g on the simulated day. F com p 

### is the mass fraction of chemical in the applied product, F cont 

### is the fraction of the mass of the product used that comes in contact with the skin, and F ret 

### is the fraction of product retained on the skin after the direct use event (i.e. not washed off). F cont 

### and F ret 

### are product category dependent. U is either zero or one, based on a Bernoulli (binomial ) sample using the usage prevalence (PR) , which is the fraction of the population using the product
. FR is the usage frequency, expressed as the average number of uses per year, for users. M is the mass of the given product applied on a usage day [g]; 1E6 converts g to μg . The prob function (which stands for probabilistic rounding) takes one or more real arguments and randomly selects one of the integers o n either side of the value , using the distance to the integers as weights. For example, if the argument is 0.7, then prob (0.7) returns a value of one 70% of the time, and a value of zero the other 30% of the time. T hus the prob function determines the number of product usage events on the modeled day. Exposure for the ingestion route of the direct pathway (E D,ing 

### , μ g) is : E , = U × prob × M × F × F × 1 E 6 

### ( 7 2 ) The only difference between this equation and the above dermal equati on is the replacement of F ret 

### by F ing 

### , the fraction of the applied product mass that is ingested
. For the inhalation of vapor scenario, SHEDS
- HT calculate s an estimate of the evaporation amount from standard chemical properties. It is assumed th at the evaporation rate is proportional to the vapor pressure, a refinement of an instantaneous release assumption. A standard is set for this by assuming that a chemical with a vapor pressure (VP) equal to total atmospheric pressure would fully evaporate in one minute (if there was enough air to avoid saturation). The air concentration in μ g /m3 

### is given by C , = M × F × × D × × 1 E 6 

### ( 7 3 ) The P a 

### term is atmospheric pressure, D is duration of use in minutes, and V evap 

### is the volume into which the evaporation occurs, which is assumed to be room volume of 5 m3 

### in SHEDS. The calculated C A 

### value is compared to the saturation air concentration which may not be exceeded, no matter how much chemical is present. The daily inhalation exposure (E D,vap 

### , μ g) is : E , = U × prob × C , × × BVA × PAI 

### ( 7 4 ) D is the duration of the direct use in minutes; dividing by 1440 gives fraction of the day. The parameter BVA is the basal alveolar ventilation rate in cubic meters of air per day, which is a function of the person’s age, gender, and body weight. The phys ical activity index (PAI) is the duration
-weighted average breathing rate expressed as a unitless multiple of the basal rate. The PAI for each person for each micro is supplied by the activity diary summary file, and was determined from the metabolic equivalent

### (METS) values associated with each CHAD activity
. PAI and BVA are determined for each person from the CHAD diary using methods that have been previously described (Glen et al., 2012). The other direct inhalation scenario is the inhalation of aerosol s or sprays. This is generally similar to vapor inhalation, except that the airborne concentration depends on the formation and release of droplets, rather than on vapor pressure. Air concentration ( μ g /m3 

### ) in this case is given by: C , = × × × 1 E 6 

### ( 7 5 ) The default values for cloud volume V cloud 

### and airborne fraction F airb 

### are equivalent to those used in ConsExpo expos ure model (Delmaar et al. 2005) . The corresponding inhalation exposure E D ,aer 

### is then given by an equation analogous to eq. 7 4.

**c. Indirect Pathway Methods:**  **Indirect Exposure Equations** Exposure to an indirect source results when a person encounters the specified chemical in the residence after its direct use, or “post
- application”. SH EDS
- HT uses a set of generic microenvironments (hereafter called “micros”) to determine the simulated person’s surroundings and the amount of chemical present. The model uses summaries of CHAD activity diaries to determine the amount of time spent in each micro by the simulated person. Exposure occurs as individuals contact different media within the microenvironment. These media can be user
- defined but are typically air, surfaces (including floors), and pets. In this case study, only surfaces and air media are used; any products used on pets are assumed to be applied to surfaces as no distinction was made in these runs between transfer rates or contact probabilities for pets versus surfaces. Exposure is proportional to both the contact time and the concentration (calculated from the fugacity module) , and also depends on behavioral factors such as a transfer coefficient or chemical factors (such as the availability for potential transfer). The indirect pathway exposures in SHEDS
- HT are daily totals over all the micros, and are expressed as four specific routes: dermal, inhalation, hand
-to - mouth (non
- dietary) ingestion, and object
-to - mouth (non
- dietary) ingestion. Inhalation exposure via the indirect pathway is given by E , = , × × BVA × PAI 

### ( 7 6) where C A,I 

### is the average daily air concentration in the residence due to indirect sources ( μ g /m3 

### ), D is the duration of time spent in the residence (min) and BVA x PAI is the daily volume of inhaled air (m3 

### ) as described above. The indirect dermal route refers to chemical getting on the skin by touching contaminated surfaces. The dermal exposure in SHEDS
- HT is the amount of chemical transferred onto the skin (per day), regardless of what happens to that chemical later. The dermal dose is the amount of chemical that enters the body by being absorbed through the skin. Typically, only a few percent of the dermal exposure becomes dermal dose. The remainder can be washed off, ingested (by hand
-to - mouth contact), or removed without washing by dermal brush
- off. The dermal dose and hand
-to - mouth exposure both depend on the dermal exposure and on the size of the competing removal terms. Dermal exposure via the indirect route (μg/day) due to contact with surface media is given by: E , = C × D × F × 

### ( 7 7)

### The available fraction F avail 

### gives the fraction of the chemical present on surfaces that can be removed by touching. The transfer coefficient TC derm 

### quantifies the rate of transfer of chemical (cm 2

### /hr). The parameter D c 

### is the contact duration with surfaces (min/day), and 60 is a min/hr conversion factor. Contact durations are calculated as the product of the contact probability for the media and the time spent in the microenvironment by that person. Exposure via the object
-to - mouth route is gi ven by E = E × F 

### ( 7 8) This equation allows the object
-to - mouth exposure pathway to be parameterized in terms of the indirect dermal exposure plus o ne route - specific fraction (F OM

### ) . An appropriate distribution of F OM 

### was determined from SHEDS
- Multimedia, which uses a more complex equation on a more finely resolved time
- step to model the object
-to - mouth pathway. The hand
-to - mouth and object
-to - mouth exposures are combined to give non
- dietary (indirect) ingestion expo sure: E , = E + E 

### ( 7 9) Hand
-to - mouth exposure EHM 

### is considered a chemical removal process in SHEDS
- HT and is described below. **d. Dietary Exposure Methods**  Dietary exposures in SHEDS
- HT are calculated by determining the total mass of a chemical present in the food eaten by a simulated person within a day. SHEDS
- Multimedia considers on the order of 450 different food commodities that may contain chemical, and requires a distribution of chemical residues for each. SHEDS
- HT has simplified this approach by considering larger food groups, specifically a set of 41 crop groups and drinking water. The list of crop groups is given in Table S 3 . These default groups allows the user to input fewer chemical residue distributions while still maintaining variab ility in residues across food types due to differences in agricultural treatments or packaging. Default food intake information in SHEDS
- HT is also provided on a crop
- group level. The SHEDS
- HT intake diaries were developed from the National Health and Nutrition Examination Survey
- What We Eat in America (NHANES
- WWEIA) two
- day food diaries. Each NHANES food diary was processed to calculate the mass of each crop group consumed. The diaries are stored in SHEDS
- HT by age and gender, and are sampled for eac h simulated individual in a manner analogous to the CHAD activity diaries. When distributions of chemical residues in each crop group (CG) are also supplied as input, daily dietary exposures can be calculated as E = M × C + ∑ M × C (8 0) where drinking water and crop group residue concentrations (C w 

### and C cg 

### , μ g/g) are sampled once per person and the consumed mass of water and crop group (M w 

### and M cg 

### , g) are obtained from the sampled food diary for the individual.

### e. **Total Chemical**  **Exposures by Route** The SHEDS
- HT model is linear; total exposure for each route (inhalation, dermal, and ingestion) are summed over the available pathways. Total inhalation exposure for a given scenario is the sum of the exposures due to direct inhalation of aerosol, direct inhalation of vapor, and inhalation of chemical from indirect sources: E = E , + E , + E , 

### (8 1) Total ingestion exposure is the sum of exposures due to incidental ingestion during direct use, dietary ingestion, and ingestion of chemical with indirect sources (via hand
-to - mouth and object
-to - mouth pathways): E = E , + E + E , 

### (8 2) Total dermal exposure is given by the sum of the dermal exposures due to direct and indirect sources: E = E , + E , 

### (8 3) This dermal exposure can be thought of the as the total mass of new chemical that ends up on the skin over the simulated day. This chemical can subsequently be removed by the processes described below. Finally, the total route
- specific exposures across all scenarios are summed to get total chemical exposure for each pathway: E , = ∑ E 

### (8 4) E , = ∑ E 

### (8 5) E , = ∑ E 

### (8 6) Here J is the number of scenarios present for the chemical. In the case of consumer products, multiple scenarios will exist for each type of product containing the chemical. **f. Dermal Removal Processes**  There are five competing processes for removing chemical from the surface of the skin: 1) dermal absorption , 2) hand
-to - mouth transfer , 3) bathing , 4) hand washing, and 5) brush
- off. One of the distinctive features of all the SHEDS models is that more frequent hand washing and/or bathing will lower both the dermal dose and the hand
-to - mouth exposure. Even though SHEDS
- HT is a simpler model than the other SHEDS models, it was considered necessary to maintain these features. Chemical removal by each of the se five processes is modeled as a fraction of the dermal exposure from all direct and indirect scenarios: R = E , × F 

### (8 7) Where F = F HM (

### hand
-to - mouth transfer), F A,derm 

### (dermal absorption), F HW 

### (hand washing) , F BA 

### (bathing), or F BO 

### (brush off). As noted earlier, the SHEDS
- HT exposure module models one day per person, in a single time step. SHEDS
- Multimedia included the potential of carryover of dermal loading of chemical from one event to the next, and from one day to the next. As part of the SHEDS
- HT

### simplification, it is implicitly assumed that the modeled day in SHEDS
- HT ends with the same carryover as it began. The total chemical removed from the skin equals the new exposure on the modeled day, thus, F + F , + F + F + F = 1 

### (8 8) The means of the five F distributions sum to one. However, because the F values are randomly sampled, the five random samples will (almost) never sum to exactly one. Hence, the sampled values are interpreted as relative contributions to the removal. Each sample value is divided by the sum of the five, to force the standardized fractions to sum to unity. Each of the five removal processes is as signed an amount equal to its standardized fraction of the dermal exposure. For the hand
-to - mouth pathway, the exposure is the amount of chemical entering the gastrointestinal (GI) tract after removal from the hands. Thus, E = E , × F 

### (8 9) F HM 

### is a function of the hand
-to - mouth frequency (Freq HM 

### ) and the fraction of the hand area entering the mouth (AHM 

### ), both of which are SHEDS
- HT inputs. The relationship between these input parameters and daily
- level estimates of F HM 

### were estimated from runs of SHEDS
- MM (which operates on a more detailed event - level time scale). The fitted relationship is: F = R × e / × A × Freq 

### ( 9 0) where R

HW 

### is the fraction of chemical removed in a single handwash (an input) and NHW 

### is the sampled number of handwashes per day for the simulated person (based on the input parameter FreqHW 

### , the frequency of handwashing). The daily removal fraction due to handwashing (F HW 

### ) was fit in a similar manner using SHEDS
- MM results. The resulting relationship is F = R × 1
− e /
. 

### ( 9 1) The dermal dose is the amount of chemical absorbed into or through the skin. Thus, D = E , × F , 

### ( 9 2 ) F BA 

### and F BO 

### are inputs to the model; F BO 

### is > 0 on every simulated person
- day, and F BA 

### is > 0 if a bath occurs on the simulated person
- day. A bath/shower (on days when it occurs) will remove 70% of that day’s dermal exposure, on average. In reality, the amount removed would depend on whether the exposure occurs primarily before or after the bath or shower. However, SHEDS
- HT considers a whole day to be a single modeling time step, and there is no explicit sequence to the contact and removal processes. SHEDS
- HT implicitly accounts for such effects in the variability distribution for the removal terms. Since a bath removes 70% on average, the other four removal processes total only 30% on bath days (on average), but they total 100% on non
-bath days. Therefore, on average the absorbed dermal dose and the hand
-to - mouth transfer are substantially hi gher on non
-bath days. Similarly, the fraction removed by hand washing has a higher mean on days when the number of hand washings is higher. Again, the dermal dose and the hand
-to - mouth transfer are substantially higher on days with little or no hand washing.

### g. **Absorption Rates: Intake**  **Dose Estimates** SHEDS
- HT uses simple fractions to track the fate of chemical once it has entered the body. Dermal absorption is one of the competing removal processes discussed above (eq. 9 2). For inhalation, the amount absorb ed is given by: D = E , × F , 

### (9 3) Similarly, for ingestion the absorbed dose is given by: D = E , × F , 

### ( 9 4) The total absorbed (intake) dose is the sum over the inhalation, ingestion, and dermal pathways: D = D + D + D 

### ( 9 5) All of the variables above have units [μg/day]. The current approach of assigning a distribution of absorption rates will be retained while chemical
-property -related (QSAR
-based) approaches are investigated for these pathway s. 

### F. **References** 1. Goldsmith, M.R., et al., Development of a consumer product ingredient database for chemical exposure screening and prioritization. Food Chem Toxicol, 2014. **65** : p. 269
- 79. 2. NLM. The Household Products Database

-National Library of Medicine . 2013 ; Available from: http://householdproducts.nlm.nih.gov/
. 3. USDA. Pesticide Data Program . 2013; Available from: http://www.ams.usda.gov/AMSv1.0/pdp
. 4. Glen G , Zartarian V , Smith L , and Xue J. The Stochastic Human Exposure and Dose Simulation Model for Multimedia, Multipathway , Chemicals (SHEDS
- Multimedia): Residential Module. SHEDS
- Residential version 4. Technical Manual. Office of Research and Development, US EPA. 2012. Available at: http://www.epa.gov/heasd/research/sheds/user_information.html
. 5. Delmaar, J., M. Park, and J. van Engelen, ConsExpo 4.0 Consumer Exposure and Uptake Mod els Program Manual. RIVM report 320104004/2005 . 2005, National Institute for Public Health and the Environment. 

### G. **Attachments** SHEDS
- HT Code, Input Files, and Case Study Results for a population of 1000 individuals.