Appendix of the Screening Assessment for the Challenge

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Octamethylcyclotetrasiloxane
(D4)

Chemical Abstracts Service Registry Number
556-67-2

Environment Canada
Health Canada

November 2008

Back to the Screening Assessment

Appendix

• Appendix 1: Upper-bounding Estimates of Daily Intake of D4 by the General Population in Canada (µg/kg-bw per Day by Various Age Groups)
• Appendix 2: Consumer Exposure Modelling
• Appendix 3: Summary of Health Effects Information for Octamethylcyclotetrasiloxane
• Appendix 4: Review of D5 Probabilistic Exposure Assessment
  • Figure 1. Contribution of scenarios to children's mean and 90th percentile dermal exposures
  • Figure 2. Contribution of scenarios to children's mean and 90th percentile inhalation exposures
  • Figure 3. Contribution of scenarios to children's (breastfed vs. non-breastfed) mean and 90th percentile ingestion exposures
  • Figure 4. Contribution of scenarios to children's (2-4 and 4-11 years) mean and 90th percentile ingestion exposures
  • Figure 5. Contribution of exposure route to children's mean and 90th percentile total exposure (general population)
  • Figure 6. Contribution of exposure route to children's mean and 90th percentile total exposure (subsistence population)
  • Figure 7. Contribution of scenarios to adults' mean and 90th percentile dermal exposures
  • Figure 8. Contribution of scenarios to adults' mean and 90th percentile inhalation exposures
  • Figure 9. Contribution of scenarios to adults' mean and 90th percentile ingestion exposures
  • Figure 10. Contribution of exposure route to adults' mean and 90th percentile total exposure (general population)
  • Figure 11. Contribution of exposure route to adults' mean and 90th percentile total exposure (subsistence population)
• Appendix 5: Multimedia modelling input parameters for D4 in the ecological screening assessment

Appendix 1: Upper-bounding Estimates of Daily Intake of D4 by the General Population in Canada (µg/kg-bw per Day by Various Age Groups)

^[1] Assumed to weigh 7.5 kg, to breathe 2.1 m³ of air per day, to drink 0.8 L of water per day (formula fed) or 0.3 L/day (fed solid food) and to ingest 30 mg of soil per day (Health Canada 1998).
^[2] The highest concentration of D4 detected in human breast milk was10 µg/L in Sweden (Kaj et al. 2005). Breast-fed children 0-6 months of age are assumed to have an intake rate of 0.75 kg of breast milk per day (Health Canada 1998).
^[3] For exclusively formula-fed infants, intake of water is only that required to reconstitute formula. No data on detectable concentrations of D4 in drinking water were located. No data on concentrations of D4 in formula or baby food were identified for Canada. Approximately 50% of infants are introduced to solid foods by 4 months of age and 90% by 6 months of age (NHW 1990,).
^[4] The dietary intake is based on consumption of 0.3 litres of water and up to 1.18 kg of food daily. This intake pattern is presented as a hypothetical extreme case and does not reflect recommended infant feeding practice.
^[5] Assumed to weigh 15.5 kg, to breathe 9.3 m³of air per day, to drink 0.7 L of water per day and to ingest 100 mg of soil per day (Health Canada 1998).
^[6] Assumed to weigh 31.0 kg, to breathe 14.5 m³ of air per day, to drink 1.1 L of water per day and to ingest 65 mg of soil per day (Health Canada 1998).
^[7] Assumed to weigh 59.4 kg, to breathe 15.8 m³ of air per day, to drink 1.2 L of water per day and to ingest 30 mg of soil per day (Health Canada 1998).
^[8] Assumed to weigh 70.9 kg, to breathe 16.2 m³ of air per day, to drink 1.5 L of water per day and to ingest 30 mg of soil per day (Health Canada 1998).
^[9] Assumed to weigh 72.0 kg, to breathe 14.3 m³ of air per day, to drink 1.6 L of water per day and to ingest 30 mg of soil per day (Health Canada 1998).
^[10] D4 has been measured in ambient air near point sources in Canada, the United States, Europe and Asia. The highest measured concentration not near a point source, 2.4 µg/m³ in Sepstrup Sande, Denmark, was used for the level of D4 in ambient air (Norden 2005). Canadians are assumed to spend 3 h per day outside (Health Canada 1998).
^[11] D4 was detected in 15% of about 130 homes in Syracuse, New York between 2002 and 2004. The maximum concentration of D4 measured was 20.56 ppb, or 249 µg/m³ (NYIEQ 2005). The data set considered includes a survey of bedrooms in homes in Sweden in which D4 was detected in 18% of samples and at a maximum concentration of 51.2 µg/m³ (Kaj et al. 2005). Canadians are assumed to spend 21 h per day inside (Health Canada 1998).
^[12] No data on levels of D4 in Canadian drinking water were identified. D4 was not detected in two samples of surface water away from point sources in Norway. The higher limit of detection of 0.09 µg/L was used (Norden 2005).
^[13] No data were identified for the concentration of D4 in foods in Canada. The concentration of D4 in flounder filets from Norwegian waters was reported to be 1.9 ng/g on a wet-weight basis (NILU 2007). The maximum concentration of DMPS (CAS RN 9006-65-9, dimethylpolysiloxane) in certain processed food is limited by regulation to 10 ppm.^[*] A value of 1% D4 in DMPS, or 0.1 ppm in certain processed foods was assumed and it was further assumed that half of processed food and one quarter of dairy products are treated with antifoaming agents containing D4. The probable daily intake of D4 from food packaging for an adult was estimated to be less than 0.2µg/kg-bw/day (as per email from Food Packaging and Incidental Additives Section, Health Products and Food Branch of Health Canada, dated Feb. 27, 2008 unreferenced). Amounts of foods consumed on a daily basis by each age group are described by Health Canada (Health Canada 1998).
^[14] No Canadian data were available for D4 levels in soil. No D4 was detected in two soil samples from the Faroe Islands taken at an abandoned and an operating landfill. The higher limit of detection of 10 µg/kg was used (Norden 2005).
^[*] Food and Drug Regulations, Division 16. C.R.C., c. 870.

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Appendix 2: Consumer Exposure Modelling

Sample ConsExpo 4.1 Report

Product

Body lotion - women - partitioning 90/10

Compound

Compound name: Octamethylcyclotetrasiloxane
CAS RN: 556-67-2
molecular weight: 297 g/mol
vapour pressure: 140 Pascal
K_OW: 6.5 10Log

General exposure data

exposure frequency: 1.5 1/day
body weight: 69 kilogram

Inhalation model: exposure to vapour - constant rate

weight fraction compound: 0.185 fraction     
exposure duration: 12 hour       
room volume: 80 m³        
ventilation rate: 1 1/hr       
applied amount: 7.2 gram       
release duration: 12 hour       

Uptake model: fraction

uptake fraction: 0.12 fraction     
inhalation rate: 22 m³/day      

Dermal model: direct dermal contact with product - instant application

weight fraction compound: 0.185 fraction     
exposed area: 1.57E3 cm²        
applied amount: 0.8 gram       

Uptake model: fraction

uptake fraction: 0.0094 fraction     

Output

Inhalation (point estimates)

inhalation mean event concentration: 1.27 mg/m³
inhalation mean concentration on day of exposure: 0.953 mg/m³
inhalation air concentration year average: 0.953 mg/m³/day
inhalation acute (internal) dose: 0.0243 mg/kg
inhalation chronic (internal) dose: 0.0365 mg/kg/day

Dermal: point estimates

dermal load: 0.0943 mg/cm²
dermal external dose: 2.14 mg/kg
dermal acute (internal) dose: 0.0202 mg/kg
dermal chronic (internal) dose: 0.0302 mg/kg/day

Integrated (point estimates)

total external dose: 2.35 mg/kg
total acute dose (internal): 0.0445 mg/kg
total chronic dose (internal): 0.0667 mg/kg/day

Table 1. D4 - Systemic Dose by Exposure to Personal Care Products - 69-kg Woman

 

Consumer exposure modelling based on ConsExpo (RIVM 2006)

Basic assumptions:

• Body weight 69 kg
• Absorption by inhalation 12% (Utell et al. 1998, SCCP 2005); dermal absorption 0.94% (SCCP 2005); absorption by ingestion 52% (Dow Corning 1998b).
• For products left on skin except lipstick, 10% of applied amount is available to be dermally absorbed, 90% evaporates
• For lipstick, 20% is available for dermal absorption and 80% is available for absorption by ingestion.

Authorities:       

• NMI: see in references NMI 2007
• RIVM: see in references RIVM 2006
• CNS: see in references CNS 2007
• Section 71: see in references Environment Canada 2007
• Maxim: see in references Maxim 1998

Table 2. D4 - Systemic Dose by Exposure to Personal Care Products - 82.3-kg Man

 

Consumer exposure modelling based on ConsExpo (RIVM 2006)

Basic assumptions:

• Body weight 82.3 kg
• Absorption by inhalation 12% (Utell et al. 1998, SCCP 2005); Dermal absorption 0.94% (SCCP 2005)
• For products left on skin 10% of applied amount is available to be dermally absorbed, 90% evaporates

Authorities:

• NMI:                 see in references NMI 2007
• RIVM:              see in references RIVM 2006
• CNS:               see in references CNS 2007
• Section 71:        see in references Canada 2007
• Maxim:            see in references Maxim 1998

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Appendix 3: Summary of Health Effects Information for Octamethylcyclotetrasiloxane

^[1] LD₅₀ = median lethal dose
LC₅₀ = median lethal concentration
LOEL = lowest-observed-effect level
LOEC = lowest-observed-effect concentration
NOEL = no-observed-effect level
^[2] This value was checked and appears to be correct. However, we note the apparent inconsistency between an oral LD₅₀ value of 759 mg/kg-bw in rabbits and the dermal NOEL of 960 mg/kg-bw/day in the 3-week dermal rabbit study.
^[3] IUCLID (2000) and SCCP (2005) state the mid-dose to be 190 mg/kg-bw/day whereas SEHSC (2007d) states the mid-dose to be 280 mg/kg-bw/day.

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Appendix 4: Review of D5 Probabilistic Exposure Assessment

Project: D5 Probabilistic Exposure Assessment
Task: Review D5 Probabilistic Exposure Assessment conducted by Silicones Environmental, Health and Safety Council (SEHSC)
For: Health Canada (Healthy Environments and Consumer Safety Branch)
By: infoscientific, Henderson, Nevada, USA
Period: August-September, 2008

Executive Summary

A review of the D5 probabilistic exposure assessment submitted by SEHSC was done and comments to assist in preparing the screening assessment report for D5 is provided in this report.

"User Only" daily exposures were estimated based on a Monte Carlo analysis using Crystal Ball. Mean exposure and 90^th percentile exposure summaries were generated for different subpopulations (children and adults).

For dermal and inhalation exposure routes, the current assessment resulted in higher exposures than the assessment done by SEHSC. The primary reason was the consideration of "user only" subpopulation in the current assessment compared to the "user" and "non-user" subpopulations considered in the SEHSC assessment. The dermal exposure route had higher exposures for both children and adults. Diaper cream, body lotion and sunscreen contributed to higher exposures in the dermal route; soothing vapour in the inhalation route and antifoam and fish in the ingestion route.

Introduction

As a part of Canada's Chemicals Management Program, Decamethylcyclopentasiloxane (D5) has been identified by Health Canada as a material to be reviewed and considered in a screening level assessment.

SEHSC submitted information on D5 to assist Health Canada in preparing the screening assessment report for D5. The information provided included toxicity information not readily available in the literature and a comprehensive exposure assessment utilizing Monte Carlo analysis. The exposure assessment included information on the levels of D5 in different environmental media and on consumer product use patterns.

Health Canada contracted with infoscientific, USA to review the D5 probabilistic exposure assessment submitted by SEHSC and to provide comments to assist in preparing the screening assessment report for D5.

Description

SEHSC's Monte Carlo-based probabilistic assessment for D5 included the following age-dependent and exposure-route-dependent scenarios:

• Children - dermal route: body lotion, conditioner (leave in), conditioner (rinse off), diaper cream, shampoo (2-in-1) soothing vapour, spray detangler, sunscreen
• Children - ingestion route: antifoam, baby bottle nipple, fish (general population), fish (subsistence population), human milk, leafy vegetables (greens), meat, milk, pacifier, root vegetables, sipper tube, soil, straws, water
• Children - ingestion route: OTC (over-the-counter) drugs
• Children - inhalation route: indoor air, outdoor air, soothing vapour
• Adults - dermal route: after shave, body lotion, conditioner (leave in), conditioner (rinse off), foundation, hair spray, mascara, moisturizer, nail care, roll-on antiperspirant, shampoo, solid antiperspirant, soothing vapour, sunscreen, under-eye cream
• Adults - ingestion route: antifoam, fish (general population), fish (subsistence population), leafy vegetables (greens), lipstick, meat, milk, root crops, soil, water
• Adults - ingestion route: OTC (over-the-counter) drugs
• Adults: inhalation route: indoor air, outdoor air, soothing vapour

Separate route-specific and total exposure estimates were made for the following subpopulations:

• Children: ages 0 to 6 months, breastfed
• Children: ages 0 to 6 months, non-breastfed
• Children: ages 0 to 6 months, males
• Children: ages 0 to 6 months, females
• Children: ages 7 to 11 months, breastfed
• Children: ages 7 to 11 months, non-breastfed
• Children: ages 1 to 2 years, breastfed
• Children: ages 1 to 2 years, non-breastfed
• Children: ages 2 to 4
• Children: ages 6 months to 4 years, males
• Children: ages 6 months to 4 years, females
• Children: ages 4 to 11 years, males
• Children: ages 4 to 11 years, females
• Adults: ages 12 to 19 years, males
• Adults: ages 12 to 19 years, females
• Adults: ages 20 to 59 years, males
• Adults: ages 20 to 59 years, females
• Adults: ages 60+ years, Males
• Adults: ages 60+ years, Females.

The following documents and data files were provided to assist with the review process:

• D5_Kids, an Excel file, compatible with Crystal Ball, that contained all the exposure calculations for children
• D5_Adults, an Excel file, compatible with Crystal Ball, that contained all the exposure calculations for adults
• UPDATED Final Submission for Health Canada - D5, a Word file that contains information related to toxicity and exposure for D5
• Attachment 1 - Exposure Assessment for D5, a Word file that is a report explaining the probabilistic exposure assessment, including inputs used and outputs generated

The following steps were taken during the process of reviewing the D5 probabilistic assessment submitted by SEHSC:

• reviewed documents provided by Health Canada
• identified product-based exposure scenarios, exposure pathways and exposure subpopulations
• used the Excel files provided by Health Canada (D5_Kids.xls and D5_Adults.xls; files created by SEHSC) as starting points
• assured the quality of Crystal Ball-based probabilistic calculations
• generated Crystal Ball-based probabilistic Monte Carlo outputs and compared them with those listed in documents submitted by SEHSC
• commented on the robustness of industry's (SEHSC) probabilistic assessment and recommended whether it should be considered further in the screening assessment for D5

It must be mentioned that the review process did not

• validate the list of scenarios that cover all D5 exposures to children and adults
• validate the input values used in the SEHSC assessment
• validate the sources of the input values

However, the review process did

• check cells designated as Crystal Ball Assumptions (check the assignment of distributional parameters for inputs)
• check cells designated as Crystal Ball Forecasts (check the assignment of results)
• check formulas for the different calculations

A few errors were detected in the calculations. All these errors, which appeared in the formula cells, were incorrect references to formula inputs (incorrect cell references were provided).

Each exposure scenario-dermal, ingestion, or inhalation-has two use-related parameters associated with it: frequency of use/occurrence (number of times per day) and percentage of population engaged in scenario. For the parameter " frequency of use/occurrence", the values used in the SEHSC assessment were also used in the current assessment, except when the value was less than 1.0; in this case, a value of 1.0 was assigned.

The SEHSC assessment relies heavily on the parameter "percentage of population engaged in scenario" to estimate exposures for the general population which includes users and non-users. The current assessment ignores this parameter completely. For example, in the case of a scenario where 20% of the population is engaged, in a probabilistic Crystal Ball run with 200 000 simulations, the SEHSC assessment will have 160 000 estimates with zero values and 40 000 estimates with values greater than zero. On the other hand, the current assessment will have 200 000 estimates with values greater than zero. As a result, both mean exposure estimates and 90^th percentile exposure estimates generated by the current assessment will be greater than those generated by the SEHSC assessment. Conclusion: "user-only" exposures make a significant difference when comparing results generated by SEHSC and by infoscientific.

Exposure summary results were generated for 1) individual scenarios by specific exposure routes, 2) multiple scenarios by specific exposure routes (total exposure by specific exposure route) and 3) multiple scenarios aggregated over multiple routes (total exposure).

Total exposure within an exposure route is estimated by summing exposures for each scenario. Then total exposure across multiple exposure routes is estimated by summing exposures for each exposure route. Let us consider single Monte Carlo simulations within two separate probabilistic assessments: (1) a "user only" assessment (similar to the current assessment) and (2) a "user/non-user" assessment (similar to the SEHSC assessment).

In case (1), for each scenario, there is a finite probability that the individual represented in the simulation engages in that scenario. Thus, for multiple scenarios, the individual is involved only in a fraction of the scenarios and not all the scenarios considered. For those scenarios in which the individual engages, exposure estimates are generated. Total exposure is the sum of individual scenario exposures. This case can be extended to represent individuals in a general population.

By contrast, in case (2), for all scenarios, the probabilities for the individual represented in the simulation engaging in each equal 1.0 (100%). And, in this case, for multiple scenarios, the individual is involved in all the scenarios. Total exposure, which is the sum of individual scenario exposures, represents all the scenarios. The probability of an individual in a general population engaging in all the scenarios is unlikely.

Based on the above explanations for the two cases, in the current assessment, the "user only" summaries generated for individual scenarios are valid results. However, the summaries generated for total exposures, either within individual exposure routes or across exposure routes, are improbable and should be interpreted with caution. For total exposures, the estimates generated by SEHSC would be more applicable than the ones generated by the current assessment.

Adding exposures across exposure routes should be done after consideration of route-specific toxicological endpoints. If the route-specific toxicological endpoints are unequal, route-specific total exposures cannot be added without applying appropriate absorption/penetration factors and/or potency factors.

Exposure results and discussion: Children

Table 1. Children's mean exposures (based on 200 000 Crystal Ball simulations)

Table 1 summarizes all the exposure results for children as mean values. When compared with similar results generated by the SEHSC assessment, all the values are higher in the current assessment. Compared to the SEHSC assessment, the current assessment results in a difference of 1.79 to 2.32 times for total dermal exposures, in a difference of 1.00 to 13.56 times for total inhalation exposures, and in a difference of 0.97 to 1.56 times for total ingestion (general population) exposures. The primary reason for the differences is that the SEHSC assessed users and non-users whereas the current assessment considered users only.

Wherever exposures are estimated for multiple age groups, the estimates for lower age groups are usually greater than the estimates for higher age groups. Within dermal exposure scenarios, diaper cream, sunscreen and body lotion are the highest contributions; within inhalation, soothing vapour is the highest contributor; and within ingestion, the highest contributor is over-the-counter drugs for lower age groups and fish (subsistence) for higher age groups.

Table 2. Mean ingestion exposures for breastfed (BF) and non-breastfed (nBF) infants

Table 2 summarizes all ingestion-related mean exposures specific to breastfed and non-breastfed infants. There are no significant differences in the results generated by the current assessment (shown above) and the SEHSC assessment. The two highest contributors to ingestion exposure for this subpopulation are antifoam and fish (subsistence).

Table 3. Children's 90^th percentile exposures (based on 200 000 Crystal Ball simulations)

Table 3 summarizes all the exposure results for children as 90^th percentile values. When compared with similar results generated by the SEHSC assessment, all the values are higher in the current assessment. Compared to the SEHSC assessment, the current assessment results in a difference of 1.33 to 1.69 times for total dermal exposures, in a difference of 1.00 to 9.83 times for total inhalation exposures, and in a difference of 0.97 to 1.36 times for total ingestion (general population) exposures. The primary reason for the differences is that the SEHSC assessed users and non-users whereas the current assessment considered users only.

Table 4. 90^th percentile ingestion exposures for breastfed (BF) and non-breastfed (nBF) infants

Table 4 summarizes all ingestion-related 90^thpercentile exposures specific to breastfed and non-breastfed infants. There are no significant differences in the results generated by the current assessment (shown above) and the SEHSC assessment. The two highest contributors to ingestion exposure for this subpopulation are antifoam and fish (subsistence).

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Figure 1. Contribution of scenarios to children's mean and 90^th percentile dermal exposures

D5: Dermal exposures, males 0-6 months

D5: Dermal exposures, females 0-6 months

D5: Dermal exposures, males 6 months - 4 years

D5: Dermal exposures, females 6 months - 4 years

D5: Dermal exposures, males 4-11 years

D5: Dermal exposures, females 4-11 years

Figure 1 shows the contribution of scenarios to dermal exposures for children's mean and 90^th percentile exposures. As seen in the bar charts, diaper cream, sunscreen, and body lotion are the highest contributors to dermal exposures.

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Figure 2. Contribution of scenarios to children's mean and 90^th percentile inhalation exposures

D5: Inhalation exposures, males 6 months - 4 years

D5: Inhalation exposures, females 6 months - 4 years

D5: Inhalation exposures, males 4-11 years

D5: Inhalation exposures, females 4-11 years

Figure 2 shows the contribution of scenarios to inhalation exposures for children's mean and 90^th percentile exposures. As seen in the bar charts, soothing vapour is the highest contributor to inhalation exposures.

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Figure 3. Contribution of scenarios to children's (breastfed vs. non-breastfed) mean and 90^th percentile ingestion exposures

D5: Ingestion exposures, 0-6 months, breastfed

D5: Ingestion exposures, 0-6 months, non-breastfed

D5: Ingestion exposures, 7-11 months, breastfed

D5: Ingestion exposures, 7-11 months, non-breastfed

D5: Ingestion exposures, 1-2 years, breastfed

D5: Ingestion exposures, 1-2 years, non-breastfed

Figure 3 shows the contribution of scenarios to ingestion exposures for children's (breastfed and non-breastfed) mean and 90^th percentile exposures. As seen in the bar charts, the highest contributors to ingestion exposures for this subpopulation are antifoam and fish (for the general and subsistence population).

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Figure 4. Contribution of scenarios to children's (2-4 and 4-11 years) mean and 90^th percentile ingestion exposures

D5: Ingestion exposures, 2-4 years

D5: Ingestion exposures, males, 4-11 years

D5: Ingestion exposures, females, 4-11 years

Figure 4 shows the contribution of scenarios to ingestion exposures for children's (2-4 and 4-11 years) mean and 90^th percentile exposures. Exposure estimates are based on 200 000 Crystal Ball simulations. As seen in the bar charts, the highest contributors to ingestion exposures for this subpopulation are antifoam and fish (for general and subsistence population).

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Figure 5. Contribution of exposure route to children's mean and 90^th percentile total exposure (general population)

D5: Exposures, males, 0-6 months (general population)

D5: Exposures, females, 0-6 months (general population)

D5: Exposures, males, 6 mth - 4 yr (general population)

D5: Exposures, females, 6 mth - 4 yr (general population)

D5: Exposures, males, 4-11 years (general population)

D5: Exposures, females, 4-11 years (general population)

Figure 5 shows the contribution of exposure route to children's mean and 90^th percentile total exposures for the general population. The highest exposure route is dermal. In the case of children 0-6 months old, dermal exposure is followed by over-the-counter drugs and then by ingestion; however, in the case of children 6 months - 4 years old and children 4-11 years old, dermal exposure is followed by inhalation and then by ingestion.

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Figure 6. Contribution of exposure route to children's mean and 90^th percentile total exposure (subsistence population)

D5: Exposures, males, 0-6 months (subsistence population)

D5: Exposures, females, 0-6 months (subsistence population)

D5: Exposures, males, 6 mth - 4 yr (subsistence population)

D5: Exposures, females, 6 mth - 4 yr (subsistence population)

D5: Exposures, males, 4-11 years (subsistence population)

D5: Exposures, females, 4-11 years (subsistence population)

Figure 6 shows the contribution of exposure route to children's mean and 90^th percentile total exposures for the subsistence population. The highest exposure route is dermal. In the case of children 0-6 months old, dermal exposure is followed by over-the-counter drugs and then by ingestion; however, in the case of children 6 months - 4 years old and children 4-11 years old, dermal exposure is followed by inhalation and then by ingestion.

Exposure results and discussion: Adults

Table 5. Adults' mean exposures (based on 200 000 Crystal Ball simulations)

Table 5 summarizes all the exposure results for adults as mean values. When compared with similar results generated by the SEHSC assessment, almost all the values are higher in the current assessment. Compared to the SEHSC assessment, the current assessment results in a difference of about 2.16 times for total dermal exposures, in a difference of about 13.55 times for total inhalation exposures, and in a difference of about 1.24 times for total ingestion (general population) exposures. The primary reason for the differences is that the SEHSC assessed users and non-users whereas the current assessment considered users only.

Table 6. Adults' 90^th percentile exposures (based on 200 000 Crystal Ball simulations)

Table 6 summarizes all the exposure results for adults as 90^th percentile values. When compared with similar results generated by the SEHSC assessment, almost all the values are higher in the current assessment. Compared to the SEHSC assessment, the current assessment results in a difference of about 1.55 times for total dermal exposures, in a difference of about 9.44 times for total inhalation exposures, and in a difference of about 1.17 times for total ingestion (general population) exposures. The primary reason for the differences is that the SEHSC assessed users and non-users whereas the current assessment considered users only.

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Figure 7. Contribution of scenarios to adults' mean and 90^th percentile dermal exposures

D5: Dermal exposures, males 12-19 years

D5: Dermal exposures, females 12-19 years

D5: Dermal exposures, males 20-59 years

D5: Dermal exposures, females 20-59 years

D5: Dermal exposures, males 60+ years

D5: Dermal exposures, females 60+ years

Figure 7 (above) shows the contribution of scenarios to dermal exposures for adults' mean and 90^th percentile exposures. As seen in the bar charts, body lotion, sunscreen, and moisturizer are the highest contributors to dermal exposures.

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Figure 8. Contribution of scenarios to adults' mean and 90^th percentile inhalation exposures

D5: Inhalation exposures, males 12-19 years

D5: Inhalation exposures, females 12-19 years

D5: Inhalation exposures, males 20-59 years

D5: Inhalation exposures, females 20-59 years

D5: Inhalation exposures, males 60+ years

D5: Inhalation exposures, females 60+ years

Figure 8 shows the contribution of scenarios to inhalation exposures for adults' mean and 90^th percentile exposures. As seen in the bar charts, soothing vapour is the highest contributor to inhalation exposures.

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Figure 9. Contribution of scenarios to adults' mean and 90^th percentile ingestion exposures

D5: Ingestion exposures, males 12-19 years

D5: Ingestion exposures, females 12-19 years

D5: Ingestion exposures, males 20-59 years

D5: Ingestion exposures, females 20-59 years

D5: Ingestion exposures, males 60+ years

D5: Ingestion exposures, females 60+ years

Figure 9 shows the contribution of scenarios to ingestion exposures (general population) for adults' mean and 90^thpercentile exposures. As seen in the bar charts, antifoam and fish are the highest contributors to ingestion exposures.

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Figure 10. Contribution of exposure route to adults' mean and 90^th percentile total exposure (general population)

D5: Exposures, males 12-19 years (general population)

D5: Exposures, females 12-19 years (general population)

D5: Exposures, males 20-59 years (general population)

D5: Exposures, females 20-59 years (general population)

D5: Exposures, males 60+ years (general population)

D5: Exposures, females 60+ years (general population)

Figure 10 shows the contribution of exposure route to adults' mean and 90^th percentile total exposures for the general population. The highest exposure route is dermal. Dermal is followed by ingestion and inhalation.

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Figure 11. Contribution of exposure route to adults' mean and 90^th percentile total exposure (subsistence population)

D5: Exposures, males 12-19 years (subsistence population)

D5: Exposures, females 12-19 years (subsistence population)

D5: Exposures, males 20-59 years (subsistence population)

D5: Exposures, females 20-59 years (subsistence population)

D5: Exposures, males 60+ years (subsistence population)

D5: Exposures, females 60+ years (subsistence population)

Figure 11 shows the contribution of exposure route to adults' mean and 90^th percentile total exposures for the subsistence population. The highest exposure route is dermal. Dermal is followed by ingestion and inhalation.

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Appendix 5: Multimedia modelling input parameters for D4 in the ecological screening assessment