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Toxicological information

Dermal absorption

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Administrative data

Endpoint:
dermal absorption, other
Remarks:
QSAR
Type of information:
(Q)SAR
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Data source

Referenceopen allclose all

Title:
IH SkinPerm (v2.04)
Author:
AIHA
Year:
2018
Bibliographic source:
https://www.aiha.org/get-involved/VolunteerGroups/Pages/Exposure-Assessment-Strategies-Committee.aspx
Reference Type:
publication
Title:
Dermal absorption of chemicals: estimation by IH SkinPerm
Author:
Tibaldi R, ten Berge W, Drolet D
Year:
2014
Bibliographic source:
J Occup Environ Hyg.,11(1):19-31

Materials and methods

Test guideline
Guideline:
other: REACH Guidance on QSARs R.6
Principles of method if other than guideline:
IH SkinPerm (v2.04) is a mathematical tool for estimating dermal absorption. The rate of mass build-up (or loss) on the skin comes from the deposition rate onto the skin minus the absorption rate into the Stratum Corneum (SC) and the amount evaporating from the skin to the air.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
SMILES (used for QSAR prediction): C(C)(C)(CC)OOC(C)(CC)OOC(C)(C)CC
Molecular Formula: C14 H30 O4
Molecular weight (g/mole): 262.39

Test animals

Species:
other: human

Administration / exposure

Type of coverage:
open
Vehicle:
unchanged (no vehicle)
Details on study design:
DATA INPUT
Molecular weight: 262.39 g/mol
Temperature: 25 °C
Vapour Pressure: 1.57 Pa (Epiwin)
Water solubility: 19 mg/L
Log Kow: 6.39 (Epiwin)
Density: 1000 mg/cm3 (default value, the organic peroxide cannot be handled safely in pure form)
Melting point: 55.31°C (Epiwin)

SCENARIO PARAMETERS
- Instantaneous deposition
Deposition dose*: 1000 mg
Affected skin area**: 1000 cm²
Maximum skin adherence***: 0.5 mg/cm²
Thickness of stagnant air****: 1 cm
Weight fraction: 1
Timing parameters
. Start deposition: 0 hr
. End time observation: 8 hr
Report parameters
. Calculation (intervals/hr): 10000
. Report (intervals/hr): 100

- Deposition over time
Affected skin area**: 1000 cm²
Maximum skin adherence***: 1 mg/cm²
Dermal deposition rate: 0.5 mg/cm²/hr
Thickness of stagnant air****: 1 cm
Weight fraction: 1
Timing parameters
. Start deposition: 0 hr
. Duration of deposition: 8hr
. End time observation*: 8 hr
Report parameters
. Calculation (intervals/hr): 10000
. Report (intervals/hr): 100

*Default value defined according to the internal validation study
**Estimated skin surface of two hands of an adult.
***The skin adherence field is greyed out and a default of -1 is indicated if the substance is a liquid at 25°C. Smart logic is built into IH SkinPerm; the program recognizes whether a substance is a solid or liquid at standard temperature (25°C) based on the physicochemical properties. For substances
that are solids at 25°C a maximum adherence value up to 2 mg/cm² is allowed based on studies of soil-on-skin adherence. If the deposition rate results in an increase above the input figure (0.2-2 mg/cm²), it is assumed that the surplus disappears just by removal from the skin.
*** 3 cm if clothing involved, 1 cm if bare skin involved

Results and discussion

Percutaneous absorptionopen allclose all
Time point:
8 h
Dose:
1000 mg
Parameter:
percentage
Absorption:
30.9 %
Remarks on result:
other: Instantaneous deposition
Time point:
8 h
Dose:
1 mg/cm²/h
Parameter:
percentage
Absorption:
12.46 %
Remarks on result:
other: Deposition over time for 8 hr

Applicant's summary and conclusion

Conclusions:
The dermal absorption of (1-methylpropylidene)bis[tert-butyl] peroxide is estimated to be<= 50%.
Executive summary:

The dermal absorption of (1-methylpropylidene)bis[tert-butyl] peroxide leads to the following results, obtained using the SkinPerm v2.04 model according to the input data:

 

Instantaneous deposition

 

Deposition over time

End time observation 8 hr

Total deposition (mg) or deposition rate (mg/cm²/hr)

1000

1

Fraction absorbed (%)

30.9

12.46

Amount absorbed (mg)

 309

597

Lag time stratum corneum (min)

 4.1

4.1

Max. derm. abs. (mg/cm²/h)

0.0374 

0.0374


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