Zinc dodecyl hydrogen disulphate

Dermal absorption

Administrative data

Endpoint:

dermal absorption in vivo

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Refer to the Analogue Approach Justification document provided in IUCLID Section 13.

Cross-reference

Reason / purpose for cross-reference:

read-across source

Reference

Endpoint:

dermal absorption in vivo

Type of information:

experimental study

Adequacy of study:

other information

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Expert judgement combined with experimental data.

Justification for type of information:

Refer to the Analogue Approach Justification document provided in IUCLID Section 13.

Principles of method if other than guideline:

No guideline exists for this type of appraisal.

GLP compliance:

no

Radiolabelling:

other: partly

Species:

other: human, rat, guinea-pig

Details on test animals or test system and environmental conditions:

not applicable

Type of coverage:

other: Various, for details see HERA report and SIDS

Vehicle:

not specified

Duration of exposure:

Various, for details see HERA report and SIDS

Doses:

Various, for details see HERA report and SIDS

No. of animals per group:

Various, for details see HERA report and SIDS

Absorption in different matrices:

Absorption by the percutaneous route is limited, since anionic surfactants tend to bind to the skin surface (Howes, 1975; Black and Howes, 1980). Early studies with isolated human skin were unable to detect penetration of a homologous series of AS, ranging from C8 to C18 (Blank and Gould, 1961). Animal studies confirmed a low level of percutaneous absorption of AS. Less than 0.4% of a 3 μmol dose of 35S-labeled C12AS-Na was percutaneously absorbed in guinea pigs, based on recovery of the radiolabel in urine, faeces and expired air (Prottey and Ferguson, 1975). Studies with rats indicated that pre-washing of the skin with surfactant enhanced AS skin penetration (Black and Howes, 1980).

For consumer exposure, actual dermal absorption is below 1% (Rice, 1977) or very low (Schäfer and Redelmeier, 1996), therefore a default assumption of 1% dermal absorption was taken for deriving the DNEL. Since the dermal absorption decreases with increasing concentration of a solution this percentage can be expanded to workers as a worst case approach.

Conversion factor human vs. animal skin:

not applicable

Materials and methods

Principles of method if other than guideline:

No guideline exists for this type of appraisal.

Test material

Test material information

Constituent 1

Reference substance name:

Sulfuric acid, mono-C12-14 (even numbered)-alkyl esters, zinc salts

Molecular formula:

Not applicable. UVCB substance

IUPAC Name:

Sulfuric acid, mono-C12-14 (even numbered)-alkyl esters, zinc salts

Results and discussion

Absorption in different matrices:

Absorption by the percutaneous route is limited, since anionic surfactants tend to bind to the skin surface (Howes, 1975; Black and Howes, 1980). Early studies with isolated human skin were unable to detect penetration of a homologous series of AS, ranging from C8 to C18 (Blank and Gould, 1961). Animal studies confirmed a low level of percutaneous absorption of AS. Less than 0.4% of a 3 μmol dose of 35S-labeled C12AS-Na was percutaneously absorbed in guinea pigs, based on recovery of the radiolabel in urine, faeces and expired air (Prottey and Ferguson, 1975). Studies with rats indicated that pre-washing of the skin with surfactant enhanced AS skin penetration (Black and Howes, 1980).

For consumer exposure, actual dermal absorption is below 1% (Rice, 1977) or very low (Schäfer and Redelmeier, 1996), therefore a default assumption of 1% dermal absorption was taken for deriving the DNEL. Since the dermal absorption decreases with increasing concentration of a solution this percentage can be expanded to workers as a worst case approach.

Conversion factor human vs. animal skin:

not applicable