Alcohols, C9-11, branched and linear, ethoxylated, sulfates, sodium salts

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 Category Approach Justification document provided in IUCLID6 Section 13.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Materials and methods

Test material

Test material information

Constituent 1

Reference substance name:

Alcohols, C9-11, branched and linear, ethoxylated, sulfates, sodium salts

EC Number:

500-465-4

EC Name:

Alcohols, C9-11, branched and linear, ethoxylated, sulfates, sodium salts

Cas Number:

160901-28-0

Molecular formula:

CnH2n+1(OCH2CH2)mOSO3Na; n = 9 - 11, m = 1 - 2.5

IUPAC Name:

Alcohols, C9-11, branched and linear, ethoxylated, sulfates, sodium salts

Radiolabelling:

yes

Test animals

Species:

rat

Strain:

Wistar

Sex:

not specified

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Individual metabolism cages: yes
- Diet (ad libitum): Altromin standard diet
- Water (ad libitum): tap water

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21-22°C

Administration / exposure

Type of coverage:

semiocclusive

Vehicle:

other: aqueous solution

Duration of exposure:

15 min (Sacrifice after 48h) & 48 h

Doses:

1%

No. of animals per group:

3

Control animals:

no

Details on study design:

TEST SITE
- Preparation of test site: shaving
- Area of exposure: 10 cm2
- Type of cover used: glass capsule

SITE PROTECTION / USE OF RESTRAINERS FOR PREVENTING INGESTION: yes

REMOVAL OF TEST SUBSTANCE
- Washing procedures and type of cleansing agent: with and without washing with lukewarm water
- Time after start of exposure: 15 min & 48 h

SAMPLE COLLECTION
- Collection of blood: no
- Collection of urine and faeces: yes
- Collection of expired air: no (not possible, because 35S-marked)

ANALYSIS
- Method type for identification: TLC

Results and discussion

Signs and symptoms of toxicity:

not examined

Dermal irritation:

not examined

Absorption in different matrices:

The mean amount of sodium laureth sulfate removed from the skin surface (skin wash) ranged from 92.8% to 97.2% of the dose applied when the skin was washed after 15 min exposure and from 91.6% to 98.4% when the skin was not washed until sacrifice. This demonstrates that the test substance has mostly remained on the skin surface.
The amounts in faeces and skin could not always be quantified, since it was below the analytical lower limit of quantification (LLOQ).
The mean absorbed dose in the first experiment, sum of the amounts found in urine, faeces and skin, was about 0.1%; without washing 0.9% in mean was absorbed.
The mean recovery values varied from 98.6% to 103% and 92.6% to 101%, respectively.

Total recovery:

98.6% - 103% (with washing)
92.6% - 101% (without washing)

Percutaneous absorption

Percutaneous absorption 1

Dose:

1%

Parameter:

percentage

Absorption:

< 1 %

Remarks on result:

other: 15 min

Remarks:

The mean absorbed dose of sodium laureth sulfate was 0.1%.

Percutaneous absorption 2

Dose:

1%

Remarks on result:

other: 48h

Remarks:

The mean absorbed dose of sodium laureth sulfate was 0.9%.

Applicant's summary and conclusion

Conclusions:

Under the use conditions (rinse off after 15 minutes) only 0.1% of the applied surfactant was absorbed. In another assay the test substance was not rinsed off for 48 h. Here 0.9% of the applied test substance was absorbed through the rat skin. Thus, under these stringent conditions, absorption is considered to be very low.