Poly(oxy-1,2-ethanediyl), .alpha.-sulfo-.omega.-hydroxy-, C8-10-alkyl ethers, sodium salts

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Version / remarks:

adopted in 2010

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit

Test material

Test material information

Constituent 1

Reference substance name:

Alcohols, C8-10, ethoxylated, sulfates, sodium salts

EC Number:

939-523-2

Cas Number:

1471312-55-6

Molecular formula:

not available

IUPAC Name:

Alcohols, C8-10, ethoxylated, sulfates, sodium salts

Test material form:

semi-solid (amorphous): gel

Remarks:

paste

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: EpiDerm™

Source strain:

other: not applicable (human skin model)

Details on animal used as source of test system:

not applicable (human skin model)

Justification for test system used:

The used test system is in line with OECD TG 439.

Vehicle:

unchanged (no vehicle)

Details on test system:

An in-vitro study with the EpiDermTM human skin model comprising a reconstructed epidermis with a functional stratum corneum was performed. The EpiDermTM tissues were obtained by MatTek. The tissue was moistened with 25 µL DPBS (Dulbecco`s Phosphate Buffered Saline) to ensure good skin contact before 25 mg of the test substance were applied directly atop the EpiDermTM tissue. DPBS was used as negative control while 5% SDS (Sodium dodecyl sulfate) was used as positive control. A total of 3 tissues per dose group were used in duplicate. Irritation properties of the test substance are identified by the decrease of cell viability after exposure as determined by using the MTT reduction assay. The tissues were maintained at 37 °C in humidified atmosphere (5% CO2/95% air). All media used during the study (for instance the incubation medium and MTT medium) were pre-warmed. After treatment, tissues were incubated at 37 °C in humidified atmosphere for 35 min and placed at room temperature thereafter. After 60 min the tissues were washed with DPBS, placed in pre-warmed incubation medium and were further incubated for 24 h at 37 °C in humidified atmosphere. After a medium change the tissues were incubated for additional 18 h prior to incubation in MTT medium for 3 h. After incubation in MTT the tissues were three times rinsed with DPBS before extraction of the reduced MTT with isopropanol for 2 hours. Per each tissue two aliquots of the extract were transferred into 96-well plates and analysed in a plate spectrophotometer. The MTT reducing potential and the coloring potential of the test substance as possible confounding factors were assessed.
Assessment criteria:
A test substance is concluded to be irritating if the relative mean tissue viability after 60 minute exposure and 42 hours post-treatment incubation is below 50%.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Remarks:

mean value of all tissues

Run / experiment:

60 min exposure

Value:

6.8

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

positive indication of irritation

Remarks:

Reversibility: not applicable.

Other effects / acceptance of results:

The test item showed irritating potential (for details, see Table 1). However, only two experiments with test item treated tissues instead of three were evaluated due to loss of one tissue during washing. As each experiment was performed in duplicate 4 tissues were assessed. The test meets the acceptance criteria (See: Any other information on materials and methods incl. tables.)

Any other information on results incl. tables

Table 1: Summary of results

Test group	n	Treatment period (min)	Mean OD550value	Viability (%)	Mean inter tissue viability difference (%)
Negative control	3	60	1.78	100	15.8
Test item	2*	60	0.12	6.8	0.8
Positive control	3	60	0.12	6.6	0.9

* Only two test item treated tissues instead of three were evaluated due to loss of one tissue during washing.

Applicant's summary and conclusion

Interpretation of results:

other: Skin irrit. 2 (H315) according to Regulation (EC) No 1272/2008

Conclusions:

There is regulatory acceptance in the EU that a substance can be considered non-irritant and non-corrosive based on a negative result in the Reconstructed human epidermis test method (in vitro skin irritation). A positive in vitro irritation response is not conclusive with respect to classification of the test substance as irritant (Skin Irritant Cat. 2) or corrosive or Skin Corrosive Cat. 1) and therefore requires further evaluation and/or data generation. Previously, an in vitro skin corrosion test was conducted (Study-ID: 122043) with the result "non-corrosive". The outcome of the present skin irritation test is positive. Thus, taken together the results from both tests, it can be concluded that the substance meets the criteria as a Skin Irritant Cat. 2 (H315).