2,2'-(m-tolylimino)diethanol

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 24th - February 22nd, 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.40 (In Vitro Skin Corrosion: Transcutaneous Electrical Resistance Test (TER))

Version / remarks:

Official Journal of the European Union No. L142, 31 May 2008.

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Version / remarks:

adopted 13 April 2004

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-[(4-methylphenyl)imino]bisethanol

EC Number:

221-359-1

EC Name:

2,2'-[(4-methylphenyl)imino]bisethanol

Cas Number:

3077-12-1

Molecular formula:

C11H17NO2

IUPAC Name:

2,2'-[(4-methylphenyl)imino]diethanol

Constituent 2

Reference substance name:

2-{[2-(2-hydroxyethoxy)ethyl](4-methylphenyl)amino}ethan-1-ol

Cas Number:

878391-30-1

Molecular formula:

C13H21NO3

IUPAC Name:

2-{[2-(2-hydroxyethoxy)ethyl](4-methylphenyl)amino}ethan-1-ol

Test material form:

liquid: viscous

Details on test material:

- Appearance: clear, slightly yellowish to brown, viscous liquid
- Storage condition of test material: at room temperature in the dark

Test animals

Species:

human

Details on test animals or test system and environmental conditions:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 36.3 – 37.0
- Humidity (%): 72 – 88

Test system

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

TEST MATERIAL
- Volume applied: 50 μl

NEGATIVE CONTOL:
- Volume applied: 25 µl milliQ.

POSITIVE CONTROL
- Volume applied: 50 µl
- Concentration: 8N KOH

Details on study design:

TEST SITE
- EpiDerm Skin Model (EPI-200, Lot no.:16850 kits A and B). The model consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, highly differentiated model of the human epidermis. It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo. The EpiDerm tissues (surface 0.6 cm²) were cultured on polycarbonate membranes of 10 mm cell culture inserts. The model was obtained from MatTek Corporation, Ashland MA, U.S.A.

REMOVAL OF TEST SUBSTANCE
- Washing: phosphate buffered saline
- Time after start of exposure: 3 minutes or 1 hour

POST INCUBATION PERIOD
- 3 hours

SCORING SYSTEM:
- Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT at the end of the treatment. Cell viability was calculated for each tissue as a percentage of the mean of the negative control tissues.

BACKGROUND:
- Accelerator (PT 25E or PT 25E/2) was checked for possible direct MTT reduction in the Skin irritation test using EpiskinTM as a skin model (project 501366). Because a colour change was observed it was concluded that Accelerator (PT 25E or PT 25E/2) did interact with MTT. In addition to the normal 1-hour procedure, one freeze-killed tissue treated with test substance and one freeze-killed non treated tissue must be used for the cytotoxicity evaluation with MTT.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3-minute exposure

Value:

85

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100%

Positive controls validity:

valid

Remarks:

14%

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1-hour exposure

Value:

56

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

100%

Positive controls validity:

valid

Remarks:

8%

Any other information on results incl. tables

Accelerator (PT 25E or PT 25E/2) was checked for possible direct MTT reduction in the Skin irritation test using EpiskinTM as a skin model (project 501366). Because a colour change was observed it was concluded that Accelerator (PT 25E or PT 25E/2) did interact with MTT. In addition to the normal 1-hour procedure, one freeze-killed tissue treated with test substance and one freeze-killed non-treated tissue was used for the cytotoxicity evaluation with MTT. In the present experiment no non-specific reduction was measured.

Applicant's summary and conclusion

Interpretation of results:

other: Not corrosive in the in vitro skin corrosion test

Conclusions:

An in vitro skin corrosion test was conducted according to OECD guideline 431 and GLP principles. It is concluded that this test is valid and that the test substance is not corrosive in the in vitro skin corrosion test.

Executive summary:

In an in vitro skin corrosion test using a human skin model (EpiDerm Skin Model) according to OECD guideline 431 and GLP principles, the influence of Accelerator (PT 25E or PT 25E/2) on the viability of human skin was tested. The test substance was applied directly to 0.6 cm² cultured skin (25mg, in presence of 25 μl Milli-Q water). After 3 minutes or 1 hour, the substance was removed and cells were cultured for 3 hours in the presence of MTT. The viability of the cells was tested by reduction of MTT. Survival of unexposed skin was set at 100%, the positive control had a mean cell viability of 14% and 8% after resp. 3 minutes or 1 hour exposure whereas the test substance showed cell viability of 85% and 56% resp. Since the mean relative tissue viability after exposure to the test substance was above 50% or 15% after resp. 3 minutes or 1 hour exposure, it can be concluded that the test substance is not corrosive in the in vitro skin corrosion test.