Sodium N-methyltaurinate

Endpoint summary

Description of key information

Sodium N-methyltaurinate is corrosive to the skin and eyes.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Reference 1

Endpoint:

skin irritation / corrosion, other

Remarks:

OECD 404

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1985

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Name of test material (as cited in study report): N-methylamino-ethansufonsaures Natrium (German)/sodium N-methylamino ethanesulfonate
Physical state: dehydrated
Composition:
- 76-84 % sodium N-methylamino ethanesulfonate
- 6-8 % sodium methylimino-di-ethanesulfonate
- 4-6 % sodium hydroxyethanesulfonate
- 1-2 % sodium hydroxide
- 1-3 % sodium sulfate
- 0-0.5 % sodium sulfite

Species:

rabbit

Strain:

New Zealand White

Type of coverage:

semiocclusive

Preparation of test site:

shaved

Vehicle:

physiological saline

Controls:

no

Amount / concentration applied:

500 mg

Duration of treatment / exposure:

4 h

Observation period:

0.5-1 h, 24 h, 48 h, 72 h, 7 d, 14 d

Number of animals:

3

Irritation parameter:

edema score

Basis:

mean

Time point:

other: 30 - 60 min, 24 h

Score:

1

Max. score:

4

Reversibility:

fully reversible within: 24 h

Remarks on result:

probability of weak irritation

Irritation parameter:

erythema score

Basis:

mean

Time point:

other: 30-60 min to 7 days

Score:

>= 1 - <= 3

Max. score:

4

Reversibility:

fully reversible within: 14 d

Remarks on result:

probability of mild irritation

Interpretation of results:

Category 1C (corrosive) based on GHS criteria

Conclusions:

Sodium N-methyltaurinate is shown to be corrosive to the skin of New Zealand White rabbits.

Executive summary:

The guideline study on skin irritation / corrosion of sodium N-methyltaurinate was conducted according to OECD 404 using New Zealand White rabbits. The study reports that the application of 500 mg sodium N-methyltaurinate on shaved skin (semiocclusive coverage) with a residence time of 4 h results in edema and erythema. Therefore, it can be concluded that sodium N-methyltaurinate is corrosive to the skin and has to be classified as skin corrosive category 1C.

Reference 2

Endpoint:

skin corrosion: 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

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Version / remarks:

OECD Guideline for the Testing of Chemicals No. 435: In Vitro Membrane Barrier Test Method for Skin Corrosion, 19 July 2006

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Name: N-Methyltaurin 62
Batch No.: VSMT62lyy0020615
CAS No.: 4316-74-9
Chemical Name: Sodium N-methyltaurinate
Aggregate State at RT: liquid
Storage Conditions: room temperature
Active Components: 62 % solution of sodium N-Methyltaurinate
Stability: stable
Expiry Date: 06/2017
Safety Precautions: The routine hygienic procedures were sufficient to assure personnel health and safety.

Test system:

artificial membrane barrier model

Remarks:

In Vitro Membrane Barrier Test (CORROSITEX™ Assay)

Justification for test system used:

Justification for the Selection of the Test System: The CORROSITEX™ Assay is a standardized, quantitative in vitro test for skin corrosivity and has been validated by the ECVAM for testing acids, bases and their derivatives. The bio-barrier membrane is constructed to have physico-chemical properties similar to rat skin.
Justification for the Selection of the Test Method: This in vitro method is permitted by the UN GHS tiered testing and evaluation strategy for the assessment and classification of skin corrosivity. Substances classified as non-corrosive shall undergo additional testing in accordance with the tiered testing strategy.

Vehicle:

unchanged (no vehicle)

Details on test system:

The test was carried out with the CORROSITEX™ Assay Kit (Invitro International; Irvine, CA 92614, Lot No.: CT 120314).
Prior to testing, the test substance was verified to be compatible with the COOROSITEX™ Assay.
The test was performed on a total of seven BIOBARRIERS (four BIOBARRIERS for the test item; one each for the positive and negative control and one as colour control).

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

The liquid test item was applied undiluted. 500 μL of the test item were placed directly atop the BIOBARRIER.

Number of replicates:

4

Irritation / corrosion parameter:

penetration time (in minutes)

Run / experiment:

Replicate 1

Value:

30.62

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Colour change: Yes; Consistency change: No.

Irritation / corrosion parameter:

penetration time (in minutes)

Run / experiment:

Replicate 2

Value:

30.67

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Colour change: Yes; Consistency change: No.

Irritation / corrosion parameter:

penetration time (in minutes)

Run / experiment:

Replicate 3

Value:

27.3

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Colour change: Yes; Consistency change: No.

Irritation / corrosion parameter:

penetration time (in minutes)

Run / experiment:

Replicate 4

Value:

30.77

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: Colour change: Yes; Consistency change: No.

Irritation / corrosion parameter:

penetration time (in minutes)

Run / experiment:

Positive control

Value:

18.05

Negative controls validity:

not applicable

Positive controls validity:

not applicable

Remarks on result:

other: Colour change: Yes; Consistency change: No.

Irritation / corrosion parameter:

penetration time (in minutes)

Run / experiment:

Negative control

Value:

74.88

Negative controls validity:

not applicable

Positive controls validity:

not applicable

Remarks on result:

other: Colour change: Yes; Consistency change: No.

Other effects / acceptance of results:

Replicates 1-4: The mean time required to activate the chemical detection system was 29.84 ± 1.69 min.

Interpretation of results:

Category 1B (corrosive) based on GHS criteria

Conclusions:

62 % sodium N-methyltaurinate solution is shown to activate the chemical detection system between > 3 - 60 min (mean time: 29.84 ± 1.69 min) in an In Vitro Membrane Barrier Test (CORROSITEX™ Assay), resulting in the classification as skin corrosive 1B.

Executive summary:

The guideline study on skin irritation / corrosion of 62 % sodium N-methyltaurinate solution was carried out according to OECD 435 using an In Vitro Membrane Barrier Test (CORROSITEX™ Assay). The study reports that the mean time to activate the chemical detection system is between > 3 - 60 min (29.84 ± 1.69 min) for the test substance. Therefore, 62 % sodium N-methyltaurinate solution should be classified as skin corrosive category 1B.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (corrosive)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irritating)

Additional information

Skin irritation/corrosion:

According to the OECD 404 guideline study on New Zealand rabbits, sodium N-methyltaurinate is classified as skin corrosive category 1C. The same study on a 35 -37 % aqueous solution of sodium N-methyltaurinate is reported to be neither irritating nor corrosive to skin. The two in vitro guideline studies according to OECD 435 for 40 % and 62 % aqueous solutions of sodium N-methyltaurinate were carried out using an In Vitro Membrane Barrier Test (CORROSITEX™ Assay). According to the studies, both solutions are classified as skin corrosive category 1B.

Eye irritation/damage:

According to Regulation (EU) No. 1907/2006, Annex VII, the studies for this endpoint do not need to be conducted, because the substance is classified as skin corrosion (category 1). Sodium N-methyltaurinate is classified as skin corrosive category 1C (see above), leading to classification as serious eye damage (category 1) according to Regulation (EU) No. 1272/2008. According to two OECD 405 guideline studies on New Zealand White rabbits, both sodium N-methyltaurinate and a 35-37 % aqueous solution of sodium N-methyltaurinate are classified with eye damage category 1.

Justification for classification or non-classification

The OECD guideline studies on the irritation/corrosion properties of sodium N-methyltaurinate show that the substance is skin corrosive and needs to be classified for skin corrosion and eye damage.

Skin corrosion / irritation:

The in vitro studies on 40 % and 62 % aqueous solutions of sodium N-methyltaurinate according to OECD 435, In Vitro Membrane Barrier Test (CORROSITEX™ Assay), showed that both solutions have to be classified as skin corrosive category 1B. In addition, the OECD 404 guideline study on New Zealand rabbits on sodium N-methyltaurinate showed that the substance needs to be classified as skin corrosive category 1C.

In conclusion, the results of the in vivo study will be applied and sodium N-methyltaurinate has to be classified as skin corrosive category 1C.

Eye irritation endpoint:

According to Regulation (EU) No. 1907/2006, Annex VII, the studies for this endpoint do not need to be conducted, because the substance is classified as skin corrosion (category 1). Thus, the classification of sodium N-methyltaurinate as skin corrosive category 1C (see above) leads to classification as serious eye damage (category 1) according to Regulation (EU) No. 1272/2008.