Sodium N-lauroylsarcosinate

Endpoint summary

Description of key information

Skin sensitisation (EU Method B.6, GPMT): not sensitising

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

3 Jul - 31 Jul 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

(No reliability check included.)

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

yes

Remarks:

no reliability check included

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

A non-LLNA test is available that was performed prior to the current data requirements, stipulated in Regulation (EC) No 1907/2006. In accordance with the same Regulation, the data was included to avoid unnecessary testing.

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Supplied by David Hall Limited
- Age at study initiation: young adult (less than one year old)
- Weight at study initiation: 358-461 g
- Housing: The test comprised of 20 test group and 20 control group guinea pigs housed 5 to a cage and 6 dose ranging guinea pigs housed in a ninth cage. Each aluminium cage had a grid floor beneath which was a peat moss filled tray.
- Diet: The animals were fed on Special Diet Services FD1 guinea pig diet, supplemented with hay, ad libitum.
- Water: ad libitum
- Acclimation period: at least 9 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-21
- Humidity (%): 58
- Photoperiod (hrs dark / hrs light): 12/12

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

Main test:
Induction:
Intradermal: 0.05% (v/v)
Epicutaneous: 5 % (v/v)

Challenge:
5 % (v/v)

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

Main test:
Induction:
Intradermal: 0.05% (v/v)
Epicutaneous: 5 % (v/v)

Challenge:
5 % (v/v)

No. of animals per dose:

20 (control and test groups)
2 (preliminary test)

Details on study design:

RANGE FINDING TEST
A preliminary range finding test was carried out to assess suitable concentrations for injection and topical application on 4 previously untreated guinea pigs. Injections were in the shaved scapular region and topical application was on the shaved flanks. Two guinea pigs were subjected to intradermal injections and a further 2 guinea pigs were exposed to topical application of the test substance for 48 h at various concentrations.
Injections - 10%, 5%, 2% and 1% (v/v) in distilled water
Topical application - 10%, 5%, 2% and 1% (v/v) in distilled water
Injection responses were assessed 24, 48 and 72 h after injection. Responses to the topical application were assessed 24, 8 and 72 h after patch removal. Before challenging the test animals, a maximum non-irritant concentration of the test material was determined in a preliminary experiment on 2 dose ranging guinea pigs. The animals were pretreated at the induction phase with Freund's Complete Adjuvant only.
The test material was applied to the shaved flanks of the guinea pigs for 24 h at concentrations of 10%, 5%, 2% and 1% v/v (A.I) in distilled water under the same system used for the topical induction except that the patches were left in position for 24 h.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: Example: 2 (intradermal and epicutaneous, respectively)
- Exposure period: Example: single injection (intradermal) and 48 h (epicutaneous)
- Test groups:
Intradermal (3 pairs of injections):
Injection 1: 0.10 mL Freund's Complete Adjuvant
Injection 2: 0.10 mL test material
Injection 3: test substance 0.05% (v/v) in a 1:1 mixture (v/v) FCA/water
- Epicutaneous: test substance in water. Six days after the injection phase, the injection site of each of the test and control group animals was shaved again and then wetted with 10% aqueous SLS to provoke a mild inflammatory response to enhance the possibility of sensitisation.

- Control group:
Intradermal (3 pairs of injections):
Injection 1: 0.10 mL Freund's Complete Adjuvant
Injection 2: 0.10 mL water
Injection 3: a 1:1 mixture (v/v) FCA/water
- Epicutaneous: test substance in water. Six days after the injection phase, the injection site of each of the test and control group animals was shaved again and then wetted with 10% aqueous SLS to provoke a mild inflammatory response to enhance the possibility of sensitisation.

- Site: 4 x 6 cm across the scapular region
- Frequency of applications: 7 days
- Duration: Days 0-8
- Concentrations:: intradermal 0.05%, epicutaneous 5%.

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 20 (challenge)
- Exposure period: 24 h
- Test groups: test substance and vehicle
- Control group: test substance and vehicle
- Site: Example: right flank (test substance) and left flank (vehicle)
- Concentrations: 5%
- Evaluation (hr after challenge): 48 and 72 h

Positive control substance(s):

no

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

Induction 0.05 and 5%, Challenge: 5%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: Induction 0.05 and 5%, Challenge: 5%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

Challenge: 5%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: Challenge: 5%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

Induction 0.05 and 5%, Challenge: 5%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: Induction 0.05 and 5%, Challenge: 5%. No with. + reactions: 0.0. Total no. in groups: 20.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

Challenge: 5%

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: Challenge: 5%. No with. + reactions: 0.0. Total no. in groups: 20.0.

PRELIMINARY STUDY

Dose Ranging for Induction:

Severe irritation was noted at sites injected at concentrations of 10%, 5%, 2% and 1% (v/v) in distilled water. A concentration of 0.05% (v/v) in distilled water was selected for injection at induction.

Slight-moderate irritation was noted after 48 h topical exposure under occlusion at a concentration of 10% (v/v) in distilled water. No irritation was observed at 5 % (v/v) after 24 h. Therefore, a concentration of 5% (v/v) in distilled water was selected for topical application at induction.

Dose Ranging for Challenge:

Slight irritation was noted a concentration of 10% (v/v) in distilled water. A concentration of 5% (v/v) in distilled water was selected for challenge.

MAIN STUDY

Induction:

Moderate erythema was noted in test group animals and slight erythema was noted in control group animals.

Challenge:

No reactions were noted in test and control animals after challenge.

Body Weight:

Bodyweights were recorded at test commencement and on test completion. Body weight gains were within acceptable range.

Clinical Signs:

No clinical signs, except skin reactions induced by treatment, were noted at any time point during the study.

Interpretation of results:

other: CLP/EU GHS criteria not met, no classification required according to Regulation(EC) No. 1272/2008

Conclusions:

CLP: not classified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Discussion

Skin sensitisation

The skin sensitising properties of Sodium N-lauroylsarcosinate (CAS 137-16-6) were investigated in a Guinea pig maximisation test according to EU method B.6 under GLP conditions (Inversek Research International, 1987d).

A preliminary range finding test was conducted to determine suitable concentrations for the main study for the intradermal injection and the patch testing. In the main study, female Dunkin-Hartley guinea pigs (20/group) were induced on Day 0 with 3 pairs of intradermal injections of FCA, 0.1 mL of the test substance alone and 0.05% test substance in FCA/water. Epicutaneous induction was done by application of the test substance at 5% in water on Day 8. The negative control group was treated with FCA, water or water/FCA alone. Six days after the injection phase the injection site of each of the test and control group animals was shaved again and then wetted with 10% aqueous SLS to provoke a mild inflammatory response to enhance the possibility of sensitisation. Epicutaneous challenge exposure was conducted 20 days after the first induction for 24 h under occlusive conditions. Test substance was applied at a concentration of 5% on the right flank, and the vehicle was applied on the left flank, respectively. Evaluation of skin reactions was carried out 48 and 72 h after challenge. No positive control substance was included in the study.

Moderate erythema was noted in test group animals, and slight erythema was noted in control group animals after induction. At challenge, all test and vehicle control animals showed no skin reactions after 48 and 72 h. No changes in body weight were observed in any animal during the study period. No further clinical signs were noted at any time point during the study.

Thus, the available data on skin sensitisation do not provide evidence for sensitising properties of Sodium N-lauroylsarcosinate (CAS 137-16-6).

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available data on the skin sensitisation of Sodium N-lauroylsarcosinate (CAS 137-16-6) do not meet the criteria for classification according to Regulation (EC) No 1272/2008, and are therefore conclusive but nor sufficient for classification.