3-(amidinothio)propionic acid

Endpoint summary

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:

1999-09-13 to 1999-11-05

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and guideline compliant study.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

(1992)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Version / remarks:

(1996)

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

in vivo skin sensitisation study with gunea pig was already available.

Species:

guinea pig

Strain:

other: Hsd Poc: DH (SPF)

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH, Borchen, Germany
- Age at study initiation: young adult
- Weight at study initiation: 341 - 400 g
- Housing: in groups of 5 animals (stainless steel wire mesh cages with plastic-coated grating, floor area: 3000 cm²)
- Diet: ad libitum, standard laboratory diet (Provimi Kliba SA, Kaiseraugst, Switzerland)
- Water: ad libitum, tap water
- Acclimation period: 6 days before the beginning of the study in the laboratory for dermal toxicity

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 - 25
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12-12

Route:

intradermal and epicutaneous

Vehicle:

other: Tylose CB 30.000 in water

Concentration / amount:

Intradermal induction: 5 %
Epicutaneous induction: 25 %
Challenge: 10 %

Route:

epicutaneous, occlusive

Vehicle:

other: Tylose CB 30.000 in water

Concentration / amount:

Intradermal induction: 5 %
Epicutaneous induction: 25 %
Challenge: 10 %

No. of animals per dose:

5 per control group; 10 per test group

Details on study design:

RANGE FINDING TESTS: Intradermal and epicutaneous range finding study
Two 24-hour epicutaneous occlusive applications within 96 hours were performed. The minimum irritant concentration was found to be a 25 % test substance preparation in 1 % Tylose CB 30.000 in aqua bidest. The maximum non-irritant concentration was found to be a 10 % test substance preparation in 1 % Tylose CB 30.000 in aqua bidest.
Applicability: It was possible to inject a 5 % test substance preparation in 1 % Tylose CB 30.000 in aqua bidest. or in Freund's adjuvant /0.9 % aqueous NaCl-solution (1 : 1) with a syringe. The concentration was well-tolerated locally and systemically.

MAIN STUDY
A. INDUCTION EXPOSURE (INTRADERMAL)
- No. of exposures: 6
- Test groups: 3 different injections were given
A) front row: 2 injections each of 0.1 mL Freund's adjuvant without test substance emulsified with 0.9 % aqueous NaCl-solution in a ratio of 1: 1
B) middle row: 2 injections each of 0.1 mL of a test substance formulation in an appropriate vehicle at the selected concentration
C) back row: 2 injections each of 0.1 mL Freund's adjuvant /0.9 % aqueous NaCl-solution (1: 1) with test substance at the selected concentration.
- Control group: 3 different injections were given
A) front row: 2 injections each of 0.1 mL Freund's adjuvant without test substance emulsified with 0.9 % aqueous NaCl-solution in a ratio of 1: 1
B) middle row: 2 injections each of 0.1 mL of the undiluted vehicle
C) back row: 2 injections each of 0.1 mL of a 50 % formulation of the vehicle without test substance emulsified with Freund's adjuvant* /0.9 % aqueous NaCl-solution (1:1)
- Site: Shoulder
- Frequency of applications: once
- Duration: 7 days
- Concentrations: 5 % of test substance in 1 % Tylose CB 30.000 in aqua bidest.

B. INDUCTION EXPOSURE (EPICUTANEOUS)
- No. of exposures: 1
- Exposure period: 48 hours
- Test groups: 1 mL of test substance formulation on gauze patches under an occlusive dressing
- Control group: treated analogously but with vehicle only
- Site: Shoulder
- Frequency of applications: once
- Duration: 14 days
- Concentrations: 25 %


C. CHALLENGE EXPOSURE
- No. of exposures: 3
- Day(s) of challenge: 14, 21 and 43 days after epicutaneous application
- Exposure period: 24 hours
- Test groups: 0.5 mL of test substance formulation on gauze patches under an occlusive dressing

1st challenge
The test group and control group 1 were treated with the test substance formulation. Additionally, 1 % Tylose in aqua bidest. was applied as a vehicle control. Control group 2 only received 1 % Tylose in aqua bidest.

2nd and 2rd challenge
Treatment of the test group and of control groups 1 and 2 with the test substance formulation. Analogous to the 1st challenge 1 % Tylose CB 30.000 in aqua bidest. was applied as a vehicle control.

- Site: left and right flank
- Concentrations: 10 %
- Evaluation (hr after challenge): 24 and 48 hours after removal of the patch.

Positive control substance(s):

no

Remarks:

A positive control (reliability check) with a known sensitizer is not included in this study. However, a separate study is performed twice a year in the laboratory to demonstrate sensitivity of the test system.

Positive control results:

The positive controls with 2-Mercaptobenzothiazole and Formaldehyde solution (min. 36.5 % for Analysis Reag. ACS, stabilised by ca. 10 % methanol) showed that the test system was able to detect sensitizing compounds under the laboratory conditions chosen.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

10 %

No. with + reactions:

8

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 10 %. No with. + reactions: 8.0. Total no. in groups: 10.0.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

10 %

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 10 %. No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

10 %

No. with + reactions:

8

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 10 %. No with. + reactions: 8.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

10 %

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 10 %. No with. + reactions: 0.0. Total no. in groups: 5.0.

Reading:

other: 1st rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

10 %

No. with + reactions:

8

Total no. in group:

10

Remarks on result:

other: Reading: other: 1st rechallenge. . Hours after challenge: 24.0. Group: test group. Dose level: 10 %. No with. + reactions: 8.0. Total no. in groups: 10.0.

Reading:

other: 1st rechallenge

Hours after challenge:

24

Group:

negative control

Dose level:

10 %

No. with + reactions:

1

Total no. in group:

5

Remarks on result:

other: Reading: other: 1st rechallenge. . Hours after challenge: 24.0. Group: negative control. Dose level: 10 %. No with. + reactions: 1.0. Total no. in groups: 5.0.

Reading:

other: 1st rechallenge

Hours after challenge:

48

Group:

test chemical

Dose level:

10 %

No. with + reactions:

4

Total no. in group:

10

Remarks on result:

other: Reading: other: 1st rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 10 %. No with. + reactions: 4.0. Total no. in groups: 10.0.

Reading:

other: 1st rechallenge

Hours after challenge:

48

Group:

negative control

Dose level:

10 %

No. with + reactions:

1

Total no. in group:

5

Remarks on result:

other: Reading: other: 1st rechallenge. . Hours after challenge: 48.0. Group: negative control. Dose level: 10 %. No with. + reactions: 1.0. Total no. in groups: 5.0.

Reading:

other: 2nd rechallenge

Hours after challenge:

24

Group:

test chemical

Dose level:

10 %

No. with + reactions:

6

Total no. in group:

10

Remarks on result:

other: Reading: other: 2nd rechallenge. . Hours after challenge: 24.0. Group: test group. Dose level: 10 %. No with. + reactions: 6.0. Total no. in groups: 10.0.

Reading:

other: 2nd rechallenge

Hours after challenge:

24

Group:

negative control

Dose level:

10 %

No. with + reactions:

1

Total no. in group:

5

Remarks on result:

other: Reading: other: 2nd rechallenge. . Hours after challenge: 24.0. Group: negative control. Dose level: 10 %. No with. + reactions: 1.0. Total no. in groups: 5.0.

Reading:

other: 2nd rechallenge

Hours after challenge:

48

Group:

test chemical

Dose level:

10 %

No. with + reactions:

6

Total no. in group:

10

Remarks on result:

other: Reading: other: 2nd rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 10 %. No with. + reactions: 6.0. Total no. in groups: 10.0.

Reading:

other: 2nd rechallenge

Hours after challenge:

48

Group:

negative control

Dose level:

10 %

No. with + reactions:

1

Total no. in group:

5

Remarks on result:

other: Reading: other: 2nd rechallenge. . Hours after challenge: 48.0. Group: negative control. Dose level: 10 %. No with. + reactions: 1.0. Total no. in groups: 5.0.

Induction

After the intradermal induction intense erythema and swelling were observed at the injection sites of all control group animals and all test group animals at which only Freund's adjuvant / 0.9 % aqueous NaCl-solution (1:1) was applied. After the injection of a 5 % test substance preparation in 1 % Tylose GB 30.000 in aqua bidest. all test group animals exhibited moderate and confluent erythema. Injections of a 5 % test substance preparation in Freund's adjuvant / 0.9% aqueous NaCl-solution (1:1) caused intense erythema and swelling in all test group animals. The control group animals, injected with 1 % Tylose CB 30.000 in aqua bidest. (vehicle) did not show any skin reactions. A 50 % formulation of 1 % Tylose GB 30.000 in aqua bidest. with Freund's adjuvant / 0.9 % aqueous NaCl-solution (1:1) caused intense erythema and swelling in all control group animals. The epicutaneous induction with a 25 % test substance preparation in 1 %Tylose GB 30.000 in aqua bidest. led to incrustation, partially open (caused by the intradermal induction), intense erythema in addition to swelling in all test group animals. The control group animals, which were treated with 1 % Tylose GB 30.000 in aqua bidest. (vehicle) exhibited incrustation, partially open (caused by the intradermal induction) in addition to moderate and confluent erythema with swelling.

Challenge

A 10 % test substance preparation in 1 % Tylose CB 30.000 in aqua bidest. caused the following skin reactions:

Reading at 24 hours after removal of the patches:

- no skin findings in all animals of control group 1

- discrete or patchy erythema in 2 out of 10 test group animals

- moderate and confluent erythema in 1 out of 10 test group animals

- moderate and confluent erythema and swelling in 4 out of 10 test group animals

- intense erythema and swelling in 1 out of 10 test group animals

Reading at 48 hours after removal of the patches:

- no skin findings in all animals of control group 1

- discrete or patchy erythema in 1 out of 10 test group animals

- discrete or patchy erythema and scaling in 1 out of 10 test group animals

- moderate and confluent erythema and scaling in 3 out of 10 test group animals

- moderate and confluent erythema, swelling and scaling in 3 out of 10 test group animals

1 % Tylose CB 30.000, which was applied as a vehicle control to all animals, did not cause any skin reactions.

1st rechallenge

A 10 % test substance preparation in 1 % Tylose CB 30.000 in aqua bidest. the following skin reactions could be observed:

Reading at 24 hours after removal of the patches:

- no skin findings in all animals of control group 2

- discrete or patchy erythema in 1 out of 5 animals of control group 1

- discrete or patchy erythema in 5 out of 10 test group animals

- moderate and confluent erythema and swelling in 3 out of 10 test group animals

Reading at 48 hours after removal of the patches:

- no skin findings in all animals of control group 2

- discrete or patchy erythema in 1 out of 5 animals of control group 1

- discrete or patchy erythema in 3 out of 10 test group animals

- moderate and confluent erythema and scaling in 1 out of 10 test group animals

1 % Tylose CB 30.000, which was applied as a vehicle control to all animals, did not cause any skin reactions.

2nd rechallenge

A 10 % test substance preparation in 1 % Tylose CB 30.000 in aqua bidest. the following skin reactions could be observed:

Reading at 24 hours after removal of the patches:

- no skin findings in all animals of control group 2

- discrete or patchy erythema in 1 out of 5 animals of control group 1

- discrete or patchy erythema in 1 out of 10 test group animals

- moderate and confluent erythema in 4 out of 10 test group animals

- moderate and confluent erythema and swelling in 1 out of 10 test group animals

Reading at 48 hours after removal of the patches:

- no skin findings in all animals of control group 2

- discrete or patchy erythema in 1 out of 5 animals of control group 1

- discrete or patchy erythema in 1 out of 10 test group animals

- moderate and confluent erythema in 2 out of 10 test group animals

- intense erythema and swelling in 3 out of 10 test group animals

1 % Tylose CB 30.000, which was applied as a vehicle control to all animals, did not cause any skin reactions.

Interpretation of results:

sensitising

Remarks:

Migrated information

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Additional information:

In a dermal sensitisation study according to OECD guideline 406, the test substance was applied to the intact skin of 10 female guinea pigs as well as of 5 control animals (BASF SE, 30H0464/982239, 2000). The maximisation method was used. For the intradermal induction phase, three pairs of injections were made in the scapular region with a test substance dilution of 5 %. One week later the scapular area was epicutaneously treated with 1 mL of a 25 % dilution. Three challenges were performed with 0.5 mL of a 10 % dilution 14, 21 and 43 days after the topical induction. Topical induction and challenges were performed under occlusive conditions. Readings were performed 24 and 48 hours after treatment.

The intradermal induction with a 5 % test substance preparation in Freund's adjuvant / 0.9 % aqueous NaCl-solution (1:1) caused intense erythema and swelling in all test group animals. Moderate and confluent erythema could be observed after injection of a 5 % test substance preparation in 1 % Tylose CB 30.000 in aqua bidest. After the epicutaneous induction with a 25 % test substance preparation, incrustation, partially open (caused by the intradermal induction) could be observed in addition to intense erythema and swelling in all test group animals. Three challenges were performed 14, 21 and 43 days after the epicutaneous induction. After the challenges with a 10 % test substance preparation in 1 % Tylose CB 30.000 in aqua bidest., discrete or patchy erythema to intense erythema with swelling and scaling were observed in test group animals. Discrete or patchy erythema was noted in one control group 1 animal (after the 1st and 2nd rechallenge). In the challenge and 1st rechallenge 8 out of 10 animals showed positive skin reactions. In the 2nd rechallenge 6 out of 10 animals showed a positive reaction.

Based on the results of this study, it was concluded that the test substance has a sensitizing effect on the skin of the guinea pig in the maximization test under the test conditions chosen.

Migrated from Short description of key information:
In a guinea-pig maximisation test, the test substance was found to be sensitising to the skin (BASF SE, 2000).

Justification for selection of skin sensitisation endpoint:
GLP and guideline compliant study.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The available experimental test data are reliable and suitable for classification purposes. As a result the substance needs to be classified and labelled as skin sensitising cat. 1, H317 (May cause an allergic skin reaction) under Regulation (EC) No 1272/2008, as amended for the seventh time in Regulation (EU) No 2015/1221.