Benzenemethanimine, .alpha.-phenyl-

Endpoint summary

Description of key information

The test substance is not sensitizing to the skin of guinea pigs in the GPMT test (OECD TG 404, GLP).

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The LLNA method was not established yet by the time the study was conducted.

Specific details on test material used for the study:

- Name of test material (as cited in study report): BPI (Benzophenone imine)
- Analytical purity: 94.8 %
- Lot/batch No.: 11/94 container 13
- Physical state: liquid, light yellow
- Storage condition of test material: refrigerator

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River GmbH, Wiga, Kisslegg, FRG
- Age at study initiation: young adult animals
- Weight at study initiation: 318 - 350 g
- Housing: 5 animals per cage in Makrolon type IV cages
- Diet: Kliba Labordiaet 341 (Klingentalmuehle AG, Kaiseraugst, Switzerland) ad libitum
- Water: ad libitum (tap water; about 2 g of ascorbic acid per 10 L water was added to the drinking water twice a week)
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24
- Humidity (%): 30 - 70
- Photoperiod (hrs dark / hrs light): 12 / 12 (6.00 pm - 6.00 am dark, 6.00 am - 6.00 pm light)

Route:

intradermal and epicutaneous

Vehicle:

olive oil

Concentration / amount:

Intradermal induction: 1%
Epicutaneous induction: 50%
Epicutaneous challenge: 25 %

Route:

epicutaneous, occlusive

Vehicle:

olive oil

Concentration / amount:

Intradermal induction: 1%
Epicutaneous induction: 50%
Epicutaneous challenge: 25 %

No. of animals per dose:

Test group: 10
control groups 1 and 2: 5

Details on study design:

RANGE FINDING TEST:
Amount applied: 2 x 2 cm filter paper strips were applied to the skin of the flanks under an occlusive dressing (the bandage consists of rubberized linen patohes 4 x 4 cm from Russka, test patch 5 x 5 cm of Idealbinde from Pfälzische Verbandstoff-Fabrik, and Fixomull Stretch (adhesive fleece) from Beiersdorf AG). The test filter paper strip was soaked in the test substance formulation; thus, the animals were exposed to about 0.15 g of the test substance formulation.
Exposure period: The test substance was applied 2 times for 24 hours within a period of 96 hours in order to detect nonspecific phenomena that are not caused by a sensitization reaction but could possibly be attributed to a shift in the irritation threshold.
Site of application: flank, respective on the same area
Number of test animals: 4 or 8 per test concentration
Readings: about 24 and 48 h after the beginning of application

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2 (intradermal and epicutaneous)
- Exposure period: intradermal: unspecified, epicutaneous: 48 hours
- Test group:
Intradermal induction:
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 test substance formulation
C) back row: 2 injections each of 0.1 ml Freund's adjuvant/0.9% aqueous NaCl-solution (1 : 1) with test substance

Epicutaneous induction:
Epicutaneous induction was carried out one week after intradermal induction.
2 x 4 cm filter paper strips were applied to the skin of the shoulder under an occlusive dressing (the bandage consists of rubberized linen patches 4 x 6 cm from Russka and Fixomull Stretch (adhesive fleece) from Beiersdorf AG). The filter paper strip was soaked in the test substance formulation; thus, the animals were exposed to about 0.3 g of the test substance formulation.

- Control groups 1 and 2: The animals were treated analogously to the test group but without test substance.
- Site: shoulder
- Concentrations: intradermal: 1%, epicutaneous: 50%

B. CHALLENGE EXPOSURE (Challenge 21 days after intradermal induction)
- No. of exposures: 1
- Exposure period: 24 hours
- Test group:
2 x 2 cm filter paper strips were applied to the skin of the flank under an occlusive dressing (the bandage consists of rubberized linen patches 4 x 4 cm from Russka, test patch 5 x 5 cm of Idealbinde from Pfälzische Verbandstoff-Fabrik, and Fixomull Stretch (adhesive fleece) from Beiersdorf AG). The test filter paper strip was soaked in the test substance formulation; thus the animals were exposed to about 0.15 g of the test substance formulation. Right flank: 25% test substance in olive oil DAB 10; left flank: olive oil DAB 10
- Control group 1: Right flank: treatment with 25% test substance in olive oil DAB 10, left flank: olive oil DAB 10
- Control group 2: Treatment with olive oil DAB 10 only.
- Site: intact flank
- Concentration: 25%
- Evaluation (hr after challenge): 24 and 48

Positive control substance(s):

no

Remarks:

A positive control (reliability check) with a known sensitizer is not included in this study. However, the results of the latest study with Alpha-Hexylcinnamaldehyde techn. 85% showed that the test system was able to detect sensitizing compounds.

Positive control results:

A positive control (reliability check) with a known sensitizer was not included in this study. However, the results of the latest positive control study with Alpha-Hexylcinnamaldehyde techn. 85% showed that the test system was able te detect sensitizing compounds under the laboratory conditions chosen.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25%

No. with + reactions:

0

Total no. in group:

10

Reading:

1st reading

Hours after challenge:

24

Group:

other: control group 1

Dose level:

25%

No. with + reactions:

0

Total no. in group:

5

Reading:

2nd reading

Hours after challenge:

48

Group:

other: control group 1

Dose level:

25%

No. with + reactions:

0

Total no. in group:

5

Reading:

1st reading

Hours after challenge:

24

Group:

other: control group 2

Dose level:

vehicle

No. with + reactions:

0

Total no. in group:

5

Reading:

2nd reading

Hours after challenge:

48

Group:

other: control group 2

Dose level:

vehicle

No. with + reactions:

0

Total no. in group:

5

After the intradermal induction well-defined erythema and slight edema were observed at the injection sites of control group animals and test group animals at which only Freund's adjuvant / 0.9% aqueous NaCl-solution (1:1) was applied. Injection of a 1% test substance preparation in olive oil DAB 10 or in Freund's adjuvant / 0.9% aqueous NaCl-solution (1:1) caused well-defined erythema and slight edema in the test group animals. The injection sites of the central group animals which were applied with olive oil DAB 10 exhibited well-defined erythema.

After the percutaneous induction with a 50% test substance preparation incrustation, partially open (caused by the intradermal induction) could be observed in addition to well-defined erythema and slight edema in the test group animals.

The animals of control group 1 and 2, which were applied with olive oil DAB 10 showed the same skin reactions as the test group animals.

After the challenge with a 25% test substance preparation no skin reaction could be observed neither in control group 1 nor in the test group.

Olive oil DAB 10, which was applied as a vehicle to all animals did not cause any skin reaction.

The individual body weights can be derived from the respective tables in the Annex.

The evaluation of the results is based on the criteria of the EEC Directive 93/21 for the l8th Amendment of the Directive 67/548 EEC (Publication No. L 110 A, May 4th,1993).

The number of animals sensitized is primarily taken into account in the evaluation. The control animals are used to rule out a substance-induced primary skin irritation.

The findings obtained 24 hours after the removal of the patch are taken into account for the determination of the sensitization rate.

The positive control with Alpha-Hexylcinnamaldehyde techn. 85% showed that the test system was able to detect sensitizing compounds under the laboratory conditions chosen. Based on the results of the study under the test conditions chosen and taking the above cited evaluation criteria into account BPI does not have a sensitizing effect on the skin of the guinea pig in the Maximization Test.

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results of the study under test conditions chosen, the test substance does not have a sensitizing effect on the skin of the guinea pig in the Maximization Test.

Executive summary:

The test substance was tested for its sensitizing effect on the skin of the guinea pig in the Maximization Test based on the method of Magnusson and Kligmann and according to OECD 406 and GLP.

The intradermal induction with 1% test substance preparations caused slight to well-deined signs of irritation in the test group animals. After percutaneous induction with a 50% test substance preperation incrustation, partially open (caused by the intradermal induction) could be observed in addition to well-defined erythema and slight edema in the test group animals. No skin reactions were observed after the challenge.

Based on the results of the study under test conditions chosen, the test substance does not have a sensitizing effect on the skin of the guinea pig in the Maximization Test.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information:

The test substance was tested for its sensitizing effect on the skin of the guinea pig in the Maximization Test based on the method of Magnusson and Kligmann and according to OECD 406 and GLP.

The intradermal induction with 1% test substance preparations caused slight to well-deined signs of irritation in the test group animals. After percutaneous induction with a 50% test substance preperation incrustation, partially open (caused by the intradermal induction) could be observed in addition to well-defined erythema and slight edema in the test group animals. No skin reactions were observed after the challenge. Based on the results of the study under test conditions chosen, the test substance does not have a sensitizing effect on the skin of the guinea pig in the Maximization Test.

Justification for classification or non-classification

Classification, Labelling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. No local reactions were observed in a guinea pig maximization test (OECD 406) . Therefore, the substance does not require classification as a skin sensitizer under Regulation (EC) No. 1272/2008, as amended for the thirteenth time in Regulation (EC) No. 2018/1480.