2-Cyclohexen-1-one, 3,4-dihydroxy-2,6,6-trimethyl-, sodium salt (1:1)

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant guideline study. Available as unpublished report. No restrictions, fully adequate for assessment.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River GmbH - Wiga, Sulzfeld, FRG
- Age at study initiation: Young adult animals
- Weight at study initiation: 296 - 365 g
- Housing: 5 animals per Makrolon, type IV cage with Granulat Typ 3/4 (staubfrei) bedding; SSNIFF
- Diet: Kliba Labordiät 341 (Kaninchen-Meerschweinchen-Haltungsdiät) ad libitum
- Water: tap water (with about 2 g of ascorbic acid per 10 L water) ad libitum.
- Acclimation period: 7 days

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

Route:

intradermal and epicutaneous

Vehicle:

water

Concentration / amount:

- Intradermal induction: 5%
- Epicutaneous induction: unchanged test substance
- Challenge: unchanged test substance

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

- Intradermal induction: 5%
- Epicutaneous induction: unchanged test substance
- Challenge: unchanged test substance

No. of animals per dose:

Test group: 20
Control group 1: 10

Details on study design:

PRETEST:
- For detecting a possible influence on irritating effects of previous intradermal treatment with Freund's adjuvant, animals pretreated with Freund's adjuvant / 0.9% aqueous NaCl-solution (1:1) each, in the same manner as intradermal induction about 3 weeks prior to the application of the test substance were used.
- 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 linenpatches 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 or test substance formulation; thus, the animals were exposed to about 0.15 g of the test substance or 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 per test concentration
- Readings: about 24 and 48 h after the beginning of application
- Assessment of the skin findings: According to Draize

INDUCTION EXPOSURE: Intradermal induction
- Injections for the test group: 6 intradermal injections in groups of two per animal
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
- Injections for controls: The animals were given the same injections (A, B, C) but without test substance, only with the formulating agent.
- Site of application: shoulder
- Readings: 24 h after the beginning of application
- Assessment of the skin findings: analogous to the pretest

INDUCTION EXPOSURE: Percutaneous induction
- Percutaneous induction was carried out one week after intradermal induction
- Amount applied: 2 x 4 cm filter paper strips were applied to the skin of the shoulder under an occlusive dressing (the bandage consists of rubberized linenpatches 6 x 4 cm from Russka and Fixomulle Stretch (adhesive fleece) from Beiersdorf AG). The filter paper strip was soaked in the test substance; thus, the animals were exposed to about 0.3 g of the test substance. The controls were not treated, since the test substance was applied unchanged and thus no solvent was used.
- Duration of exposure : 48 hour
- Site of application: shoulder, same area as in the case of the previous intradermal application
- Readings: 48 h after the beginning of application
- Assessment of the skin findings: analogous to the pretest

CHALLENGE EXPOSURE
- Challenge: 21 days after intradermal induction
- Amount applied : 2 x 2 cm filter paper strips were applied to the skin of the flank under an occlusive dressing (the bandage consists of rubberized linenpatches 4 x 4 cm from Russka, test patch 5 x 5 cm of Idealbinde from Pfälzische Verbandstoff-Fabrik, and Fixomull(D 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. Treatment of the test group and of control group 1 with the unchanged test substance.
- Duration of exposure: 24 hours
- Site of application: intact flank
- Readings: 24 and 48 h after the removal of the patch
- Assessment of the skin findings: analogous to the pretest

Positive control substance(s):

yes

Remarks:

1-chloro-2,4-dinitrobenzene

Positive control results:

The positive control with 1-chloro-2,4-dinitrobenzene 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:

unchanged test substance

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: unchanged test substance. No with. + reactions: 0.0. Total no. in groups: 20.0.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

unchanged test substance

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: unchanged test substance. No with. + reactions: 0.0. Total no. in groups: 10.0.

PRETEST
- In the preliminary test after two 24-hour percutaneous occlusive applications within 96 hours the unchanged test substance was found to be non-irritant.

MAIN TEST
-After the intradermal induction well-defined erythema and slight edema could be observed at the injection sites of the control group animals and test group animals at which only Freund's adjuvant/0.9% aqueous NaCl-solution 1:1) was applied. Injection of the test substance preparation in 0.9% aqueaus NaCl-solution caused very slight erythema in 13 test group animals and well-defined erythema in 7 out of 20 test group animals, at which 3 out of these 7 test group animals additionally showed very slight edema. After injection of the test substance preparation in Freunds adjuvant/0.9% aqueous NaCl-solutian 1:1) the test group animals exhibited well-defined erythema and slight edema.The control group animals injected with 0.9% aqueous NaCl-solution did not show any skin reaction.
- The percutaneous induction was only carried out in the test group animals, because the test substance was applied unchanged and thus na solvent was used. Incrustation partially open (caused by the intradermal inductian) could be observed in addition to well defined erythema and slight edema.
- The challenge with the unchanged test substance did not cause any skin reactions neither in the test group animals nor in the animals of control group.

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Based on the results of the study under the 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 20 guinea pigs in the Maximization Test performed according to OECD guideline 406 and in compliance with GLP. The intradermal induction with the 5% test substance preparations caused very slight to well-defined signs of irritation in the test group animals. After percutaneous induction (one week after intradermal induction) with the unchanged test substance incrustation, partially open (caused by the intradermal induction) in addition to well-defined erythema and slight edema could be observed in the test group animals. The challenge (3 weeks after intradermal induction) with the unchanged test substance did not cause any skin reactions neither in the test group animals nor in the animals of the control group. Based on the results of the study under the 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)

Additional information:

The test substance was tested for its sensitizing effect on the skin of 20 guinea pigs in the Maximization Test performed according to OECD guideline 406 and in compliance with GLP (BASF 1994). The intradermal induction with the 5% test substance preparations caused very slight to well-defined signs of irritation in the test group animals. After percutaneous induction (one week after intradermal induction) with the unchanged test substance incrustation, partially open (caused by the intradermal induction) in addition to well-defined erythema and slight edema could be observed in the test group animals. The challenge (3 weeks after intradermal induction) with the unchanged test substance did not cause any skin reactions neither in the test group animals nor in the animals of the control group. Based on the results of the study under the test conditions chosen the test substance does not have a sensitizing effect on the skin of the guinea pig in the Maximization Test.

Migrated from Short description of key information:
The test substance is considered to be not sensitising to the skin in a OECD 406 guideline study (GLP) .

Justification for selection of skin sensitisation endpoint:
One skin sensitisation study is available. This study is adequate for covering this endpoint.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the results obtained in the skin sensitisation test (according to OECD guideline 406), classification for skin sensitisation is not warranted in accordance with EU Directive 67/548 (DSD) and EU Classification, Labeling and Packaging of Substances and Mixtures (CLP) Regulation No. 1272/2008.