Zirconium, tetrakis(isobutyrato)-

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22th November 2005-17th February 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to OECD guideline with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

Tetrakis(isobutyrato)zirconium

EC Number:

619-635-5

Cas Number:

12567-73-6

Molecular formula:

Hill formula: C16H28O8Zr CAS formula: C16H28O8Zr

IUPAC Name:

Tetrakis(isobutyrato)zirconium

Constituent 2

Reference substance name:

Zirconium, tetrakis(isobutyrato)- (8CI)

IUPAC Name:

Zirconium, tetrakis(isobutyrato)- (8CI)

Details on test material:

- Name of test material (as cited in study report): Zirkonium-tetrakis(isobutyrato)
- Physical state: solid
- Analytical purity: 97.4 % (complexometric titration)
- Impurities (identity and concentrations): By-products:
toluene: ca. 2.1 %.
iso-butyric acid: ca. 0.5 %.
- Lot/batch No.: 02/05 (HK1005)
- Expiration date of the lot/batch: September 2006
- Storage condition of test material: Ambient temperature. Tightly closed. Storage under a nitrogen atmosphere, as the substance reacts with water.

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann, Gartenstrasse 27, D-33178 Borchen, Germany.
- Age at study initiation: Approximatly 5 - 7 weeks
- Weight at study initiation: 331 g to 400 g
- Housing: Group caging in plastic containers (46 cm x 105 cm x 36 cm), partly shaded, 6 (control group) or 11 (test substance group) animals per container
- Diet (e.g. ad libitum): Altromin Maintenance Diet No. 3122, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: Step 1: 12 days, Step 2: 5 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Step 1: Average of 22.0 °C, Step 2: Average of 21.4 °C
- Humidity (%): Step 1: Average of 62.2 %, Step 2: Average of 45.1 %
- Air changes (per hr): Approximatly 12/h.
- Photoperiod (hrs dark / hrs light): Only artificial light from 6.00 a.m. to 6.00 p.m.

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

other: acetone

Induction 2

Concentration / amount:

Step 1 and step 2:
Group C: Negative control:
Induction exposure:
- i.d. exposure: acetone
- epicutaneous exposure: acetone
Challenge exposure:
- left flank: TS, 25 % (w/v) in acetone
- right flank: acetone

Group H: Test substance
Induction exposure:
- i.d. exposure: TS, 0.5 % (w/v) in acetone
- epicutaneous exposure: TS, 25 % (w/v) in acetone
Challenge exposure:
- left flank: TS, 25 % (w/v) in acetone
- right flank: acetone

TS = test substance

Challenge

Challenge 1

Route:

epicutaneous, open

Vehicle:

other: acetone

Challenge 2

Concentration / amount:

Step 1 and step 2:
Group C: Negative control:
Induction exposure:
- i.d. exposure: acetone
- epicutaneous exposure: acetone
Challenge exposure:
- left flank: TS, 25 % (w/v) in acetone
- right flank: acetone

Group H: Test substance
Induction exposure:
- i.d. exposure: TS, 0.5 % (w/v) in acetone
- epicutaneous exposure: TS, 25 % (w/v) in acetone
Challenge exposure:
- left flank: TS, 25 % (w/v) in acetone
- right flank: acetone

TS = test substance

No. of animals per dose:

In both steps: 10 animals for the test substance group and 5 animals for the control group.
One additional animal per group was kept and administered under the same conditions as the other animals of the respective group. Findings on the spare animals were only incorporated into this report if other animals of the test substance group or of the control group would have died spontaneously. Otherwise, the skin reactions of these animals were not used for the interpretation of the results.

Details on study design:

RANGE FINDING TESTS: In both steps the test substance concentrations were derived from the results of a preliminary test: 0.5 % (w/v) in acetone for the intradermal induction 25 % (w/v) in acetone for the epicutaneous induction and 25 % (w/v) in acetone for the challenge exposure. 25% (w/v) in acetone was the highest technically feasible test substance concentration.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures:
- Exposure period:
- Test groups: yes
- Control group: yes
- Site: interscapular region (intradermal induction exposure)
- Frequency of applications:
- Duration: 48 hours (epidutaneous induction exposure)
- Concentrations: TS, 0.5 % (w/v) in acetone

B. CHALLENGE EXPOSURE
- No. of exposures:
- Day(s) of challenge:
- Exposure period: 24 hours
- Test groups: yes
- Control group: yes
- Site: left flanks
- Concentrations: TS, 25 % (w/v) in acetone
- Evaluation (hr after challenge): The application sites were examined 24 and 48 hours after the end of the epicutaneous challenge exposures (blind reading of test and control animals)

OTHER:

Challenge controls:

7/10 animals (70 %) represented the net rate of animals sensitised by "HEXYL CINNAMIC ALDEHYDE".
The results prove the sensitivity of the strain of animals used and the reliability of the experimental technique.

Positive control substance(s):

yes

Remarks:

HEXYL CINNAMIC ALDEHYDE

Results and discussion

In vivo (non-LLNA)

Results

Results 1

Reading:

other: Skin reactions 24 hours after the intradermal and 24 hours after the end of the epicutaneous induction exposures and 24 and 48 hours after the end of the epicutaneous challenge exposure

Group:

negative control

No. with + reactions:

10

Total no. in group:

10

Clinical observations:

Score 3: severe erythema and/or oedema

Remarks on result:

other: see Remark

Remarks:

Reading: other: Skin reactions 24 hours after the intradermal and 24 hours after the end of the epicutaneous induction exposures and 24 and 48 hours after the end of the epicutaneous challenge exposure. Group: negative control. No with. + reactions: 10.0. Total no. in groups: 10.0. Clinical observations: Score 3: severe erythema and/or oedema.

Results 2

Reading:

other: Skin reactions 24 hours after the intradermal and 24 hours after the end of the epicutaneous induction exposures and 24 and 48 hours after the end of the epicutaneous challenge exposure.

Group:

test chemical

No. with + reactions:

20

Total no. in group:

20

Clinical observations:

Score 3: severe erythema and/or oedema

Remarks on result:

other: see Remark

Remarks:

Reading: other: Skin reactions 24 hours after the intradermal and 24 hours after the end of the epicutaneous induction exposures and 24 and 48 hours after the end of the epicutaneous challenge exposure.. Group: test group. No with. + reactions: 20.0. Total no. in groups: 20.0. Clinical observations: Score 3: severe erythema and/or oedema.

Results 3

Reading:

other: challenge

Group:

negative control

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

Score 0: no reactions

Remarks on result:

other: Reading: other: challenge. Group: negative control. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: Score 0: no reactions.

Results 4

Reading:

other: challenge

Group:

test chemical

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

Score 0: no reactions

Remarks on result:

other: Reading: other: challenge. Group: test group. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: Score 0: no reactions.

Any other information on results incl. tables

All animals survived till the end of the study.

No statistically significant differences in the mean body weights between the animals of the test substance groups and those of the control group on Days 0 (step 1 and step 2) and 24 (step 1) were noted.

No abnormal behaviour or clinical signs were detected during the experiment in the animals.

Skin reactions after the epicutaneous induction exposure were marked.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

No animal was regarded as sensitised by the test substance.

Executive summary:

Skin sensitisation: key study in guinea pigs, according to EC-directive 96/54, B.6., "Skin Sensitization" and the OECD-guideline 406, "Skin Sensitisation".

The "maximisation test" was performed to reveal a possible sensitising potential of Zirkonium-tetrakis(isobutyrato). The study was performed in two consecutive steps. In both steps a test substance group with 10 female guinea pigs and a negative control group with 5 female guinea pigs was used.

There were two induction exposures (intradermal and epicutaneous) and one challenge exposure. In both steps the test substance concentrations were derived from the results of a preliminary test: 0.5 % (w/v) in acetone for the intradermal induction 25 % (w/v) in acetone for the epicutaneous induction and 25 % (w/v) in acetone for the challenge exposure. 25% (w/v) in acetone was the highest technically feasible test substance concentration. Application of Freund's complete adjuvant was included in the intradermal exposure of both groups to enhance a possible sensitisation. For the epicutaneous exposures occlusive dressings were used.

Results showed that all animals survived till the end of the study. No relevant systemic toxic signs were observed. Intradermal injections of Freund's adjuvant caused severe local reactions in all animals, a known effect of the adjuvant. No other adverse effects were noted. The control sites of all animals of both groups were unaffected at each reading time. Neither animals of the test substance group in step 1 had positive skin reactions nor animals of the test substance group in step 2 had positive skin reactions at the test substance treated sites 24 hours and/or 48 hours after the end of the exposure. No adverse skin reactions were observed in the control animals. Therefore no animal of the test substance group was regarded as sensitised.