Bis(pentane-2,4-dionato-O,O')zinc

Endpoint summary

Description of key information

The concentration of test item expected to cause a 3 fold increase in 3HTdR incorporation (EC3 value) was calculated to be 11 %.

At a concentration of 25% w/w in dimethyl sulphoxide the test item caused a stimulation index of 3.94.

The test item was considered to be a sensitiser category 1B under the conditions of the test.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Reference 1

Endpoint:

skin sensitisation: in vivo (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 429 (Skin Sensitisation: Local Lymph Node Assay)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

CBA/Ca

Sex:

female

Details on test animals and environmental conditions:

Test animals were supplied by Harlan Laboratories UK Ltd., Oxon, UK.

Vehicle:

dimethyl sulphoxide

Concentration:

The animals were treated with 50 μI (25 μI per ear) of the test item as a solution in dimethyl sulphoxide at concentrations of 25%, 10% or 5% w/w, respectively.

No. of animals per dose:

Three groups, each of five animals, were used to conduct the test.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Positive control results:

a-Hexylcinnamaldehyde, tech., 85% gave a Stimulation Index of greater than 3 when tested at a concentration of 25% v/v in dimethyl sulphoxide.

Key result

Parameter:

EC3

Remarks:

EC3 value calculated based on 3 test results

Value:

11

Key result

Parameter:

SI

Value:

2.33

Test group / Remarks:

5% w/w in dimethyl sulphoxide

Key result

Parameter:

SI

Value:

2.94

Test group / Remarks:

10% w/w in dimethyl sulphoxide

Key result

Parameter:

SI

Value:

3.94

Test group / Remarks:

25% w/w in dimethyl sulphoxide

The Stimulation Index expressed as the mean radioactive incorporation for each treatment group divided by the mean radioactive incorporation of the vehicle control group are as follows:

Treatment group	Concentration	Stimulation index	Result
Test item	5% w/w in dimethyl sulphoxide	2.33	Negative
Test item	10% w/w in dimethyl sulphoxide	2.94	Negative
Test item	25% w/w in dimethyl sulphoxide	3.94	Positive
Positive control item	25% v/v dindimethyl sulphoxide	8.24	Positive

The concentration of test item expected to cause a 3 fold increase in 3HTdR incorporation (EC3 value) was calculated to be 11 %.

Interpretation of results:

Category 1 (skin sensitising) based on GHS criteria

Conclusions:

The concentration of test item expected to cause a 3 fold increase in 3HTdR incorporation (EC3 value) was calculated to be 11 %.
At a concentration of 25% w/w in dimethyl sulphoxide the test item caused a stimulation index of 3.94.
The test item was considered to be a sensitiser category 1B under the conditions of the test.

Executive summary:

According to Regulation (EC) No 1272/2008, chapter 3.4.2.2.3.1, a classification as a skin sensitiser category 1B has to be applied:

The EC3 value is above 2 %

Reference 2

Endpoint:

skin sensitisation: in vitro

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (sensitising)

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available