Tetrazinc trioxide phosphite

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04 September 2018 - 25 September 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Version / remarks:

22 July 2010

Deviations:

yes

Remarks:

Due to the receipt of a replacement sample, the batch number and expiry date differ to those stated in the Study Plan.

GLP compliance:

yes

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Tetrazinc trioxide phosphite

EC Number:

264-938-4

EC Name:

Tetrazinc trioxide phosphite

Cas Number:

64539-51-1

Molecular formula:

HO6PZn4

IUPAC Name:

Tetrazinc trioxide phosphite

Specific details on test material used for the study:

Batch: 1013T08961
Purity: 100%
Physical state / Appearance: White powder
Expiry Date: 29 March 2019
Storage Conditions: room temperature in the dark

In vivo test system

Test animals

Species:

mouse

Strain:

CBA/Ca

Remarks:

CBA/Ca (CBA/CaOlaHsd)

Sex:

female

Details on test animals and environmental conditions:

The animals were nulliparous and non-pregnant. Acclimatization period of at least 5 days. At the start of the study the animals were in the weight range of 15 to 23 g, and were 8 to 12 weeks old. The animals were housed in suspended solid floor polypropylene cages. Food and water was administered ad libitum. The temperature and relative humidity were set to achieve limits of 19 to 25 °C and 30 to 70%, respectively. The rate of air exchange was at least fifteen changes per hour and the lighting was controlled by a time switch to give 12 hours continuous light and 12 hours darkness.

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

25%, 10% or 5% w/w.

No. of animals per dose:

Four mice/concentration.

Positive control substance(s):

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

Results and discussion

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

0.96

Test group / Remarks:

5%

Results 2

Key result

Parameter:

SI

Value:

0.88

Test group / Remarks:

10%

Results 3

Key result

Parameter:

SI

Value:

1.49

Test group / Remarks:

25%

Any other information on results incl. tables

Preliminary test results:

The animal treated at a dose level of 50% showed no signs of systemic toxicity or visual local skin irritation but showed an increase in ear thickness of greater than 25% which was considered indicative of excessive irritation.

No signs of systemic toxicity, visual local skin irritation or irritation indicated by an equal to or greater than 25% increase in mean ear thickness were noted in the animal treated at a dose level of 25%.

Based on this information the dose levels selected for the main test were 25%, 10% and 5% w/w in acetone/olive oil 4:1.

Main test:

There were no deaths. No signs of systemic toxicity were noted in the test or control animals during the test.

Body weight change of the test animals between Day 1 and Day 6 was comparable to that observed in the corresponding control group animals over the same period.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The substance is not a skin sensitiser under the conditions of the study.

Executive summary:

A study was undertaken to evaluate the potential of the substance to induce delayed contact hypersensitivity using the murine Local Lymph Node Assay. Evaluation of irritation was also conducted in parallel by measurement of ear thickness. Following a preliminary screening test in which no clinical signs of toxicity were noted at a concentration of 25% w/w, this concentration was selected as the highest dose investigated in the main test of the Local Lymph Node Assay. Three groups, each of four animals, were treated with 50 μL (25 μL per ear) of the substance as a solution in acetone/olive oil 4:1 at concentrations of 25%, 10% or 5% w/w. A further group of four animals was treated with acetone/olive oil 4:1 alone. The Stimulation Index expressed as the mean radioactive incorporation for each treatment group divided by the mean radioactive incorporation of the vehicle control group indicates that the substance is not a skin sensitiser.