2,4,8,10-Tetraoxaspiro[5.5]undecane-3,9-diethanol, .beta.3,.beta.3,.beta.9,.beta.9-tetramethyl-

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2006-06-07 to 2006-06-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test was performed according to guideline.

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Species:

mouse

Strain:

other: CBA/Ca

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Charles River UK Ltd, Margate, Kent, UK.
- Age at study initiation: Eight to twelve weeks old.
- Weight at study initiation: At the start of the study the animals were in the weight range of 12 to 23 g.
- Housing: Individually in suspended solid-floor polypropylene cages furnished with softwood wood flakes.
- Diet (e.g. ad libitum): Free access to food (certified Rat and Mouse Diet (Code 5LF2, BCM IPS Ltd, London, UK) was allowed throughout the study.
- Water (e.g. ad libitum): Free access to mains tap water was allowed throughout the study.
- Acclimation period: At least five days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25 °C
- Humidity (%): 30 - 70 %
- Air changes (per hr): Approximately 15 changes per hour.
- Photoperiod (hrs dark / hrs light): Twelve hours continuous light and twelve hours darkness.

Vehicle:

propylene glycol

Concentration:

50 µL (25 µL each ear) of 10, 25, and 50 % ww

No. of animals per dose:

4 animals per dose.

Details on study design:

RANGE FINDING TESTS:
As no toxicological information was available regarding the systemic toxicity/irritancy potential of the test material, a preliminary screening test was performed using one mouse. The mouse was treated by daily application of 25 µL of the test material at a concentration of 50 % w/w in propylene glycol, to the dorsal surface of each ear for three consecutive days (Days 1, 2, 3). The mouse was observed twice daily on Days 1, 2 and 3 and once daily on Days 4, 5 and 6. Any signs of toxicity or excessive local irritation noted during this period were recorded. The bodyweight of the mouse was recorded on Day 1 (prior to dosing) and on Day 6.
- Compound solubility: The test material was freshly prepared in propylene glycol. This vehicle was chosen as it produced the highest concentration that was suitable for dosing.
- Irritation:
- Lymph node proliferation response:

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method:
- Criteria used to consider a positive response: The proliferation response of lymph node cells was expressed as the number of radioactive disintegrations per minute per lymph node (dpm/node) and as the ratio of 3 HTdR incorporation into lymph node cells of test nodes relative to that recorded for the control nodes (Stimulation Index). The test material is considered a sensitiser if at least one concentration of the test material results in a threefold or greater increase in 3HTdr incorporation compared to control values. Any test material failing to produce a threefold or greater increase in 3HTdR incorporation will be classified as a non-sensitiser.

TREATMENT PREPARATION AND ADMINISTRATION:
The test material was freshly prepared in propylene glycol. This vehicle was chosen as it produced the highest concentration that was suitable for dosing.
Groups of four mice were treated with the test material at concentration of 10 %, 25 % or 50 % in propylene glycol. The preliminary screening test suggested that the test material would not produce systemic toxicity or excessive local irritation at the highest suitable concentration. The mice were treated by daily application of 25 µL of the appropriate concentration of the test material to the dorsal surface of each ear for three consecutive days (Days 1, 2 and 3). The test material formulation was administered using an automatic micropipette and spread over the dorsal surface of the ear using the tip of the pipette. A further group of four mice received the vehicle alone in the same manner.
Five days following the first topical application of the test material (Day 6) all mice were injected via the tail vein with 250 µL of phosphate buffered saline containing 3H-methyl thymidine (3HTdR: 80 µCi/mL, specific activity 2.0 ci/mmol) giving a total of 20 µCi to each mouse.

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: For the vehicle, the Dpm was 5049.24, with a Dpm/Node of 631.16. At 10 % w/w, the Dpm was 5427.71, with a Dpm/Node of 678.46. At 25 % w/w, the Dpm was 5763.99, with a Dpm/Node of 720.50. At 50 % w/w, the Dpm was 3751.66, with a Dpm/Node of 468.96.

Parameter:

SI

Value:

1.07

Test group / Remarks:

10 % (w/w) in propylene glycol

Parameter:

SI

Value:

1.14

Test group / Remarks:

25 % (w/w) in propylene glycol

Parameter:

SI

Value:

0.74

Test group / Remarks:

50 % (w/w) in propylene glycol

DPM, DPM/Node and Stimulation Index (SI):

concentration (%ww)	Dpm	Dpm/Node	Simulation Index (SI)	Result
vehicle	5049.24	631.16	N/A	N/A
10	5427.71	678.46	1.07	negative
25	5763.99	720.50	1.14	negative
50	3751.66	468.96	0.74	negative

Preliminary screening test.

No signs of systemic toxicity were noted. Based on this information the dose levels selected for the main test were 10 %, 25 % and 50 % w/w in propylene glycol.

 

Clinical observations and mortality.

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

 

Bodyweight.

Bodyweight changes of the test animals between Day 1 and Day 6 were comparable to those observed in the corresponding control group animals over the same period.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: expert judgment

Conclusions:

The test material was considered to be a non-sensitiser under the conditions of the test

Executive summary:

Using a method according to OECD Guideline for Testing of Chemicals No. 429 “Skin Sensitisation: Local Lymph Node Assay, and Method B42 Skin Sensitisation(Local Lymph Node Assay) of Commission Directive 2004/73/EC four “vehicle” mice and twelve “dosed” mice had been tested. No death occurred and body mass change was comparable between the vehicle group and the test group. DPM and Simulation Index (SI) determination showed negative results, and the test material was considered to be a non-sensitiser for mice under the test conditions.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A study was performed to assess the skin sensitisation potential of the test material in mice following topical application to the dorsal surface of the ear in a local lymph node assay performed according to EU Method B.42 and OECD Guideline 429.

 

There were no deaths and no signs of systemic toxicity in the test or control animals. There were no statistically significant changes in body weight. DPM and Simulation Index determination showed negative results, and the test material was considered to be a non-sensitiser for mice under the test conditions.

Migrated from Short description of key information:
The test substance was assessed for the potential to cause skin irritation according to EU Method B.42 and OECD Guideline 429. The test material was considered to be a non-sensitiser under the conditions of the test.

Justification for selection of skin sensitisation endpoint:
The study was performed to GLP according to EU Method B.42 and OECD Guideline 429 in an appropriate test species.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

A skin sensitiser is a substance that will lead to an allergic response following skin contact. Positive data from experimental studies on animals may be indicative of the potential of a substance to cause sensitisation. In the Local Lymph Node Assay, the result is considered positive when the Simulation Index is≥3, although, the strength of the dose-response, statistical significance and consistency of the solvent/vehicle and test substance responses may also be used when determining a positive result. 

In this study, a stimulation index of < 3 was recorded for the three concentrations of test material tested, thereby indicating that the substance is negative for skin sensitisation. The test substance should therefore not be classified as a skin irritant.