Octadecanoic acid, 1-(2-hydroxy-2-methylpropoxy)-2,2,6,6-tetramethyl-4-piperidinyl ester

Endpoint summary

Description of key information

The allergic potential of the test substance was evaluated in two independent studies with guinea pigs (according GLP and OECD guideline 406). In none of the studies the substance revealed any allergic reaction to skin and is therefore not consideredto be sensitizing. No experimental data is available regarding respiratory sensitisation. The particle size of the test substance is 1-2 mm and, therefore, not inhalable. Moreover, the test material did not reveal allergic potential in skin sensitisation tests, whereby respiratory sensititsation is not expected.

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

Study period:

2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1992

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

study was conducted before the implementation of the LLNA

Species:

guinea pig

Strain:

Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Hilltop Lab Animals, Inc., Scottdale, Pennsylvania
- Age at study initiation: nn
- Weight at study initiation: nn
- Housing: Cage cards displaying at least the study number, animal number and sex were affixed to each cage. The animals were housed individually in suspended stainless steel cages. All housing and care were based on the standards recommended by the Guide for the Care and Use of Laboratory Animals
- Diet (e.g. ad libitum): PMI Certified Guinea Pig Chow ad libitum
- Water (e.g. ad libitum): tap water ad libitum
- Acclimation period: 5d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18-23
- Humidity (%): 32-60
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12

IN-LIFE DATES: 2.3.-3.4.2000

Route:

intradermal

Vehicle:

polyethylene glycol

Concentration / amount:

Injections for induction were as indicated below:
a. Injection Pair A: 0.1 mL of FCA emulsion
b. Injection Pair B: 0.1 mL of 1.0% test material in PEG 400
c. Injection Pair C: 0.1 mL of 1.0% test material/FCA emulsion

Route:

intradermal and epicutaneous

Vehicle:

polyethylene glycol

Concentration / amount:

Injections for the challenge and rechallenge control animals were as indicated below:
a. Injection Pair A: 0.1 mL of FCA emulsion
b. Injection Pair B: 0.1 mL of PEG 400
c. Injection Pair C: 0.1 mL of 1.0% PEG 400/FCA emulsion

No. of animals per dose:

10

Details on study design:

Dermal Observations
The test sites at challenge were graded for dermal irritation at approximately 24 and 48 hours following chamber removal using the Dermal Grading System

Clinical Observations
Any unusual observations and mortality were recorded. The animals were observed for general health/mortality twice daily, once in the morning and once in the afternoon.

Body Weights
Individual body weights were obtained for all sensitization study animals on the day prior to intradermal induction (day -1) and for the test and challenge control animals on the day prior to challenge dosing. Final body weights were collected for all animals prior to euthanasia.

Scheduled Euthanasia
All sensitization study animals were euthanized by carbon dioxide inhalation following each animal's final scoring interval. Gross necropsy examinations were not required for these animals.

Challenge controls:

topical induction 0.8 ml PEG (solvent), challenge: 0.25g

Positive control substance(s):

yes

Remarks:

alpha-Hexylcinnamaldehyde

Positive control results:

Using «-Hexylcinnamaldehyde as a positive control, Springbom Laboratories, Inc., Spencerville, Ohio, has completed a study during the past six months which provided historical control data for contact sensitization to this agent utilizing the test system described herein (Maximization Design). Following intradermal induction at 5.0% w/v alpha-Hexylcinnamaldehyde in propylene glycol, topical induction at 5.0% w/v alpha-Hexylcinnamaldehyde in propylene glycol and challenge at levels of 0.5% and 1.0% w/v «-Hexylcinnamaldehyde in propylene glycol, a contact sensitization response was observed, thereby demonstrating the susceptibility of the test system to this sensitizing agent.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

100%

No. with + reactions:

0

Total no. in group:

20

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

100%

No. with + reactions:

0

Total no. in group:

10

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

100%

No. with + reactions:

0

Total no. in group:

20

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

100%

No. with + reactions:

0

Total no. in group:

10

Interpretation of results:

GHS criteria not met

Conclusions:

Based on the results of this study, the test substance is not considered to be a contact sensitizer in guinea pigs. The results of the alpha-Hexylcinnamaldehyde historical control study demonstrated that the test design utilized by Springbom Laboratories would detect potential contact sensitizers.

Executive summary:

The dermal sensitization potential of the test substance was evaluated in Harley-derived albino guinea pigs. Ten male and ten female guinea pigs received intradermal injections of 1.0 % w/v of the test substance in polyethylene glycol 400 (PEG 400) along with injections of FCA and the test substance in FCA. One week later, the test animals received a topical application of 100 % test substance. Challenge and rechallenge control animals received similar intradermal and topical treatments except PEG 400 was used in place of the test article. Following a two-week rest period, a challenge was performed whereby the twenty test and ten challenge control guinea pigs were topically treated with 100 % w/v test substance. Challenge responses in the test animals were compared with those of the challenge control animals. Following the challenge with 100 % test substance, dermal scores of 0 to +/- were noted in all test animals, while dermal scores of 0 were noted in all challenge control animals. Group mean dermal scores in the test animals were comparable to the challenge control animals. Using alpha-Hexylcinnamaldehyde as a positive control, the laboratory has completed a study during the past six months which provided historical control data for contact sensitization to this agent utilizing the test system described herein (Maximization Design). Following intradermal induction at 5.0 % w/v alpha-Hexylcinnamaldehyde in propylene glycol, topical induction at 5.0 % w/v alpha-Hexylcinnamaldehyde in propylene glycol and challenge at levels of 0.5 % and 1.0 % w/v alpha-Hexylcinnamaldehyde in propylene glycol, a contact sensitization response was observed, thereby demonstrating the susceptibility of the test system to this sensitizing agent. Based on the results of this study, the test substance is not considered to be a contact sensitizer in guinea pigs. The results of the alpha-Hexylcinnamaldehyde historical control study demonstrated that the test design utilized by Springborn Laboratories would detect potential contact sensitizers.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The dermal sensitization potential of the test substance (TS) was evaluated in two studies. In the first study, ten male and ten female Hartley-derived albino guinea pigs received intradermal injections of 1.0% w/v TS in polyethylene glycol 400 (PEG 400) along with injections of FCA and TS in FCA. One week later, the test animals received a topical application of 100% TS. Challenge and rechallenge control animals received similar intradermal and topical treatments except PEG 400 was used in place of the test article. Following a two-week rest period, a challenge was performed whereby the twenty test and ten challenge control guinea pigs were topically treated with 100% w/v TS. Challenge responses in the test animals were compared with those of the challenge control animals. Following challenge with 100% TS, dermal scores of 0 were noted in all test animals, while dermal scores of 0 were noted in all challenge control animals. Group mean dermal scores in the test animals were comparable to the challenge control animals. In a second irritation study, the test material was administered as 1% w/v mixtures in mineral oil and Freund's Complete Adjuvant (FCA) for the intradermal injection phase and as a 50% w/w mixture in petrolatum for both the topical induction and challenge applications in the definitive study. A definitive sensitization test according to the method of Magnusson and Kligman was then conducted. None of the animals in the test or irritation control groups exhibited a dermal reaction to the challenge application of the test or control materials.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Classification, Labeling, and Packaging Regulation (EC) No. 1272/2008

The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is not considered to be classified for skin sensitization under Regulation (EC) No. 1272/2008.