(2S)-1-isopropoxy-1-oxopropan-2-yl pivalate

Endpoint summary

Description of key information

Not sensitising (OECD 406, GLP, K, rel. 1)

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Remarks:

Guinea Pig Maximisation Test

Type of information:

experimental study

Adequacy of study:

key study

Study period:

02 March to 10 April 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP study conducted in compliance with OECD Guideline No. 406 without any deviation.

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected on 03-04 June 2013 / signed on 13 September 2013

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

A scientific justification for completion of GPMT to fulfil the REACH chemical substance registration is attached to this ESR ("Attached Justification")

Specific details on test material used for the study:

- Purity test date: 29 January 2015
- Storage Conditions: 6 °C

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan, Kreuzelweg 53, 5961 NM Horst, The Netherlands.
- Age at study initiation: 3 or 4 weeks
- Housing: Animals were housed individually or in groups of 2 in polycarbonate containers.
- Diet: Food (SAFE, 106), ad libitum
- Water: Drinking water (tap water from public distribution system), ad libitum
- Acclimation period: 5 days
- Indication of any skin lesions: None

ENVIRONMENTAL CONDITIONS
- Temperature: 19–25 °C
- Humidity: 30-70 %
- Air changes: 10 changes per hour
- Photoperiod: 12 h dark / 12 h light

IN-LIFE DATES: 02 March to 10 April 2015

Route:

intradermal

Vehicle:

olive oil

Concentration / amount:

20 % w/w

Day(s)/duration:

Day 0

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

100 % w/w

Day(s)/duration:

Day 8 / 48 hours

Adequacy of induction:

non-irritant substance, but skin pre-treated with 10% SDS

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

unchanged (no vehicle)

Concentration / amount:

100% (undiluted)

Day(s)/duration:

Day 22 / 24 hours

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

10 and 5 animals for treatment and control groups, respectively

Details on study design:

PRELIMINARY STUDIES:
Determination by intradermal injection of the Maximal Non Necrotizing Concentration (MNNC):
Two animals received a volume of 0.1 mL of the test item, on both sides of the spine, at 4 concentrations: 100% and diluted at 50, 20 and 10% in olive oil in order to determine the MNNC. A macroscopic evaluation of the cutaneous reactions was conducted 24 h after the injections. No necrosis has been observed at the concentration of 20%. Therefore, 20% was selected for first induction in the main study.

Determination by topical application of the Pre-Maximal Non Irritant Concentration (Pre-MNIC):
Test item was applied on the dorso-lumbar zone of two guinea pigs shorn beforehand, with occlusive dressing for 24 h, at 4 different concentrations: 100% and diluted at 50, 20 and 10% in liquid paraffin. A macroscopic evaluation of the cutaneous reactions was conducted 24 h after removal of the dressing. No cutaneous reaction was noted at any of the concentration. In view of these results, the concentration selected was 100% for the 2nd induction and the MNIC determination began at the concentration of 100%.

Determination by topical application of the Maximal Non Irritant Concentration (MNIC):
Three guinea pigs were treated according to the same treatment as animals from GROUP 1 (negative control) for the induction phase (i.e. olive oil and liquid paraffin). During the challenge phase, the animals were treated with the test item placed onto the selected treatment sites and covered with an occlusive dressing for a period of 24 hours at 4 different concentrations: 100% and diluted at 50, 20 and 10% in liquid paraffin. A macroscopic evaluation of the cutaneous reactions was conducted 24 and 48 h after removal of the occlusive dressing. No cutaneous reaction was noted at any of the concentration. In view of this result, the concentrations selected were 100% (MNIC) for the challenge phase.

MAIN STUDY
A. INDUCTION EXPOSURE: INTRADERMAL
- No. of exposures: One
- Test groups: After shearing the scapular zone, three (3) pairs of intradermal injections (ID) of 0.1 mL were performed on the scapular zone in such a way as an injection on each pair is placed to either side of the spine as follows:
2 ID: Freund's Complete Adjuvant diluted at 50 % in olive oil
2 ID: test item at 20% in olive oil
2 ID: a test mixture in equal volumes v/v : Freund's Complete Adjuvant at 50% and the test item at 40% in olive oil
- Control group:
2 ID: Freund's Complete Adjuvant diluted at 50 % in olive oil
2 ID: olive oil
2 ID: a mixture with equal volumes v/v : - Freund's Complete Adjuvant at 50% and olive oil
- Site: Each side of the mid-line on scapular zone
- Exposure period: Day 0-6
- Duration: 6 days

Day 7: The scapular zone of all the animals in each group, shorn beforehand, was brushed with a solution of sodium lauryl sulfate at 10% in thick vaseline, in order to create a local irritation.

B. INDUCTION EXPOSURE: TOPICAL APPLICATION
- No. of exposures: One
- Exposure period: 48 h
Day 8: A topical application under occlusive dressing (25 mm x 25 mm gauze patches hydrophilic Codex of 8-layer Gazin® from Lohmann & Rauscher held in contact with the skin by means of 50 mm wide hypoallergenic micropore adhesive tape from 3M and Blenderm from 3M) for 48 h was performed on the injection sites of each animal.
- Test groups: 0.5 mL of the test item at 100%
- Control group: 0.5 mL of liquid paraffin
- Site: Same intradermally injected area of scapular zone
- Frequency of applications: Single application

Day 10: Occlusive dressing removal

C. Rest phase
- The animals of both groups were left for 10 days.

D. CHALLENGE EXPOSURE
- No. of exposures: One
- Day(s) of challenge: Day 22
- Exposure period: 24 h
- Day 23: Occlusive dressing removal
- The experimental procedure of this phase was identical for both negative control and treated groups submitted to this experimentation: on the previously shorn dorso-lumbar zone, an application under occlusive dressing, was performed during 24 h: - 1 sample cup (allergEAZE® clear patch test chamber - SmartPractice®) containing the test item at 100% (undiluted) (MNIC) and 1 sample cup (allergEAZE® clear patch test chamber SmartPractice®) containing liquid paraffin.
- Evaluation (h after removal of challenge patch): 24 and 48 h

Challenge controls:

None

Positive control substance(s):

yes

Remarks:

α-hexylcinnamaldehyde

Positive control results:

α-Hexylcinnamaldehyde induced skin sensitisation indicating the validity of the study (Study No.: SMK-2014-001; SMK-2014-002; SMK-2015-001).

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

100%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no cutaneous reaction was observed

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

liquid paraffin

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no cutaneous reaction was observed

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

100%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

no cutaneous reaction was observed

Remarks on result:

no indication of skin sensitisation

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

liquid paraffin

No. with + reactions:

0

Total no. in group:

5

Clinical observations:

no cutaneous reaction was observed

Remarks on result:

no indication of skin sensitisation

Key result

Group:

positive control

Remarks on result:

positive indication of skin sensitisation

Remarks:

α-Hexylcinnamaldehyde induced skin sensitisation indicating the validity of the study (Study No.: SMK-2014-001; SMK-2014-002; SMK-2015-001).

Main study

Induction phase: No cutaneous reaction was recorded in the treated and control groups during the induction phase.

Challenge phase: In the treated and control groups, no cutaneous reaction attributable to allergy was recorded in animals after the challenge phase. In both groups, no cutaneous intolerance reaction was recorded on the treated area with liquid paraffin at 24 and 48 h.

 

Mortality: No mortality was observed during the test.

 

Body weight: No abnormality was recorded in the body weight gain of both groups.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the test conditions, test item, ST 11 C 13 is not classified as sensitiser according to the Regulation (EC) No. 1272/2008 (CLP) and to the GHS.

Executive summary:

In a Magnusson & Kligman maximisation study (GPMT) performed according to OECD Guideline 406 and in compliance with GLP, female Dunkin-Hartley guinea pigs were treated as follows:

 

After induction (intradermal injection at 20% and topical application at 100%) of 10 Guinea Pigs of treated group with the test item ST 11 C 13 and a 10-day rest phase, the challenge phase, under occlusive dressing for 24 h, consisted to a single topical application of the test item at 100% and liquid paraffin as control. Control group of 5 females treated in similar manner. The test concentrations for the main study were determined from a preliminary study.

 

In the treated group (treatment dose of 100%), no cutaneous reaction attributable to allergy was recorded in animals 24 and 48 h after the challenge phase. In the control group (associated with the treatment dose of 100%), no cutaneous intolerance reaction was recorded at 24 and 48 h. In both groups, no cutaneous intolerance reaction was recorded on the treated area with liquid paraffin, at 24 and 48 h. No mortality was observed during the test. No abnormality was recorded in the body weight gain of both groups.

 

The sensitivity of the guinea-pig was checked with known sensitiser i.e., α-Hexylcinnamaldehyde indicating the validity of the study. 

 

Under the test conditions, test item ST 11 C 13 is not classified as sensitiser according to the Regulation (EC) No. 1272/2008 (CLP) and to the GHS.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

A key study was identified (Phycher, 2015). In this dermal sensitisation study performed according to the OECD guideline No. 406 and in compliance with GLP, the test material was tested in ten female Guinea Pigs using the Magnusson and Kligman method (10 treated animals + 5 controls). The preliminary study determined the concentration to be used for the induction and challenge phases of the main study. The test material diluted in olive oil at 20% (w/w) was administered by injection for intradermal induction. On Day 7, the animals received a topical application of sodium lauryl sulfate in vaseline (10% w/w), in order to induce local irritation. On Day 8, topical induction was performed with the test material as supplied. For the challenge, on Day 22, the test material was tested undiluted.

90% animals gave positive response to challenge concentrations of the last historical positive control α-Hexylcinnamaldehyde at a concentration of 12.5% at 24h and 48h. 50% and 70% positive response were noted at 24h and 48h respectively at a concentration of 6.25%. The test system was therefore considered to be valid.

In both groups, no clinical signs and no deaths were noted during the study. The body weight gain of the treated animals was similar to that of the control animals. After the challenge application, no cutaneous reaction was noted. The overall sensitisation rate was 0%.

Under the test conditions, the test material is not a skin sensitizer.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Harmonized classification:

The substance has no harmonized classification according to the Regulation (EC) No. 1272/2008.

 

Self classification:

Based on the available data no additional self-classification is proposed according to the Regulation (EC) No. 1272/2008 (CLP) and to the GHS.

No data was available for respiratory sensitisation. However, this substance is not a skin sensitizer, therefore according to Figure R.7.3 -2 of the Chapter R.7 (V 4.1 - October 2015) the chemical is not considered as a respiratory sensitizer.