Acetic acid, esters with turpentine-oil myrcene fraction terpene alcs.

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

p-menth-1-en-8-yl acetate

EC Number:

201-265-7

EC Name:

p-menth-1-en-8-yl acetate

Cas Number:

80-26-2

Molecular formula:

C12H20O2

IUPAC Name:

1-methyl-1-(4-methylcyclohex-3-en-1-yl)ethyl acetate

Constituent 2

Reference substance name:

Myrcenyl acetate

EC Number:

214-262-0

EC Name:

Myrcenyl acetate

Cas Number:

1118-39-4

Molecular formula:

C12H20O2

IUPAC Name:

1,1-dimethyl-5-methylenehept-6-en-1-yl acetate

Constituent 3

Reference substance name:

(E)-2-(3,3-dimethylcyclohexylidene)ethyl acetate

EC Number:

308-183-1

EC Name:

(E)-2-(3,3-dimethylcyclohexylidene)ethyl acetate

Cas Number:

97890-04-5

Molecular formula:

C12H20O2

IUPAC Name:

(E)-2-(3,3-dimethylcyclohexylidene)ethyl acetate

Constituent 4

Reference substance name:

(Z)-2-(3,3-dimethylcyclohexylidene)ethyl acetate

EC Number:

308-184-7

EC Name:

(Z)-2-(3,3-dimethylcyclohexylidene)ethyl acetate

Cas Number:

97890-05-6

Molecular formula:

C12H20O2

IUPAC Name:

(Z)-2-(3,3-dimethylcyclohexylidene)ethyl acetate

Constituent 5

Reference substance name:

Geranyl acetate

EC Number:

203-341-5

EC Name:

Geranyl acetate

Cas Number:

105-87-3

Molecular formula:

C12H20O2

IUPAC Name:

(E)-3,7-dimethylocta-2,6-dien-1-yl acetate

Constituent 6

Reference substance name:

1-methyl-4-(1-methylethylidene)cyclohexyl acetate

EC Number:

233-564-3

EC Name:

1-methyl-4-(1-methylethylidene)cyclohexyl acetate

Cas Number:

10235-63-9

Molecular formula:

C12H20O2

IUPAC Name:

4-isopropylidene-1-methylcyclohexyl acetate

Constituent 7

Reference substance name:

4-(5-methyl-1-methylene-4-hexenyl)-1-(4-methylpent-3-enyl)cyclohexene

EC Number:

208-546-3

EC Name:

4-(5-methyl-1-methylene-4-hexenyl)-1-(4-methylpent-3-enyl)cyclohexene

Cas Number:

532-87-6

Molecular formula:

C20H32

IUPAC Name:

4-(5-methyl-1-methylenehex-4-en-1-yl)-1-(4-methylpent-3-en-1-yl)cyclohexene

Constituent 8

Reference substance name:

cis-1-methyl-4-(1-methylvinyl)cyclohexyl acetate

EC Number:

244-028-3

EC Name:

cis-1-methyl-4-(1-methylvinyl)cyclohexyl acetate

Cas Number:

20777-47-3

Molecular formula:

C12H20O2

IUPAC Name:

4-isopropenyl-1-methylcyclohexyl acetate

Constituent 9

Reference substance name:

p-menth-1-en-8-ol

EC Number:

202-680-6

EC Name:

p-menth-1-en-8-ol

Cas Number:

98-55-5

Molecular formula:

C10H16O

IUPAC Name:

2-(4-methylcyclohex-3-en-1-yl)propan-2-ol

Constituent 10

Reference substance name:

Neryl acetate

EC Number:

205-459-2

EC Name:

Neryl acetate

Cas Number:

141-12-8

Molecular formula:

C12H20O2

IUPAC Name:

(Z)-3,7-dimethylocta-2,6-dien-1-yl acetate

Constituent 11

Reference substance name:

1-(3,3-dimethylcyclohex-1-en-1-yl)ethyl acetate

Cas Number:

150461-96-4

Molecular formula:

C12H20O2

IUPAC Name:

1-(3,3-dimethylcyclohex-1-en-1-yl)ethyl acetate

Constituent 12

Reference substance name:

Tentative monoterpene diacetate

IUPAC Name:

Tentative monoterpene diacetate

Constituent 13

Reference substance name:

Tentative oxygenated monoterpene acetate

IUPAC Name:

Tentative oxygenated monoterpene acetate

Constituent 14

Reference substance name:

Tentative Diterpene hydrocarbon

IUPAC Name:

Tentative Diterpene hydrocarbon

Constituent 15

Reference substance name:

Unresolved/non-elucidated mixed terpene/diterpene/oxygenated terpene/terpene acetate derivatives

IUPAC Name:

Unresolved/non-elucidated mixed terpene/diterpene/oxygenated terpene/terpene acetate derivatives

Test material form:

liquid

Specific details on test material used for the study:

Identification: Neobergamate Forte
Appearance: Pale yellow liquid
Batch: SC00015234
Purity/Composition: See Certificate of Analysis
Test item storage: At room temperature protected from light
Stable under storage conditions until: 07 November 2016 (expiry date)

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Details on animal used as source of test system:

EPISKIN Small ModelTM (EPISKIN-SMTM, 0.38 cm2, Batch no.: 16-EKIN-005).
This model is a three-dimensional human epidermis model, which consists of adult human-derived epidermal keratinocytes which have been seeded on a dermal substitute consisting of a collagen type I matrix coated with type IV collagen. The keratinocytes were cultured for 13 days, which results in a highly differentiated and stratified epidermis model comprising the main basal, supra basal, spinous and granular layers and a functional stratum corneum.

Source
SkinEthic Laboratories, Lyon, France.

Justification for test system used:

In the interest of sound science and animal welfare, a sequential testing strategy is recommended to minimise the need of in vivo testing. One of the validated in vitro skin irritation tests is the EPISKIN test, which is recommended in international guidelines (e.g. OECD and EC).

Vehicle:

unchanged (no vehicle)

Details on test system:

Application/Treatment of the test item
In the first test the standard deviation of the replicates treated with the test item was above acceptance criteria (not reported), therefore a repeat test was performed. The test was performed on a total of 3 tissues per test item together with negative and positive controls. Twenty five μl of the undiluted test item was added into 12-well plates on top of the skin tissues. Three tissues were treated with 25 μl PBS (negative control) and 3 tissues with 25 μl 5% SDS (positive control) respectively. The positive control was re-spread after 7 minutes contact time. After the exposure period of 15 ± 0.5 minutes at room temperature, the tissues were washed with phosphate buffered saline to remove residual test item. After rinsing, the cell culture inserts were each dried carefully and moved to a new well on 2 ml pre-warmed maintenance medium until all tissues were dosed and rinsed. Subsequently the skin tissues were incubated for 42 hours at 37°C.

Cell viability measurement
After incubation, cell culture inserts were dried carefully to remove excess medium and were transferred into a 12-wells plate prefilled with 2 ml MTT-solution (0.3 mg/ml in PBS). The tissues were incubated for 3 h at 37°C. After incubation the tissues were placed on blotting paper to dry the tissues. Total biopsy was made by using a biopsy punch. Epidermis was separated from the collagen matrix and both parts were placed in prelabeled microtubes and extracted with 500 μl isopropanol (Merck, Darmstadt, Germany). Tubes were stored refrigerated and protected from light for approximately 70 hours. The amount of extracted formazan was determined spectrophotometrically at 570 nm in duplicate with the TECAN Infinite® M200 Pro Plate Reader.
Cell viability was calculated for each tissue as a percentage of the mean of the negative control tissues. Skin irritation potential of the test item was classified according to remaining cell viability following exposure of the test item.

Amount/concentration applied:

The liquid test item was applied undiluted (25 μl) directly on top of the tissue.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Value:

> 50

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

Acceptability of the assay
The in vitro skin irritation test is considered acceptable if it meets the following criteria:
a) The absolute mean OD570 (optical density at 570 nm) of the three tissues of the negative control should reasonably be within the laboratory historical control data range and the Standard Deviation value (SD) of the % viability should be ≤18.
b) The mean relative tissue viability of the positive control should be ≤50% relative to the negative control and the Standard Deviation value (SD) of the % viability should be ≤18.
c) The SD calculated from individual % tissue viabilities of the three identically treated replicates should be ≤18.

Data evaluation and statistical procedures
A test item is considered irritant in the skin irritation test if:
The relative mean tissue viability of three individual tissues after 15 minutes of exposure to the test item and 42 hours of post incubation is ≤ 50% of the mean viability of the negative controls.
A test item is considered non-irritant in the in vitro skin irritation test if:
The relative mean tissue viability of three individual tissues after 15 minutes of exposure to the test item and 42 hours of post incubation is > 50% of the mean viability of the negative controls.

Data interpretation of test items
Relative mean viability of 3 individual tissues after 15 minutes of exposure and 42 hours of post incubation - Prediction to be considered
≤ 50% of the mean viability of the negative controls - Category 1 or Category 2 (additional information on corrosion needed)
> 50% of the mean viability of the negative controls - No category

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

It is concluded that this test is valid and that Neobergamate Forte is non-irritant in the in vitro skin irritation test under the experimental conditions described in this report and should not be according to the Globally Harmonized System of Classification and Labeling of Chemicals (GHS) of the United Nations.