tert-pentylbenzene

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 to 15 June 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Version / remarks:

OECD Guideline 4.1 (In Vitro Skin Corrosion: Human Skin Model Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

tert-pentylbenzene

EC Number:

218-076-0

EC Name:

tert-pentylbenzene

Cas Number:

2049-95-8

Molecular formula:

C11H16

IUPAC Name:

(2-methylbutan-2-yl)benzene

Details on test material:

- Analytical purity: 97.4%
- Impurities: Cumene: 0.7%, Heptylbenzene (C13H18): 0.6%, Nonylbenzene (C15H22): 0.6%
- Lot/batch No.: Tank BV1112 du 18 avril 2007.

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Cell source:

other: MatTek Corporation, Ashland MA, U.S.A.

Vehicle:

unchanged (no vehicle)

Details on test system:

TEST SYSTEM
- Test system: The EpiDerm Skin Model consists of human-derived epidermal keratinocytes which have been cultured to form a multilayered, highly differential model of the human skin epidermis.
- Source: MatTek Corporation, Ashland MA, USA

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 36 +/- 1°C
- Humidity (%): 80 - 100% containing 5 +/- 0.5% CO2SKIN DISC PREPARATION
- Quality control for skin discs: Electrical resistance obtained with two of the isolated skin discs was [complete, e.g. 10 kΩ]

PREDICTION MODEL / DECISION CRITERIA (choose relevant statement)
- The test substance is considered to be corrosive to skin if [complete, e.g. if the mean TER value is less than or equal to 5 kΩ and the skin disk is obviously damaged, or if the mean TER value is less than or equal to 5 kΩ, and the skin disc is showing no obvious damage, but the mean disc dye content is greater than or equal to the mean disc dye content of the 10M HCl positive control obtained concurrently.]
- The test substance is considered to be non-corrosive to skin if [complete, e.g. if the mean TER value obtained for the test substance is greater than 5 kΩ, or if the mean TER value is less than or equal to 5 kΩ, and the skin disc is showing no obvious damage, and the mean disc dye content is well below the mean disc dye content of the 10M HCl positive control obtained concurrently.]

Control samples:

yes, concurrent MTT non-specific colour control

Amount/concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 µl of the undiluted test substances was added on top of the skin tissues into a 6-well plate.

Duration of treatment / exposure:

3 minutes or 1 hour.

Duration of post-treatment incubation (if applicable):

3 hours

Number of replicates:

3

Test system

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The tissues were washed with phosphate buffered saline to remove residual test substance.
- Time after start of exposure: 3 minutes and one hour exposure.

SCORING SYSTEM: Skin corrosion is expressed as the remaining cell viability following exposure of the test substance with either of the two exposuretimes. Cell viability was calculated for each tissue as percentage of the mean of the negative control tissues.
The test substance is corrosive if:
a) The relative mean tissue viability obtained after 3 min. treatment compared to the negative control tissues is decreased below 50%
b) In addition, a test substance considered non-corrosive after 3 min. is considered corrosive if the mean relative tissue viability after 1 hr treatment with the test substance is decreased below 15%.

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

After 3 minutes of exposure

Value:

91

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

After 1 hour of exposure

Value:

100

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Table 1: Mean tissue viability in the in vitro skin corrosion test

	3 min application viability (percentage of control)	1 hr application viability (percentage of control)
Negative control	100	100
Tertiary-amylbenzene	91	100
Positive control	15	13

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the test conditions of this study, Tertiary-amylbenzene is considered as not corrosive according to EU criteria.

Executive summary:

In vitro skin corrosion test with Teriatiary-amylbenzene was performed according to OECD 431 and in compliance with GLP. The possible corrosive potential of Tertiary-amylbenzene was tested through topical application for 3 minutes and 1 hour, using a human skin model (EpiDerm (EPI-200)). Tertiary-amylbenzene was applied undiluted (50µL) directly on top of the skin tissue.

The positive control had mean relative tissue viability after 3 minutes exposure of 15%. The absolute mean OD540 (optical density at 540 nm) of the negative control was within the laboratory historical control data range. The maximum inter tissue variability in viability between two tissues treated identically was less than 23% and the maximum difference in percentage between the mean viability of two tissues and one of the two tissues was less than 13% indicating that the test system functioned properly.

Skin corrosion is expressed as the remaining cell viability after exposure to the test substance. The relative mean tissue viability obtained after 3 minutes and 1 hour treatment with Tertiary-amylbenzene compared to the negative control tissues was 91% and 100% respectively.

Since the mean relative tissue viability for Tertiary-amylbenzene was not below 50% after 3 minutes treatment and not below 15% after 1 hour treatment, Tertiary-amylbenzene is considered to be not corrosive.

Under the test conditions of this study, it is concluded that this test is valid and that Tertiary-amylbenzene is not corrosive in the in vitro skin corrosion test.