tert-pentylbenzene

Endpoint summary

Description of key information

- Skin Corrosion (OECD 431, GLP, Reliability.1): not corrosive

- Eye Irritation (BCOP, GLP, Reliability.1): non-irritant in the Bovine Corneal Opacity and Permeability test.

- Respiratory Irritation: no data available.

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

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

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 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

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%.

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

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

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

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.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 11 May to 06 June 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study.

Qualifier:

according to guideline

Guideline:

other: ICCVAM: Current status of in vitro test methods for identifying ocular corrosives and severe irritants: The Bovine Corneal Opacity and Permeability (BCOP ) Test Method, March 2006

Deviations:

not applicable

GLP compliance:

yes (incl. QA statement)

Species:

other: Bovine eyes

Details on test animals or tissues and environmental conditions:

TEST SYSTEM
- Test system: Bovine eyes from young cattle were obtained from the slaughterhouse
- Source: Vitelco, 's Hertogenbosch, The Netherlands

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 32 +/- 1°C

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 750 µl of the control or test substance was introduced onto the epithelium of the cornea.

Duration of treatment / exposure:

The Corneas were incubated for 10 +/- 1 minutes.

Number of animals or in vitro replicates:

Three corneas were selected at random for each treatment group.

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): After the incubation the control or test substance was removed and the epithelium was washed at least three times with cMEM (Eagle's Minimum Essential Medium).

SCORING SYSTEM: Opacity determinations were performed on the corneas using a opacitometer. The change in opacity for each individual cornea (including the negative control) was calculated by subtracting the initial opacity reading from the final post-treatment reading. Following the final opacity measurement, permeability of the cornea was evaluated. The mean opacity and mean permeability values were used for each treatment group to calculate an in vitro score. If this in-vitro score ranges between 0-3 the test substance is non-irritant. If the in-vitro score is >80 the test substance is very severe irritant.

Irritation parameter:

cornea opacity score

Run / experiment:

10 minutes (topical application)

Value:

ca. 1

Vehicle controls validity:

valid

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

See Table 1. The in vitro irritancy scores of the corneas treated with Tertiary-amylbenzene ranged from 0.2 to 1.7 with a mean of 1.0. Since all in vitr scores were less than 3.1 Tertiary-amylbenzene was considered non-irritant.
Based on the results obtained with the negative and positive control, it can be concluded that the test conditions were adequate and the test system functioned properly.

Table 1: Summary of opacity, permeability and in vitro scores

Treatment	Mean opacity	Mean permeability	Mean in vitro score
Negative control	0	-0.001	0.0
Positive control	87	6.170	179
Tertiary-amylbenzene	0	0.046	1.0

Interpretation of results:

GHS criteria not met

Conclusions:

Under the test conditions of this study, Tertiary-amylbenzene is non irritant in the Bovine Corneal Opacity and Permeability according to EU criteria.

Executive summary:

Screening for the eye irritancy potential of Tertiary-amylbenzene using the Bovine Corneal Opacity and Permeability test (BCOP test) was performed. The possible ocular irritancy of Tertiary-amylbenzene was tested through topical application for 10 minutes. The test substance was applied undiluted (750 µL) directly on top of the corneas.

The mean in vitro irritancy score obtained with the negative control was less than 3.1 indicating that the negative control did not induce irritancy on the corneas. The mean in vitro irritancy score of the positive control (10% w/v Benzalkonium chloride) was within the historical positive control data range. It was therefore concluded that the test conditions were adequate and that the test system functioned properly.

The in vitro irritancy scores of the corneas treated with Teritiary-amylbenzene ranged from 0.2 to 1.7 with a mean of 1.0. Since all in vitro irritancy scores were less than 3.1, Tertiary-amylbenzene was considered non-irritant.

Under the test conditions of this study, it is concluded that this test is valid and that Tertiary-amylbenzene is non-irritant in the Bovine Corneal Opacity and Permeability according to EU criteria.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Respiratory irritation

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

1- Skin corrosion/irritation:

One study was available and considered as the key study. 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)).

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.

2- Eye irritation:

One study was available and considered as the key study. Screening for the eye irritancy potential of Tertiary-amylbenzene using the Bovine Corneal Opacity and Permeability test (BCOP test) was performed. The possible ocular irritancy of Tertiary-amylbenzene was tested through topical application for 10 minutes. The in vitro irritancy scores of the corneas treated with Teritiary-amylbenzene ranged from 0.2 to 1.7 with a mean of 1.0. Since all in vitro irritancy scores were less than 3, Tertiary-amylbenzene was considered non-irritant.

Under the test conditions of this study, it is concluded that this test is valid and that Tertiary-amylbenzene is non-irritant in the Bovine Corneal Opacity and Permeability.

3- Respiratory irritation:

No data available.

Justification for classification or non-classification

1- Harmonised classification:

No harmonized classification is available according to the Regulation (EC) No 1272/2008.

2- Self-classification:

2.1- Skin Corrosion: based on the results of the key study, Tertiary-amylbenzene is not considered as corrosive to skin and not classified according to EU criteria.

2.2- Eye Irritation: based on the results of the key study, Tertiary-amylbenzene is not considered as irritating to eyes and not classified according to EU criteria.

2.3- Respiratory irritation:

No classification is possible due to lack of data.