4,4'-(4-methylpentane-2,2-diyl)bis((heptyloxy)benzene)

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17th December 2018 - 21st December 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)

Version / remarks:

Adopted 29 July 2016

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EC Guideline No. 440/2008. Part B: Methods for the Determination of Toxicity and other health effects, Guideline B.40 BIS: "In Vitro Skin Corrosion: Human Skin Model Test".

Version / remarks:

Official Journal of the European Union No. L142, 31 May 2008.

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1-(heptyloxy)-4-{2-[4-(heptyloxy)phenyl]-4-methylpentan-2-yl}benzene

EC Number:

830-582-9

Cas Number:

1951440-04-2

Molecular formula:

C32H50O2

IUPAC Name:

1-(heptyloxy)-4-{2-[4-(heptyloxy)phenyl]-4-methylpentan-2-yl}benzene

Test material form:

liquid: viscous

Specific details on test material used for the study:

Batch (Lot) Number: AS455433
Expiry date: 01 November 2020 (retest date)
Physical Description: Colourless to light yellow viscous liquid
Purity/Composition: 98.5%
Storage Conditions: At room temperature protected from light

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Justification for test system used:

Recommended test system in international guidelines (OECD and EC).

Vehicle:

unchanged (no vehicle)

Details on test system:

Test system:

EpiDerm Skin Model (EPI-200, Lot no.: 29674 Kit K and L, Appendix 4).
The model consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multilayered, highly differentiated model of the human epidermis.
It consists of organized basal, spinous and granular layers, and a multi-layered stratum corneum containing intercellular lamellar lipid layers arranged in patterns analogous to those found in vivo. The EpiDerm tissues (surface 0.6 cm²) were cultured on polycarbonate membranes of 10 mm cell culture inserts.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

Excessive amount of the undiluted substance
50 µL Milli-Q water (negative control)
50 µL 8N KOH (positive control)

Duration of treatment / exposure:

3 minutes and 1 hour

Duration of post-treatment incubation (if applicable):

3 hours (incubation with MTT).

Number of replicates:

Substance and controls: 2 for each time point

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minutes

Value:

95

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

no indication of irritation

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1 hour

Value:

102

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:

The absolute mean OD570 (optical density at 570 nm) of the negative control tissues was within the acceptance limits of OECD 431 (lower acceptance limit ≥0.8 and upper acceptance limit equal to or lower than 2.8) and the laboratory historical control data range. The mean relative tissue viability following the 1-hour exposure to the positive control was 6.6%.

Any other information on results incl. tables

Mean Absorption in the in vitro Skin Corrosion Test with the Substance.

	3 -minute application viability (%)				1 -hour application viability (%)
	A (OD570)	B (OD570)	Mean (OD570)	SD (+/-)	A (OD570)	B (OD570)	Mean (OD570)	SD (+/-)
Negative control	1.825	1.732	1.779	0.066	1.736	1.620	1.678	0.083
Substance	1.643	1.733	1.688	0.064	1.670	1.739	1.704	0.049
Positive control	0.102	0.124	0.113	0.015	0.108	0.112	0.110	0.003

SD = Standard deviation

Duplicate exposures are indicated by A and B.

In this table the values are corrected for background absorption (0.0424). Isopropanol was used to measure the background absorption.

Mean Tissue Viability in the in vitro Skin Corrosion Test with the Substance.

	3-minute application viability (% of control)	1-hour application viability (% of control)
Negative control	100	100
Substance	95	102
Positive control	6.3	6.6

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The substance is considered to be non-corrosive to skin based on a reliable in vitro skin corrosion study.

Executive summary:

In a reliable in vitro skin corrosion study, conducted according to the OECD Guideline 431, 'In Vitro Skin Corrosion: reconstructed human epidermis (RHE) test method', the undiluted substance (50 µL) was applied onto reconstructed human skin tissue (epidermal model, EpiDerm (EPI-200)) in duplicate for a period of 3 or 60 minutes.

Skin corrosion is expressed as the remaining cell viability after exposure to the substance. The relative mean tissue viability obtained after 3-minute and 1-hour treatments with the substance compared to the negative control tissues was 95% and 102%, respectively. Because the mean relative tissue viability for the substance was not below 50% after the 3-minute treatment and not below 15% after the 1-hour treatment the substance is considered to be not corrosive.

In conclusion, the substance is not corrosive in the in vitro skin corrosion test under the experimental conditions described in this study.