Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Toxicological information

Skin irritation / corrosion

Currently viewing:

Administrative data

Endpoint:
skin corrosion: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report date:
2017

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Reconstructed Human Epidermis (RHE) Test Method)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
2,5-di-tert-butylhydroquinone
EC Number:
201-841-8
EC Name:
2,5-di-tert-butylhydroquinone
Cas Number:
88-58-4
Molecular formula:
C14H22O2
IUPAC Name:
2,5-di-tert-butylhydroquinone
Specific details on test material used for the study:
The test substance is identified as di-tert-butyl hydroquinone. The purity is 99.6%. The physical state/appearance of material is white solid. The expiry date of material is 01 March 2019. The substance can be stored at room temperature in the dark conditions.

In vitro test system

Test system:
human skin model
Source species:
human
Cell type:
other: The target cells are epithelial, derived from human skin, and formed into a stratified, cornified epithelium.
Details on test system:
EpiDerm™ Reconstructed Human Epidermis Model Kit- 24-well plate
Control samples:
yes, concurrent negative control
yes, concurrent positive control
Amount/concentration applied:
25 mg of the test item with 99.6% purity
Duration of treatment / exposure:
Tissues were treated with the test item for exposure periods of 3 and 60 minutes.
Number of replicates:
Duplicate

Test system

Details on study design:
Main Test

Pre-Incubation
0.9 mL of this assay medium was pipetted into the appropriate wells of two pre-labeled 6-well plates for both the 3-Minute and 60-Minute exposure periods.
EpiDerm™ tissues were transferred into the 6-well plates containing the assay medium. The 6-well plates containing the EpiDerm™ samples were pre-incubated (37 °C, 5% CO2) for approximately 1 hour before dosing.

Application of Test Item and Rinsing

Before pre-incubation was complete, a 24-well plate was prepared for use as a “holding plate” for both the 3-Minute and 60-Minute exposure periods. This plate was used to maintain the viability of the tissue inserts between rinsing following chemical exposure and MTT loading. Another 24-well plate was prepared for the MTT loading. 300 μL of either pre-warmed assay medium (holding plate) or MTT medium (MTT loading plate) was dispensed into each well. The two plates were placed into the incubator until required.After pre-incubation of the EpiDerm™ tissues, the medium was aspirated and replaced with 0.9 mL of fresh assay medium. The 6-well plate for the 3-Minute exposure period was returned to the incubator, while the other was being dosed for the 60-Minute exposure.For the 60-Minute exposure period, 50 μL of sterile distilled water (negative control) was added to the first two tissues. 25 mg of the test item and 50 μL of 8.0 N Potassium Hydroxide (positive control) were also applied to the corresponding tissues in turn. 25 μL of sterile water was added for wetting of the test item to increase tissue surface contact. The plate was returned to the incubator (37 °C, 5% CO2) for the 60-Minute exposure period.When dosing for the 60-Minute exposure period was complete, the same procedure was repeated for the 3-Minute exposure period. Rinsing was achieved by filling and emptying each tissue under a constant soft stream of Dulbecco’s Phosphate Buffered Saline (DPBS) to gently remove any residual test item. Each tissue was placed into the prepared holding plate until all tissues were rinsed. They were then blotted and transferred to the 24-well plate prepared for MTT loading. The plate was incubated (37 °C, 5% CO2) for 3 hours. Once the 60-Minute exposure period was complete, the same rinsing and MTT loading procedure was repeated.
After the 3-Hour MTT incubation was complete, the inserts were blotted and transferred to labeled 24-well plates for MTT extraction. 2 mL of MTT extractant (isopropanol) was used to completely immerse each insert and the plate was covered with plate sealer to prevent Isopropanol evaporation. The plates stood overnight at room temperature, to allow extraction to proceed.

Absorbency at 570nm (OD570) of each well was measured using the Labtech LT-4500 microplate reader.

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
3 minute
Value:
89.2
Negative controls validity:
valid
Positive controls validity:
valid
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
60 minute
Value:
94.9
Negative controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The test item was considered to be non-corrosive to the skin.
Executive summary:

The corrosivity potential of di-tert-butyl hydroquinone was evaluated using the EpiDerm Human Skin Model after treatment periods of 3 and 60 minutes. Duplicate tissues samples were treated with the test item for exposure periods of 3 and 60 minutes. Negative and positive control groups were treated for each exposure period. At the end of the exposure period the test item was rinsed from each tissue before each tissue was taken for MTT-loading. After MTT loading each tissue was placed in isopropanol for MTT extraction. At the end of the formazan extraction period the optical density (OD) was measured at 570 nm. Percentage viability (MTT reduction in the test item treated tissues relative to negative control tissues) of test item for 3-minute exposure was 89.2% and after 60 minutes was 94.9%. Positive control showed the viability of 4.8 and 5.3% in 3 and 60 minutes exposure. The test item is not corrosive to skin and not classified for corrosivity in UN GHS or CLP regulations.