Registration Dossier

Administrative data

Endpoint:
skin corrosion: 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:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
liquid
Details on test material:
pH value: 12.2
Specific details on test material used for the study:
Batch identification: C520/094/2017

In vitro test system

Test system:
artificial membrane barrier model
Source species:
other: Corrositex® kit
Details on animal used as source of test system:
Corrositex® kit, InVitro International, Irvine CA, USA
Justification for test system used:
The Corrositex® assay is a standardized in vitro corrosion test. The Corrositex® assay kit is commercially available from InVitro International
Vehicle:
unchanged (no vehicle)
Details on test system:
The Corrositex® Biobarrier Membrane is a test system consisting of a reconstituted collagen matrix. The assay is based on the time that the test substance requires to penetrate through the Corrositex® Biobarrier Membrane and produce a change in the Chemical Detection System (CDS).

The Corrositex® assay is used to determine the corrosive potential of test substances. The assay is limited to testing materials which cause detectable pH changes in the CDS .
Amount/concentration applied:
undiluted

Test animals

Species:
other:

Test system

Vehicle:
unchanged (no vehicle)
Controls:
yes
Amount / concentration applied:
500 µL of the undiluted test substance were added onto the membrane disc
Duration of treatment / exposure:
one time
Observation period:
The time until a color change was observed was recorded manually and the breakthrough times of the four replicates were used to determine the corrosive potential of the test substance.

The first vial was observed for three minutes for any change in the CDS. If no color change was observed within three minutes, the remaining membranes were treated with the test substance. An electronic time clock was started with each application. The vials were continuously observed for the first ten minutes. Thereafter, the vials were observed for approximately ten minutes around the time points relevant for evaluation or until breakthrough of the test substance occurred
Details on study design:
The experimental design of this study consisted of
- a qualification screen with the CDS (to determine if a color change can be detected)
- a categorization screen (to categorize weak acids/bases and strong acids/bases
- a definitive Corrositex® assay

Corrositex® assay

Following the acceptance of the positive control, the Corrositex® assay was performed for the test substance. Four vials containing the CDS were used for the test substance.

In addition, one vial was used for the PC, the NC and the color control (blank) each.
A membrane disc coated with the biobarrier matrix was placed into one vial containing the CDS and approximately 500 µL test substance were added onto the membrane disc. The vial was observed for three minutes for any change in the CDS.

If no color change was observed within three minutes the membranes remaining were treated with the test substance. The vials were observed continuously for the first ten minutes. Thereafter, the vials were observed for approximately ten minutes around the time points relevant for evaluation or until breakthrough of the test substance. The elapsed time between test substance application and the first change in the indicator solution (i.e. barrier penetration) was recorded.

The positive control vial was prepared as described above and contained one pellet of sodium hydroxide on top of the membrane disc. This vial was continuously monitored until breakthrough.

The negative control vial was prepared as described above and contained 500 µL 10% citric acid. This vial was observed for 60 minutes and was evaluated as “non-corrosive” if no reaction had been observed.

Results and discussion

In vitro

Results
Irritation / corrosion parameter:
penetration time (in minutes)
Value:
51.07
Vehicle controls validity:
not examined
Negative controls validity:
valid
Positive controls validity:
valid
Other effects / acceptance of results:
PRETEST
Qualification screen: the test substance can react with the CDS and produce a visible color change.

Applicant's summary and conclusion

Interpretation of results:
Category 1B (corrosive) based on GHS criteria
Conclusions:
The mean breakthrough time determined in the in vitro membrane barrier test was 51 minutes and 7 seconds.
Executive summary:

Based on the results observed it was concluded that Reaction product of 2,4-Dinitrotoluene and 2,6-Dinitrotoluene and hydrogen, deaminated shows a corrosive potential in the Corrositex® - Skin Corrosion Test and should be assigned to UN GHS skin corrosivity subcategory 1B.