(2-hydroxy-1,1-dimethylethyl)ammonium toluene-4-sulphonate

Skin irritation / corrosion

Administrative data

Endpoint:

skin corrosion: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020-01-21 to 2020-03-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 435 (In Vitro Membrane Barrier Test Method for Skin Corrosion)

Version / remarks:

version 2015-07-28

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(2-hydroxy-1,1-dimethylethyl)ammonium toluene-4-sulphonate

EC Number:

269-537-8

EC Name:

(2-hydroxy-1,1-dimethylethyl)ammonium toluene-4-sulphonate

Cas Number:

68298-05-5

Molecular formula:

C7H8O3S.C4H11NO

IUPAC Name:

(2-hydroxy-1,1-dimethylethyl)ammonium toluene-4-sulphonate

Test material form:

solid

Details on test material:

(2-hydroxy-1,1-dimethylethyl)ammoniumtoluene-4-sulphonate from Evonik, Batch: NC19B11650

In vitro test system

Test system:

artificial membrane barrier model

Remarks:

In vitro Membrane Test Corrositex™- Assay

Justification for test system used:

The CORROSITEX™ Assay is a standardized, quantitative in vitro test for skin corrosivity and has been validated by the ECVAM for testing acids, bases and their derivatives [11]. The bio-barrier membrane is constructed to have physico-chemical properties similar to rat skin.

Details on test system:

CORROSITEX™ Assay Kit (Invitro International; Irvine, CA 92614, Lot No.: CT040119

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

100 mg of the test substance were addes to Tube A & B
500 mg of the test item were applied on top of the BIOBARRIER

Duration of treatment / exposure:

Table 1: Packing Group Designation
Category Time [min.] Time [min.] Time [min.] Time [min.]
1 0 – 3 > 3 - 60 > 60 - 240 > 240
2 0 - 3 > 3 - 30 > 30 - 60 > 60

Number of replicates:

4x BIOBARRIER discs

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

The corresponding BIOBARRIER has been treated with
- negative control: 500 µl of 10% Citric acid (in ddH2O)
- positive control: 500 µl of 85% Phosphoric Acid
- 500 g of solid test item

Duration of treatment / exposure:

based on the confirm experiment in the CORROSITX™, the chemical has been categorized in category 2. Therefore, the CDS solution was observed for 1 h. B

Observation period:

1 h

Details on study design:

BIOBARRIER Prepartion:
-The content of the BIOBARRIER diluent was added to the vial of BIOBARRIER matrix powder.
-The vial was heated to 68°C (± 1°C) in a water bath under smooth agitation.
-After complete dissolution the solution was allowed to sit for 5 min.
-200 µL of the BIOBARRIER were pipetted into each membrane disc.
-The BIOBARRIERS were set on the tray and kept in the cold (2 - 8°C) for at least 2 h before the test was conducted

Categorization Test:
- 100 mg of the test substance were added to the tubes A and B.
- After shaking a colour change was observed in either of the tubes and colour was matched to the corresponding colour charts on the CORROSITEX™ Testing Protocol Poster.
- If no colour change had been observed in either tube, CONFIRM reagent was added to Tube B. After shaking, the resulting colour was matched to the colour chart on the CORROSITEX™ Testing Protocol Poster.
If the test item has a strong inherent colour or shows other characteristics impairing a clear categorization according to the colour chart, the pH value can be measured in tubes A and B and is used to confirm/determine the category of the test item, according to the Corrositex® Reference Manual .
 
Classification Test:
- The CDS vials were warmed to room temperature
- Vials 1 - 4: sample replicate testing
- Vial labelled (+): positive control sample,
-Vial labelled (-) :negative control.
- Vial labelled C: CDS colour control.
- 1x BIOBARRIER disc was added on top of the first vial
- 500 mg of the test item were applied evenly on the top of the BIOBARRIER disc and starting time was recorded, this was repeated for the remaining vials, staggering each start time by e.g. 10 seconds.
The start time difference for each vial was subtracted from the final time to determine the net response time.
As soon as a reaction had been observed, the time was recorded.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

penetration time (in minutes)

Run / experiment:

Corrositex™

Value:

> 60

Negative controls validity:

valid

Remarks:

n.a. for 10% Citrix Acid

Positive controls validity:

valid

Remarks:

26.08 min for 85% Phosphoric Acid

Any other information on results incl. tables

Table2:  Results of the Test Item Propan-1-ol, 2-amino-2-methyl-, 4-methylbenzenesulphonate

	CORROSITEX™ Time [min]	Colour Change
Replicate 1	n.a.	no
Replicate 2	n.a.	no
Replicate 3	n.a.	no
Replicate 4	n.a.	no
Mean ± SD	n.a.
Positive control	26.08	yes
Negative control	n.a.	no

During the observation period of 1 h the CDS was not activated.

Applicant's summary and conclusion

Conclusions:

In conclusion, it can be stated that in this study and under the experimental conditions reported, the test item is not corrosive to skin.

Executive summary:

The potential of the test substance to induce skin corrosion was analysed by using the “In VitroMembrane Barrier Test (CORROSITEX™ Assay)”, comprising a Chemical Detection System covered by a bio-barrier membrane.

The test substance Propan-1-ol, 2-amino-2-methyl-, 4-methylbenzenesulphonate proved its ability to activate the CDS and was subsequently subjected to the timescale category test. The test substance was applied undiluted on top the bio-barrier membraneand the timerequired to activate the CDSwas measured in four replicates. The mean time was compared to the given thresholds (see Table 1).

The test substance was compatible with the CORROSITEX™ Assay, as assessed in the qualification step. The categorization step and the classification step could be performed.

A direct colour change was not observed. CONFIRM reagent was added to tube B and the category was read from the CORROSITEX™ colour chart. The chemical has been categorized to category 2.

In this study under the given conditions the test substance showed no corrosive effects as the mean time, required to activate the CDS, was > 60 min. (category 2). 

The controls confirmed the validity of the study. The positive control activated the CDS between 3 - 60 min. (26.08 min.), the negative control did not activate the CDS before 60 min.

 

This in vitro study was performed to assess the corrosive potential of test item by means of the in vitro Membrane Barrier Test for

Skin Corrosion (OECD TG 435) using the Corrositex™ test kit.