2H-Tetrazol-5-amine, potassium salt (1:1)

Skin irritation / corrosion

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:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

potassium 5-amino-1H-1,2,3,4-tetrazol-1-ide

Cas Number:

136369-04-5

Molecular formula:

CH2KN5

IUPAC Name:

potassium 5-amino-1H-1,2,3,4-tetrazol-1-ide

Test material form:

solid: particulate/powder

Details on test material:

Batch no.: 08KI030

In vitro test system

Test system:

human skin model

Source species:

human

Cell type:

other: epidermal keratinocytes which have been cultured to form a multi-layered, highly differentiated model of the human epidermis.

Details on animal used as source of test system:

Epi-200 tissues and MTT-100 assays diluent were procured from MatTek Corporation in Ashland, USA. Day of delivery: 17. Dec. 2008 batch: 121108TTA, 120408WDA, 11219

Vehicle:

water

Details on test system:

Commercially available Epi-200-Kit.
The EpiDermTM tissue consists of normal, human-derived epidermal keratinocytes which have been cultured to form a multi-layered, 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 EpiDermTM tissues are cultured on specially prepared cell cultures inserts.Four 6-well-plates were prepared with 0.9 mL assay medium in each well. The inserts containing the tissues were transferred to the wells using sterile forceps and the 6-well-plates were set into the incubator at 37°C and 5% CO2 for one hour (pre-incubation). For each experiment (“three minutes” and “one hour”), one 24-well-plate was prepared as holding plate. 12 wells of each plate were filled with 300 μL assay medium, the other 12 with 300 μL MTT medium. One additional plate was left empty. The plates were stored in the incubator. For each experiment (“three minutes” and “one hour”), two 6-well-plates were used. After pre-incubation, the assay medium was replaced by fresh assay medium and the test was started, using two wells as negative control with 50 μL H2O demin., two wells as positive controls with 50 μL potassium hydroxide solution and two other wells for testing the test item. Solid test items were ground, and 25 mg test item were applied together with 25 μL H2O. At the begin of each experiment (application of negative controls), a stop watch was started. After the respective incubation time, the inserts were removed from the plates using sterile forceps. The inserts were thoroughly rinsed with PBS, blotted with sterile cellulose tissue and set into the respective holding plate, using the wells containing assay medium.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

25 mg test item were applied together with 25 μL Water.

Duration of treatment / exposure:

3 minutes and 1 hour

Number of replicates:

2

Test system

Vehicle:

water

Results and discussion

In vitro

Results

Results 1

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

3 minutes

Value:

ca. 87.8

Negative controls validity:

valid

Positive controls validity:

valid

Results 2

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

1 hour

Value:

ca. 76.8

Negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

After treatment with the test item, the relative absorbance values were reduced to 87.8% after three minutes treatment. This value is above the threshold for corrosivity (50%). After one hour treatment, the relative absorbance values were reduced to 76.8%. Lying, above the threshold for corrosivity (15%). Therefore the test item is considered as not corrosive. The negative control was within the normal range (criterion OD > 0.8), showing an OD of
2.134 (3 min.) resp. 2.050 (1 hour). The positive control showed a clear corrosive effect, with value of the three-minuteexperiment being 23.2% and value of the one-hour-experiment being 11.3%.

Executive summary:

One valid experiment was performed. Two tissues of the human skin model EpiDermTM were treated with the test item for three minutes and one hour, respectively. 25 mg of the solid test item were applied to each tissue and spread to match the tissue size. Deionised water was used as negative control, 8m KOH was used as positive control. After treatment with the negative control the absorbance values were well above the required acceptability criterion of mean OD > 0.8 for both treatment intervals thus showing the quality of the tissues. After treatment with the test item, the relative absorbance values were decreased to 87.8 % after three minutes treatment. This value is well above the threshold for corrosion

potential (50%). After one hour treatment, relative absorbance values were reduced to 76.8 %. This value, too, is well above the threshold for corrosion potential (15%). Therefore, 5-Aminotetrazol Potassium is considered as “not corrosive in the Human Skin Model Test”.