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Toxicological information

Skin irritation / corrosion

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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:
other: GLP Guideline Study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)
GLP compliance:
yes (incl. certificate)
Remarks:
Experimental Toxicology and Ecology, BASF SE, 67056 Ludwigshafen, Germany

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Hydroxyethylpiperazine mixture
- Physical state: liquid
- Analytical purity: 100%
- Composition of test material, percentage of components: ca. 40% 2-(piperazine-1-yl)ethanol, ca. 20% 1,4-piperazinediethanol, ca. 15% piperazine, ca. 25% water
- Lot/batch No.: R500 v. 15.10.2011
- Stability under storage conditions: The stability under storage conditions over the study period was guaranteed by the sponsor, and the sponsor holds this responsibility.
- Storage condition of test material: ambient temperature

Test animals

Species:
other: in vitro: EpiDerm
Strain:
other: not applicable

Test system

Type of coverage:
other: not applicable
Preparation of test site:
other: not applicable
Vehicle:
unchanged (no vehicle)
Controls:
other: not applicable
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 50 µL
Duration of treatment / exposure:
3 minutes at room temperature and 1 hour in the incubator (37°C)
Observation period:
not applicable
Number of animals:
not applicable
Details on study design:
Two tissues per exposure time (3 minutes at room temperature or 1 hour in the incubator, as a rule) and test group (test material, negative control (NC) and positive control (PC); 12 tissues per test) were used. In addition, one killed tissue per exposure time was treated with the test substance and NC, respectively, in order to detect direct MTT reduction. Control tissues were concurrently applied with 50 μL of de-ionized water (NC) or with 50 μL of 8 n potassium hydroxide (PC) or test substance (killed tissue control, KC).
Tissue destruction was determined by measuring the metabolic activity of the tissue after exposure using a colorimetric test. The reduction of mitochondrial dehydrogenase activity, measured by reduced formazan production after incubation with a tetrazolium salt (MTT) was chosen as endpoint. The formazan production of the test substance treated epidermal tissues is compared to that of negative control tissues. The quotient of the values indicates the relative tissue viability.

Acceptance criteria:
In case one of the below given acceptance criteria is not covered, repetition of the test was considered.
Assay acceptance criterion for the negative control (NC):
The absolute OD570 of the negative control tissues in the MTT test is an indicator of tissue viability obtained in the testing laboratory after the shipping and storing procedure and under specific conditions of the assay. Tissue viability is acceptable if the mean OD570 of the NC is ≥ 1.0. The mean OD570 of the NC should not exceed 2.5.

Assay acceptance criterion for the positive control (PC):
Potassium hydroxide as 8.0 normal ready made solution is used as positive reference. A 3-minute treatment with 8.0 n KOH usually reveals a mean relative tissue viability of ~20%. An assay is acceptable if mean relative tissue viability of the 3 min positive control is ≤ 30%.

Assay acceptance criterion for tissue variability:
For every treatment, except the killed controls, 2 tissues corrosion test are treated in parallel. The inter-tissue variability is considered to be acceptable if the difference of the OD570 values of the two tissues is ≤ 0.3 (corrosion test).

Assay acceptance criterion for killed controls (KC):
The OD570 of the killed control tissues treated as negative control should be ≤ 0.35.

Evaluation criteria:
Corrosive potential of the test materials is predicted from the mean relative tissue viabilities obtained after 3 min treatment compared to the negative control tissues concurrently treated with de-ionized water. A chemical is considered as "corrosive", if the mean relative tissue viability after 3 min treatment with a test material is decreased below 50%. In addition, those materials with a viability of ≥ 50% after 3 min treatment are considered as "corrosive" if the mean relative tissue viability after 1 hour treatment with a test material is decreased below 15%. Although the method is not finally validated for categorizing the severity of corrosivity according to certain classification and labeling systems, it is suggested to use the most stringent category for test substances leading to viabilities below 50% after 3 min treatment.

Results and discussion

In vivo

Irritant / corrosive response data:
After 3 minute exposure with the test substance the viability was 95% and after 1 hour 13%, respectively.

Any other information on results incl. tables

Results:

Exposure: 3 min

Exposure: 1 hour

Test substance

tissue 1

tissue 2

KC

mean

tissue 1

tissue 2

KC

mean

NC

mean OD570

1.918

1.922

0.187

1.92

1.93

1.774

0.176

1.852

viability

[% of NC]

99.9

100.1

-

100

104.2

95.8

-

100

test substance

mean OD570

1.821

1.831

0.191

1.826

0.233

0.235

0.195

0.234

viability

[% of NC]

94.8

95.4

-

95

12.6

12.7

-

13

PC

mean OD570

0.399

0.293

-

0.346

0.166

0.217

-

0.192

viability

[% of NC]

20.8

15.2

-

18

9.0

11.7

-

10

Due to the ability of the test substance to reduce MTT directly, a KC was applied in parallel.

However, the result of the KC did not indicate an increased MTT reduction (difference to KC of NC is not greater than 0.1). Thus the KC was not used for viability calculation.

Applicant's summary and conclusion

Interpretation of results:
corrosive
Remarks:
Migrated information