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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:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
When Potassium oxide is hydrated is produced Potassium hydroxide. Therefore, the health effects of Potassium hydroxide need to be considered in the assessment of Potassium oxide In 2004 and 2006, new guidelines on in vitro tests were published (OECD TG 430, 431 and 435) . The described method is meeting the criteria required by the new OECD TG 431 guideline.

Data source

Reference
Reference Type:
publication
Title:
The ECVAM international validation study on in vitrol tests for skin corrosivity. 2. Results and evaluation by the management team.
Author:
Fentem JH, Archer GEB, Balls M, BothamPA, Curren RD, Earl LK, Esdaile DJ, Holzhütter HG and LIebsch M
Year:
1998
Bibliographic source:
Toxicol. In Vitro, 12, 483-524

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
other: OECD TG 431 (In vitro skin corrosion: human skin model test), study was performed prior to the adoption of the test guideline
Principles of method if other than guideline:
The Skin² model ZK1350 : in vitro skin corrosion test
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): potassium hydroxideWhen Potassium oxide is hydrated is produced Potassium hydroxide. Therefore, the health effects of Potassium hydroxide need to be considered in the assessment of Potassium oxide.When water is added to Potassium oxide, Potassium hydroxide is produced.K2O+H2O→KOH

Test animals

Species:
other: Three-dimensional human skin equivalent
Details on test animals and environmental conditions:
SKIN MODEL
- Skin² model ZK1350
- type: human kertinocytes, multi-layered (epidermal, dermal and corneal layers) and fully differentiated
- medium: serum-free, chemically defined
- vessel: polycarbonate filter inserts
- shipment conditions: inserts embedded in agarose gel containing nutrient solution

Test system

Type of coverage:
open
Preparation of test site:
not specified
Vehicle:
unchanged (no vehicle)
Controls:
other: positive (8 N KaOH) and negative (blank) controls
Amount / concentration applied:
TEST MATERIAL
- Amount applied: 15 µl
- Concentration (if solution): 5% and 10%
Duration of treatment / exposure:
10 sec
Observation period:
60 min
Number of animals:
four replicates per test substance
Details on study design:
TEST PROTOCOL:
- temperature: 18-22°C
- pre-incubation period: 2h
- washing: yes, PBS
- extraction: with isopropanol
SCORING SYSTEM:
- endpoint: metabolic conversion
- observation method: metabolic reduction of MTT (yellow stain), determined by spectrophotometer
- scoring: relative viability of cells (percentage of viability of the negative controls)
- classification:
"highly corrosive" (R35) if relative cell viability < 10 %
"corrosive" (R34) if relative cell viability >10- 80%
"non corrosive" if relative cell viability > 80%

Results and discussion

In vitro

Results
Irritation / corrosion parameter:
other:
Value:
4
Remarks on result:
other:
Remarks:
Basis: other: Skin² model ZK1350 in vitro skin corrosion test. Time point: no data. Max. score: 4.0. Reversibility: no data. Remarks: 10% KOH is classified as corrosive, 5% KOH is classified as non corrosive. (migrated information)

In vivo

Irritant / corrosive response data:
10% KOH is classified as "corrosive" (R34), 5% KOH as non corrosive based on the Skin² ZK1350 in vitro skin corrosion test.
this is the result of a validation study. The model failed to identify 57% of chemicals that are known to be corrosive (low sensitivity of the model).

Applicant's summary and conclusion

Interpretation of results:
corrosive
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
10% KOH is classified as "corrosive" (R34), 5% KOH as non corrosive using The Skin² model ZK1350