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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin irritation: 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:
2020

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)
GLP compliance:
yes (incl. QA statement)

Test material

1
Chemical structure
Reference substance name:
9-oxo-9H-thioxanthene-4-carboxylic acid
EC Number:
849-175-2
Cas Number:
51762-56-2
Molecular formula:
C14H8O3S
IUPAC Name:
9-oxo-9H-thioxanthene-4-carboxylic acid

In vitro test system

Test system:
human skin model
Source species:
other: human epidermis
Details on animal used as source of test system:
The test system is a commercially available EpiDermTM-Kit, procured by MatTek.
The EpiDermTM tissue consists of 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 representing main
lipid classes analogous to those found in vivo. The EpiDermTM tissues are cultured on specially prepared cell culture inserts
Control samples:
yes, concurrent negative control
yes, concurrent positive control
Duration of treatment / exposure:
44 hours and 5 minutes
Duration of post-treatment incubation (if applicable):
19 hours and 25 minutes
Number of replicates:
3

Test system

Amount / concentration applied:
1 replicate 24.8 mg
2 replicate 24.8 mg
3 replicate 24.9 mg
Duration of treatment / exposure:
44 hours and 5 minutes
Number of animals:
3

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
tissue 1
Value:
97.9
Negative controls validity:
valid
Positive controls validity:
valid
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
tissue 2
Value:
96.6
Negative controls validity:
valid
Positive controls validity:
valid
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
tissue 3
Value:
101.8
Negative controls validity:
valid
Positive controls validity:
valid

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The test item 9-oxo-9H-thioxanthene-4-carboxylic acid is considered as non-irritant to skin.
After the treatment, the mean value of relative tissue viability was reduced to 98.8%. This value is above the threshold for skin irritation (50%).
The optical density of the negative control was well within the required acceptability crite-rion of 0.8 ≤ mean OD ≤ 2.8.
The positive control has met the acceptance criterion too, for thus ensuring the validity of the test system.
Variation within replicates was within the accepted range for negative control, positive control and test item (required: ≤ 18%).

For these reasons, the result of the test is considered valid.