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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

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Diss Factsheets

Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
December 1981
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1982
Report date:
1982

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: following the Journal Officiel de la République Française of 21/1/71 and 8/6/73
Principles of method if other than guideline:
The method is similar to OECD guidelines, but the exposure is under occlusive patch and and duration is 24 hours.
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
2-thienylacetic acid
EC Number:
217-639-8
EC Name:
2-thienylacetic acid
Cas Number:
1918-77-0
Molecular formula:
C6H6O2S
IUPAC Name:
2-(thiophen-2-yl)acetic acid

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: no data
- Age at study initiation: nodata
- Weight at study initiation: between 2.5 and 3.5 kg
- Housing:kept in individual in cages measuring 540x360x315 mm or in restraining devices which allow the back of the animal to be treated.
- Diet: 150 g per animal per day
- Water: ad libitum
- Acclimation period: no data

ENVIRONMENTAL CONDITIONS
- Temperature: minimum 20°C
- Humidity: no data
- Air changes: 12 times per hour
- Photoperiod: 12 hrs dark / 12 hrs light

IN-LIFE DATES: treatment on 22 December 1981

Test system

Type of coverage:
occlusive
Preparation of test site:
other: clipped and abraded/non-abraded
Vehicle:
unchanged (no vehicle)
Controls:
no
Amount / concentration applied:
TEST MATERIAL
- Amount(s) applied: 0.5 mL
Duration of treatment / exposure:
24 hours
Observation period:
72 hours
Number of animals:
6
Details on study design:
TEST SITE
- Area of exposure: right (scarified) and left flanks
- % coverage: 2 cm²
- Type of wrap if used: impregnated gauze maintained with an occlusive patch (Neodermotest roc) consisting of a central circular disc of 22 mm diameter with a surrounding adhesive, perfored plaster 10 mm wide.

REMOVAL OF TEST SUBSTANCE
- Washing: no

OBSERVATION TIME POINTS
24 and 72 hours

SCORING SYSTEM:
- Method of calculation: as in the guideline

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
erythema score
Basis:
mean
Remarks:
normal/scarified
Time point:
24 h
Score:
2
Max. score:
4
Reversibility:
not reversible
Remarks on result:
not determinable
Remarks:
the greenish color of the product makes the reading impossible in 2 animals. The whitish color of the skin makes the reading impossible in 4 rabbits. 3 rabbits gives a score of 2.
Irritation parameter:
erythema score
Basis:
mean
Remarks:
normal skin
Time point:
72 h
Score:
>= 1 - <= 2
Max. score:
4
Reversibility:
not reversible
Remarks on result:
other: score readable in 5 animals (the greenish color makes the reading impossible in 1 animal). individual scores: 2/2/1/2/1 (mean value 1.6)
Irritation parameter:
erythema score
Basis:
mean
Remarks:
scarified
Time point:
72 h
Score:
2
Max. score:
4
Reversibility:
not reversible
Remarks on result:
other: score readable in 3 animals (the greenish color makes the reading impossible in 2 animals, the whitish color of skin makes the reading impossible in 1 animal). individual scores: 2/2/2 (mean value 2)
Irritation parameter:
edema score
Basis:
mean
Remarks:
normal
Time point:
24 h
Score:
2.33
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Remarks on result:
positive indication of irritation
Remarks:
individual scores: 4/2/1/3/2/2
Irritation parameter:
edema score
Basis:
mean
Remarks:
normal
Time point:
72 h
Score:
1
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Remarks on result:
positive indication of irritation
Remarks:
individual scores: 2/1/1/1/1/0
Irritation parameter:
edema score
Basis:
mean
Remarks:
scarified
Time point:
24 h
Score:
2.5
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Remarks on result:
positive indication of irritation
Remarks:
individual scores: 4/4/1/2/2/2
Irritation parameter:
edema score
Basis:
mean
Remarks:
scarified
Time point:
72 h
Score:
1.83
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Remarks on result:
positive indication of irritation
Remarks:
individual scores: 2/2/1/3/1/2
Irritation parameter:
erythema score
Basis:
mean
Remarks:
normal skin
Time point:
24/48/72 h
Score:
ca. 1.8
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Irritation parameter:
erythema score
Basis:
mean
Remarks:
scarified
Time point:
24/48/72 h
Score:
ca. 2
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Irritation parameter:
edema score
Basis:
mean
Remarks:
normal skin
Time point:
24/48/72 h
Score:
ca. 1.67
Max. score:
4
Reversibility:
not fully reversible within: 72 hours
Irritation parameter:
edema score
Basis:
mean
Remarks:
scarified
Time point:
24/48/72 h
Score:
ca. 2.17
Max. score:
4
Reversibility:
not fully reversible within: 72 hours

Applicant's summary and conclusion

Interpretation of results:
Category 2 (irritant) based on GHS criteria
Conclusions:
In this study in rabbits, the substance is considered as irritant to the skin after a 24-hour exposure.
Executive summary:

In a primary dermal irritation study, NZW rabbits (6 males) were dermally exposed to 0.5 mL of undiluted 2-thienylacetic acid for 24 hours under occlusion (on both flanks, one was abraded).  Animals then were observed for 3 days.  Irritation was scored by the method of Draize.

The greenish color of the product makes the reading of erythema scores impossible in several animals. For others the whitish color of the skin makes also reading not possible.

The mean scores observed were:

- normal skin at 24h: 2 for erythema and 2.33 for edema

- normal skin at 72h: 1.6 for erythema and 1.0 for edema

- scarified skin at 24h: 2 for erythema and 2.5 for edema

- scarified skin at 72h: 2 for erythema and 1.83 for edema

Complete reversibility is not observed after 72 hours.

Even if some tests conditions deviate from the current standards (24-hour exposure and occlusive), 2-thienylacetic acid can be considered as irritant according to CLP criteria.