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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Administrative data

Description of key information

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
1970
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Meets generally accepted scientific standards, well documented and acceptable for assessment; pre-GLP study.
Qualifier:
no guideline followed
Principles of method if other than guideline:
Guinea Pig induction method, company protocol
GLP compliance:
no
Type of study:
skin painting test
Species:
guinea pig
Strain:
not specified
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Weight at study initiation: mean 441.2 g
Route:
epicutaneous, open
Vehicle:
other: acetone
Concentration / amount:
Induction: 20% (2 applications); 50% (8 applications)
Challenge: 5%,
Rechallenge: 20%
Route:
epicutaneous, open
Vehicle:
other: acetone
Concentration / amount:
Induction: 20% (2 applications); 50% (8 applications)
Challenge: 5%,
Rechallenge: 20%
No. of animals per dose:
10
Details on study design:
MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 10 applications
- Test groups: 10 animals
- Control group: 3 animals
- Site: ca. 25 cm2 clipped area of flank
- Frequency of applications: paintings were done three times in a row, for 5 days per week (together ten times in two weeks)
- Concentrations: 20% (2 applications), 50% (8 applications)


B. CHALLENGE EXPOSURE
- No. of exposures: 2
- Day(s) of challenge: first challenge 16 days after induction; second challenge 16 days after first challenge
- Test groups: 10 animals
- Control group: 3 animals
- Site: shaved right flank
- Concentrations: 5% (challenge), 20% (rechallenge)
- Evaluation (hr after challenge): 12 h
Challenge controls:
Not treated during induction period
Positive control substance(s):
not specified
Reading:
1st reading
Hours after challenge:
12
Group:
test chemical
Dose level:
5%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 12.0. Group: test group. Dose level: 5%. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
rechallenge
Hours after challenge:
12
Group:
test chemical
Dose level:
20%
No. with + reactions:
7
Total no. in group:
10
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 12.0. Group: test group. Dose level: 20%. No with. + reactions: 7.0. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
12
Group:
negative control
Dose level:
5%
No. with + reactions:
0
Total no. in group:
3
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 12.0. Group: negative control. Dose level: 5%. No with. + reactions: 0.0. Total no. in groups: 3.0.
Reading:
rechallenge
Hours after challenge:
12
Group:
negative control
Dose level:
20%
No. with + reactions:
0
Total no. in group:
3
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 12.0. Group: negative control. Dose level: 20%. No with. + reactions: 0.0. Total no. in groups: 3.0. 
The test substance was judged to be slightly sensitizing by the authors.

1) Induction:
Repeated application of the test substance at 20% or 50% in acetone  
produced hemorrhagic encrustations in 10/10 animals of the test group.  
These symptoms were reversible within the 16-day rest period.

2) Challenge / rechallenge:
Single application of the 5% solution in acetone to the previously  
untreated site did not produce any skin response in the animals of the  
test group. In contrast, application of the 20% solution at 16 days later  
produced a slight erythema in 7/10 test animals. Control animals did not  
show any skin response after treatment with either 5% or 20%.
Interpretation of results:
sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

The experimental data for hydroquinone is not provided. It is referred to the legal classification of hydroquinone in the EU (Annex I index no. 604 -005 -00 -4).


Migrated from Short description of key information:
Both trimethylhydroquinone (CAS 700-13-0) and hydroquinone (CAS 123-31-9) cause skin sensitization in experimental animals. Therefore, 2-methylhydroquinone is classified for skin sensitization without further testing.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification