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Diss Factsheets

Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study without detailed documentation

Data source

Reference
Reference Type:
other: Body responsible for the test
Title:
Unnamed
Year:
1996

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
EU Method B.6 (Skin Sensitisation)
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
A Guinea pig maximisation test was available

Test material

Constituent 1
Chemical structure
Reference substance name:
N-methyl-4-(p-formylstyryl)pyridinium methylsulfate
EC Number:
418-240-3
EC Name:
N-methyl-4-(p-formylstyryl)pyridinium methylsulfate
Cas Number:
74401-04-0
Molecular formula:
C16H17NO5S
IUPAC Name:
4-[2-(4-formylphenyl)ethenyl]-1-methylpyridin-1-ium methyl sulfate
Test material form:
solid: particulate/powder

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal
Vehicle:
water
Remarks:
Distilled water
Concentration / amount:
1% w/v
Route:
intradermal
Vehicle:
other: Mixture of Freund's Complete Adjuvant plus distilled water (1:1)
Concentration / amount:
1% w/v
Route:
other: epicutaneous
Vehicle:
water
Remarks:
distilled
Concentration / amount:
75% w/w
Challenge
No.:
#1
Vehicle:
water
Remarks:
distilled water
Concentration / amount:
a) 75% (w/w)
b) 50% (w/w)
No. of animals per dose:
Number of animals in test group: 10
Number of animals in negative control group: 5
Positive control substance(s):
no

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
75 %
No. with + reactions:
8
Total no. in group:
10
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
50 %
No. with + reactions:
9
Total no. in group:
10
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
75 %
No. with + reactions:
5
Total no. in group:
10
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
50 %
No. with + reactions:
5
Total no. in group:
10
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
75 %
No. with + reactions:
0
Total no. in group:
5
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
50 %
No. with + reactions:
0
Total no. in group:
5
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
75 %
No. with + reactions:
0
Total no. in group:
5
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
50 %
No. with + reactions:
0
Total no. in group:
5

Any other information on results incl. tables

Maximum concentration not causing irritating effects in preliminary test: 10 %

 

Signs of irritation during induction:

Intradermal Induction: well-defined erythema observed in all animals during induction. No adverse effects were noted in the control group.

Topical Induction: yellow coloured staining was noted at the induction sites of all test group animals at the 1 and 24-hour observations.The staining did not affect evaluation of skin responses. Very slight to well-defined erythema observed in all animals during induction. No adverse effects were noted in the control group.

 

Evidence of sensitisation of each challenge concentration: 9/10.

 

Other observations:

Yellow-coloured staining was commonly noted at the challenge sites of test and control group animals at the 24 and 48-hour observations. The staining did not affect evaluation of skin responses.

75% w/w in Distilled water: Positive skin responses (erythema grades 1-2) were seen in 8 test animals at 24 hours (including an incident of very slight oedema in one animal) and in 5 test animals at 48 hours. Desquamation was noted at the challenge site of one test animal at 48 hours.

50% w/w in Distilled water: Positive skin responses (erythema grade 1-2) were seen in 9 test animals at 24 hours (including an incident of very slight oedema in one animal) and in 5 test animals at 48 hours. Desquamation was noted at the challenge site of two test animals at 48 hours.

No skin reaction were seen in any control animals at either challenge concentration.

Applicant's summary and conclusion

Interpretation of results:
other: The test substance is classified as sub-category 1A skin sensitiser according to the CLP Regulation EC No. 1272/2008.
Conclusions:
> 60 % of the animals showed a positive response upon an intradermal induction with the test item at 1 % w/v.
Executive summary:

The skin sensitisation potential of the test substance was evaluatedin vivoin a maximisation test on Guinea pigs according to the EU Method B.6 (92/69/EEC) and in compliance with GLP.

More than 60 % of the animals showed a positive response upon an intradermal induction with the test item at 1 % w/v.

The susbtance is considered as a skin sensitiser