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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:
data from handbook or collection of data
Justification for type of information:
data is from peer reviewed journals

Data source

Referenceopen allclose all

Reference Type:
other: Authoritative data base
Title:
HSDB for the CAS- 99-57-0
Author:
U.S National Library of Medicine
Year:
2011
Bibliographic source:
HSDB (Hazardous Substances Data Bank); US national Library of Medicine reviewed by SRC, 2011
Reference Type:
publication
Title:
An animal model assessment of common dye-induced allergic contact dermatitis
Author:
JOE DINARDO, Raleigh N, C; and ZOE DIANA DRAELOS
Year:
2007
Bibliographic source:
JOURNAL OF COSMETIC SCIENCE, 58, 209-214 May/June 2007

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: Buehler test a modification of the Buehler and the Klecak method for open epicutaneous testing (OET)
Principles of method if other than guideline:
Skin sensitisation of the test chemical was evaluated using a modification of the Buehler and the Klecak method for open epicutaneous testing (OET) in a guinea pig model
GLP compliance:
not specified
Type of study:
open epicutaneous test
Justification for non-LLNA method:
Currently no LLNA study is available for assessment. The Guinea Pig Maximization Test (GPMT) has been carried out as an animal test to predict human sensitization for over a decade and is recommended by international test guidelines such as OECD.

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 2-amino-4-nitrophenol
- Molecular Formula: C6H6N2O3
- Molecular Weight: 154.125 g/mol
- SMILES Notation: C1=CC(=C(C=C1[N+](=O)[O-])N)O
- InChI: 1S/C6H6N2O3/c7-5-3-4(8(10)11)1-2-6(5)9/h1-3,9H,7H2
- Substance type: Organic
- Physical state: solid

In vivo test system

Test animals

Species:
guinea pig
Strain:
not specified
Sex:
not specified

Study design: in vivo (non-LLNA)

Induction
Route:
epicutaneous, open
Vehicle:
propylene glycol
Concentration / amount:
0.1 ml of test chemical [10% in propylene glycol]
Day(s)/duration:
3 times weekly(Monday, Wednesday , Friday) for 3 weeks
Adequacy of induction:
not specified
Challenge
No.:
#1
Route:
epicutaneous, open
Vehicle:
propylene glycol
Concentration / amount:
10%, 5%,2.50% in propylene glycol
Day(s)/duration:
single
Adequacy of challenge:
not specified
No. of animals per dose:
10 albino guinea pigs
Details on study design:
Details on study design
RANGE FINDING TESTS: no data available

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures:3 times weekly(Monday, Wednesday , Friday)
- Exposure period:3 weeks
- Test groups: Yes
- Control group:No
- Site:Left flank shaved albino guinea pigs
- Frequency of applications:3 times weekly
- Duration:3 weeks
- Concentrations:0.1 ml of 10 % test chemical in propylene glycol

B. CHALLENGE EXPOSURE
- No. of exposures:Once
- Day(s) of challenge:After 2 weeks of rest period from induction exposure
- Exposure period: No data available
- Test groups: Yes
- Control group: No
- Site:Right flank of shaved guinea pig
- Concentrations:10,5 and 2.5 % of the induction concentration
- Evaluation (hr after challenge):24-hrs

OTHER: All test sites were graded for erythema and edema 24 and 48 hours post-application using a four-point ordinal scale
0 = no reaction,
1 -- slight reaction,
2 = moderate reaction,
3 = severe reaction
Challenge controls:
no data available
Positive control substance(s):
yes
Remarks:
0.5% of 2,4-dinitrochlorobenzene (DNCB) in ethanol was included for both the induction and challenge phases

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
10% in propylene glycol
Total no. in group:
10
Clinical observations:
80% animals exhibited a positive allergic reactions
Remarks on result:
positive indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
5% in propylene glycol
Total no. in group:
10
Clinical observations:
70% animals exhibited a positive reaction
Remarks on result:
positive indication of skin sensitisation
Key result
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
2.50% in propylene glycol
Total no. in group:
10
Clinical observations:
40% animals exhibited a positive reaction
Remarks on result:
positive indication of skin sensitisation

Any other information on results incl. tables

Table 1: Allergic contact dermatitis of dyes

CAS number

Chemical class

Induction concentration in propylene glycol

Challenge concentration in propylene glycol*

10%

5%

2.5%

99-57-0

nitroaminophenol

10%

+(80%)

+(70%)

+(20%)

 

Table 2: Dose-response of dyes eliciting positive response at 10% concentration

CAS number

Chemical class

Induction concentration in propylene glycol

Challenge concentration in propylene glycol*

1%

0.5%

0.25%

99-57-0

nitroaminophenol

1%

+(30%)

Negative

Negative

*results expressed as negative or positive (+) with percent of animals in the group demonstrating an allergic reaction in parenthesis

Applicant's summary and conclusion

Interpretation of results:
other: sensitizing
Conclusions:
Since a positive response was observed in the challenge exposure at 10% challenge exposure, the test chemical was re-tested using a 1% induction exposure and challenge concentrations of 1.0%, 0.5%, and 0.25%.
The test chemical produced a positive reaction at 10% challenge exposure, also in the retest at 1% challenge concentration, but no reactions were noted at 0.5 and 0.25% challenge concentrations.
Hence, it was considered that the test chemical was positive sensitizer in guinea pigs.
Executive summary:

A modified Buehler and Klecak method for open epicutaneous testing[OET] was performed to assess the sensitization potential of the test chemical.

The test chemical was tested at an induction concentration of 10% and challenge concentrations of 10.0%, 5.0%, and 2 .5% in propylene glycol.

During the induction phase, the left flanks of ten albino guinea pigs were shaved and the dye test material applied three times weekly (Monday, Wednesday, Friday) for three consecutive weeks. Each animal received 0.1 ml of the dye test material over a 1.8-cm circular area. Following the induction period, the guinea pigs entered the challenge phase. The challenge phase began after a two-week rest period when the right flank of each guinea pig was shaved and exposed to three different dye test material concentrations in propylene glycol(10.0%, 5.0%, and 2 .5%). Twenty-four hours after the last induction and challenge application, the animals were depilated to clearly observe dermal reactions.

All test sites were graded for erythema and edema 24 and 48 hours post-application using a four-point ordinal scale.A positive control of 0.5% 2,4-dinitrochlorobenzene(DNCB) in ethanol was included for both the induction and challenge phases.

Since a positive response was observed in the challenge exposure at 10% challenge exposure, the test chemical was re-tested using a 1% induction exposure and challenge concentrations of 1.0%, 0.5%, and 0.25%.

The test chemical produced a positive reaction at 10% challenge exposure, also in the re-test at 1% challenge concentration, but no reactions were noted at 0.5 and 0.25% challenge concentrations.

Hence, it was considered that the test chemical was positive sensitizer in guinea pigs.