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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:
weight of evidence
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

Reference
Reference Type:
publication
Title:
Final Report on the Safety Assessment of Disperse Black 9
Author:
Cosmetic Ingredient Review Expert Panel
Year:
1986
Bibliographic source:
JOURNAL OF THE AMERICAN COLLEGE OF TOXICOLOGY, Volume 5, Number 3, 1986

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: Kligman-Magnusson procedure
Principles of method if other than guideline:
The dermal sensitization potential of Disperse Black 9 was assessed in guinea pigs using the Kligman – Magnusson procedure
GLP compliance:
not specified
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
Name of the test chemical: 2,2'-[[4-[(4-aminophenyl)azo]phenyl]imino]bisethanol
Common Name: Disperse Black 9
Molecular Formula: C16H20N4O2
Molecular Weigth:300.36 g/mol
Substance Type:Organic
Physical State: Solid (orange powder)
Specific details on test material used for the study:
Name of the test chemical: 2,2'-[[4-[(4-aminophenyl)azo]phenyl]imino]bisethanol
Common Name: Disperse Black 9
Molecular Formula: C16H20N4O2
Molecular Weigth:300.36 g/mol
Substance Type:Organic
Physical State: Solid (orange powder)

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
female

Study design: in vivo (non-LLNA)

Induction
Route:
intradermal and epicutaneous
Vehicle:
petrolatum
Concentration / amount:
Intradermal exposure:
Three pairs of injections (0.05 ml each) were administered intradermally- Freund’s complete adjuvant (in equal parts water), 0.1% Disperse Black 9, and a mixture of equal parts of the adjuvant and dye.
Epicutaneous, occlusive: One week later – 48 hours occlusive 25% Disperse Black 9 in petrolatum
Day(s)/duration:
48 hours
Adequacy of induction:
not specified
Challenge
No.:
#1
Route:
epicutaneous, occlusive
Vehicle:
propylene glycol
Concentration / amount:
25% Disperse Black 9 in propylene glycol
Day(s)/duration:
48 hours
Adequacy of challenge:
not specified
No. of animals per dose:
10 female Hartley guinea pigs
Details on study design:
RANGE FINDING TESTS:No data available

MAIN STUDY
A. INDUCTION EXPOSURE
(intradermal exposure)
- No. of exposures: Three pairs of intradermal injections
- Exposure period:no data
- Test groups:10
- Control group:No data available
- Site: intrascapular region
- Frequency of applications:No data available
- Duration:No data available
- Concentrations: Three pairs of injections (0.05 ml each) were administered intradermally- Freund’s complete adjuvant (in equal parts water), 0.1% Disperse Black 9, and a mixture of equal parts of the adjuvant and dye

(Epicutaneous, occlusive)
- No. of exposures: single
- Exposure period: 48 hours
- Test groups: 10 female Hartley guinea pigs
- Control group: no data
- Site: intrascapular area
- Frequency of applications: single
- Duration: 48 hours
- Concentrations: 25% Disperse Black 9 in petrolatum

B. CHALLENGE EXPOSURE
- No. of exposures: single
- Day(s) of challenge:No data available
- Exposure period:No data available
- Test groups:10 guinea pigs
- Control group:No data available
- Site: flank
- Concentrations: 25% Disperse Black 9 in propylene glycol
- Evaluation (hr after challenge): Sites were evaluated 24, 48, and 72 hours after patch removal.

OTHER: no data available
Challenge controls:
no data available
Positive control substance(s):
not specified

Results and discussion

In vivo (non-LLNA)

Results
Reading:
1st reading
Hours after challenge:
48
Group:
test group
Dose level:
25% Disperse Black 9 in propylene glycol
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
Skin sensitizing effects were not observed.
Remarks on result:
no indication of skin sensitisation

Applicant's summary and conclusion

Interpretation of results:
other: not sensitizing
Conclusions:
No signs of dermal sensitization were observed on female guinea pig skin at any time point after challenge exposure.
Hence, Disperse Black 9 was considered to be not sensitizing to guinea pig skin.
Executive summary:

The dermal sensitization potential of Disperse Black 9 was assessed in guinea pigs using the Kligman – Magnusson procedure.10 female Hartley guinea pigs were used for the study.

Three pairs of injections (0.05 ml each) were administered intradermally into the shaved interscapular area of each guinea pig: Freund’s complete adjuvant (in equal parts water), 0.1% Disperse Black 9, and a mixture of equal parts of the adjuvant and dye. One week later, the sites were shaved again, and a 48-h occlusive patch containing 25% Disperse Black 9 in petrolatum was applied. Two weeks later, an occlusive challenge patch containing 25% Disperse Black 9 in propylene glycol was applied to the shaved flank of each guinea pig. Sites were evaluated 24, 48, and 72 hours after patch removal.

No signs of dermal sensitization were observed on female guinea pig skin at any time point after challenge exposure.

Hence,Disperse Black 9 was considered to be not sensitizing to guinea pig skin.