Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

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:
other: GLP status not stated; Well-documented, method employed consistent with OECD 406.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1978
Report date:
1978

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
GLP compliance:
not specified
Type of study:
Buehler test

Test material

Constituent 1
Chemical structure
Reference substance name:
6-hydroxy-2-naphthoic acid
EC Number:
240-759-7
EC Name:
6-hydroxy-2-naphthoic acid
Cas Number:
16712-64-4
Molecular formula:
C11H8O3
IUPAC Name:
6-hydroxynaphthalene-2-carboxylic acid
Constituent 2
Reference substance name:
6-HNA
IUPAC Name:
6-HNA
Details on test material:
- Name of test material (as cited in study report): HNA
- Physical state: Solid

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male/female
Details on test animals and environmental conditions:
A total of 45 animals (23 male; 22 female) were obtained for study.

TEST ANIMALS
- Source: Dutchland Breeding Farms; Denver, PA
- Age at study initiation: not stated
- Weight at study initiation: not stated
- Housing: Individually housed, type of housing not described.
- Diet (e.g. ad libitum): Base diet not described, fresh greens were used to supplement the diet.
- Water (e.g. ad libitum): not stated
- Acclimation period: not stated

ENVIRONMENTAL CONDITIONS
- not stated

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
peanut oil
Concentration / amount:
Test article was prepared as a suspension of 25% (w:v) 6-hydroxy-2-naphthoic acid in peanut oil. The preparation was blended to produce an homogenous suspension.
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
peanut oil
Concentration / amount:
Test article was prepared as a suspension of 25% (w:v) 6-hydroxy-2-naphthoic acid in peanut oil. The preparation was blended to produce an homogenous suspension.
No. of animals per dose:
Group 1 - Peanut Oil (Vehicle Control): 15 total (8M & 7F)
Group 2 - DCNB (Positive Control): 15 total (8M & 7F)
Group 3 - Test Article: 15 total (8M & 7F)
Details on study design:
Dosing Procedure:
- Sensitization Period: Test article application site was prepared (clipped free of hair) 24 hours prior to the initial dosing of each animal. All animals in all groups received 0.2 mL dosing solution applied to the back, on the right side of the spinal column below an "Elastopatch(R), with 3/4" x 1" Webril pad. The trunk of each animal was wrapped in an Elastoplast(R) bandage to occlude and secure the patches. After treatment, the animals were returned to their cages. Six hours after application, the bandages and patches were removed. Sensitization was performed three times a week for three weeks, for a total of 9 sensitizing exposures.

- Challenge Procedure: On the thirteenth day following the last Sensitization treatment, the treatment area of each animal was once again clipped free of hair and depilated with Neet(R). On the following day, all animals received the first challenge dose. However, in the challenge phase, two sites (one on either side of the spinal column) were treated. After 6 hours, both sites were evaluated for erythema and edema. Challenges were repeated at 24 and 48 hours.
Challenge controls:
As an additional control, a group of 5 unsensitized animals were treated with the test material.
Positive control substance(s):
yes
Remarks:
1-chloro-2,4-dinitrobenzene (DCNB)

Results and discussion

Positive control results:
DCNB (positive control) was a strong sensitizer in this study, confirming the susceptibility of this group of animals to dermal sensitization.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
6
Group:
negative control
Dose level:
Vehicle Control
No. with + reactions:
2
Total no. in group:
10
Clinical observations:
No edema observed in any animals; Very mild erythema observed in 2/10 animals. In one, erythema not bi-lateral, but persisted from 24 to 48 hours post-challenge. In other animal, erythema was bi-lateral, but only present at 24 hours post-challenge.
Remarks on result:
other: see Remark
Remarks:
Reading: 1st reading. . Hours after challenge: 6.0. Group: negative control. Dose level: Vehicle Control. No with. + reactions: 2.0. Total no. in groups: 10.0. Clinical observations: No edema observed in any animals; Very mild erythema observed in 2/10 animals. In one, erythema not bi-lateral, but persisted from 24 to 48 hours post-challenge. In other animal, erythema was bi-lateral, but only present at 24 hours post-challenge..
Reading:
1st reading
Hours after challenge:
6
Group:
positive control
Dose level:
1% DCNB in peanut oil
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Erythema observed in all animals; Mild edema observed in 1/10 animals
Remarks on result:
other: see Remark
Remarks:
Reading: 1st reading. . Hours after challenge: 6.0. Group: positive control. Dose level: 1% DCNB in peanut oil. No with. + reactions: 10.0. Total no. in groups: 10.0. Clinical observations: Erythema observed in all animals; Mild edema observed in 1/10 animals.
Reading:
1st reading
Hours after challenge:
6
Group:
test chemical
Dose level:
25% 6-hydrox-2-naphthoic acid in peanut oil
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
No observations of erythema or edema in any animals
Remarks on result:
other: see Remark
Remarks:
Reading: 1st reading. . Hours after challenge: 6.0. Group: test group. Dose level: 25% 6-hydrox-2-naphthoic acid in peanut oil. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: No observations of erythema or edema in any animals.
Reading:
rechallenge
Hours after challenge:
48
Group:
negative control
Dose level:
Vehicle Control
No. with + reactions:
4
Total no. in group:
10
Clinical observations:
No edema observed in any animal; 3 animals had single mild erythema obs, one-sided; One animal had bi-lateral erythema at 48 hours post Challenge 2.
Remarks on result:
other: see Remark
Remarks:
Reading: rechallenge. . Hours after challenge: 48.0. Group: negative control. Dose level: Vehicle Control. No with. + reactions: 4.0. Total no. in groups: 10.0. Clinical observations: No edema observed in any animal; 3 animals had single mild erythema obs, one-sided; One animal had bi-lateral erythema at 48 hours post Challenge 2..
Reading:
rechallenge
Hours after challenge:
48
Group:
positive control
Dose level:
1% DCNB in peanut oil
No. with + reactions:
10
Total no. in group:
10
Clinical observations:
Erythema (slight to well-defined) observed in all animals; Very slight to slight edema observed in 3/10 animals.
Remarks on result:
other: see Remark
Remarks:
Reading: rechallenge. . Hours after challenge: 48.0. Group: positive control. Dose level: 1% DCNB in peanut oil. No with. + reactions: 10.0. Total no. in groups: 10.0. Clinical observations: Erythema (slight to well-defined) observed in all animals; Very slight to slight edema observed in 3/10 animals. .
Reading:
rechallenge
Hours after challenge:
48
Group:
test chemical
Dose level:
25% 6-hydroxy-2-naphthoic acid in peanut oil
No. with + reactions:
2
Total no. in group:
10
Clinical observations:
One animal with a single, one-sided observation of very slight edema @ 24 hours post-challenge 2; one animal with single, one-sided observation of slight erythema at 24 hours post-challenge 2.
Remarks on result:
other: see Remark
Remarks:
Reading: rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 25% 6-hydroxy-2-naphthoic acid in peanut oil. No with. + reactions: 2.0. Total no. in groups: 10.0. Clinical observations: One animal with a single, one-sided observation of very slight edema @ 24 hours post-challenge 2; one animal with single, one-sided observation of slight erythema at 24 hours post-challenge 2..

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information Criteria used for interpretation of results: expert judgment
Conclusions:
Under the conditions of this study, no potential to produce dermal sensitization in the guinea pig was demonstrated by 6-HNA.
Executive summary:

No signs of systemic toxicity were noted in any animals during this study. Sporadic incidences of urinary and fecal staining of the abdomen, soft stool, piloerection, and animal thinness were noted during this study. There was no severe dermal response noted in any of the animals treated with 6 -HNA. The reactions following each challenge were similar for both control animals and those treated with 6 -HNA. DCNB (positive control) was a strong sensitizer in this study, confirming the susceptibility of this group of animals to dermal sensitization.

Under the conditions of this study, no potential to produce dermal sensitization in the guinea pig was demonstrated by 6 -HNA.