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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:
experimental study
Adequacy of study:
key study
Study period:
1996
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Selection criteria for dose selection were not clear. reliability was assessed in the Risk Assessment Report under the Existing substances Regulation.
Qualifier:
no guideline available
Principles of method if other than guideline:
see: any other information on materials and methods
GLP compliance:
no
Type of study:
guinea pig maximisation test
Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
male/female
Details on test animals and environmental conditions:
Six male and four female Albino Dunkin/Hartley guinea pigs (weight 316-350 g)
Route:
intradermal
Vehicle:
other: 0.01% dodecylbenzene sulphonate in 0.9% saline (DOBS/saline) for the intradermal induction injection, 70% acetone / 30% polyethylene glycol 400 (aceton/PEG400) for the challenge patch.
Concentration / amount:
Intradermal injection: 0.5% Galaxolide 50 (equivalent to 0.325% HHCB) in vehicle (0.01% dodecylbenzene sulphonate in 0.9% saline (DOBS/saline))
Induction patch: 100% Galaxolide 50 (equivalent to 65% HHCB)
Challenge patch: 25% Galaxolide 50 (equivalent to 16.25% HHCB) in vehicle (70% acetone / 30% polyethylene glycol 400 (aceton/PEG400))
Route:
epicutaneous, occlusive
Vehicle:
other: 0.01% dodecylbenzene sulphonate in 0.9% saline (DOBS/saline) for the intradermal induction injection, 70% acetone / 30% polyethylene glycol 400 (aceton/PEG400) for the challenge patch.
Concentration / amount:
Intradermal injection: 0.5% Galaxolide 50 (equivalent to 0.325% HHCB) in vehicle (0.01% dodecylbenzene sulphonate in 0.9% saline (DOBS/saline))
Induction patch: 100% Galaxolide 50 (equivalent to 65% HHCB)
Challenge patch: 25% Galaxolide 50 (equivalent to 16.25% HHCB) in vehicle (70% acetone / 30% polyethylene glycol 400 (aceton/PEG400))
No. of animals per dose:
10
Details on study design:
1st application: Induction 0.5 % intracutaneous
2nd application: Induction 100 % occlusive epicutaneous
3rd application: Challenge 25 % occlusive epicutaneous
Challenge controls:
Eight animals were treated as controls and received induction and challenge treatments similar to the test pigs minus the test material.
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
25% Galaxolide
No. with + reactions:
2
Total no. in group:
10
Clinical observations:
very faint erythema (score 0.5)
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25% Galaxolide. No with. + reactions: 2.0. Total no. in groups: 10.0. Clinical observations: very faint erythema (score 0.5).
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
25% Galaxolide
No. with + reactions:
3
Total no. in group:
10
Clinical observations:
very faint erythema (score 0.5)
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25% Galaxolide. No with. + reactions: 3.0. Total no. in groups: 10.0. Clinical observations: very faint erythema (score 0.5).
Reading:
rechallenge
Group:
test group
Dose level:
25% Galaxolide
Total no. in group:
10
Remarks on result:
other: Reading: rechallenge. Group: test group. Dose level: 25% Galaxolide. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
25% Galaxolide
No. with + reactions:
3
Total no. in group:
10
Clinical observations:
very faint erythema (Score 0,5)
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25% Galaxolide. No with. + reactions: 3.0. Total no. in groups: 10.0. Clinical observations: very faint erythema (Score 0,5).
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
25% Galaxolide
No. with + reactions:
1
Total no. in group:
10
Clinical observations:
very faint erythema (score 0,5)
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25% Galaxolide. No with. + reactions: 1.0. Total no. in groups: 10.0. Clinical observations: very faint erythema (score 0,5).
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
25% Galaxolide
No. with + reactions:
1
Total no. in group:
10
Clinical observations:
very faint erythma (score 0,5)
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 25% Galaxolide. No with. + reactions: 1.0. Total no. in groups: 10.0. Clinical observations: very faint erythma (score 0,5).
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
25% Galaxolide
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 25% Galaxolide. No with. + reactions: 0.0. Total no. in groups: 10.0.

At 24 hours, very faint erythema (score 0.5) was found in 2/10 animals at challenge 1, 3/10 animals at challenge 2, and 1/10 at challenge 3. At 48 hours, 3/10, 1/10 and 0/10 had very faint erythema. At challenge at 24 hours, only one animal showed very faint erythema to faint erythema.

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Except for one equivocal response in one animal, no evidence that the material was a sensitiser was seen. Classification: not sensitizing
Executive summary:

Galaxolide (65% HHCB in DEP) has been subjected to a non-GLP guinea pig maximization test. The used doses of Galaxolide were 0.5% in 0.01% dodecylbenzene sulphonate in 0.9% saline (DOBS/saline) for the intradermal injection, 100% for the induction patch, and 25% in 70% acetone/30% polyethylene glycol 400 (acetone/PEG400) for the challenge patch. These doses were selected based on preliminary irritation tests using 0.1, 0.25, 0.5, 1.0 and 2.0% Galaxolide concentrations for intradermal injections, however the selection criteria were not clear. The actual concentrations of HHCB are 0.325%, 65%, and 16.25%, respectively. Ten (six male, four female) Albino Dunkin/Hartley guinea pigs (weight 316-350g) were tested on a 2cm x 4cm area of skin in the dorsal shoulder area, clipped free of fur. Induction consisted of a 0.1 ml intradermal injection of 0.325% HHCB in DOBS/saline and 0.1 ml 50% Freund’s Complete Adjuvant in 0.9% saline. This was followed one week later by a 48 hr occluded patch (filter paper attached by adhesive tape to polythene backing) saturated with 65% HHCB). The patch was applied at the same 2 cm by 4cm area after freshly shaving the skin. Challenge applications were made 14 days later at a freshly shaved naïve site by saturation of an 8mm diameter filter paper patch with 16.25% HHCB in 70% acetone/30% PEG 400. Eight animals were treated as controls and received induction and challenge treatments similar to the test pigs minus the test material. Two repeat challenges at weekly intervals were conducted. At 24 hours, very faint erythema (score 0.5) was found in 2/10 animals at challenge 1, 3/10 animals at challenge 2, and 1/10 at challenge 3. At 48 hours, 3/10, 1/10 and 0/10 had very faint erythema. At challenge at 24 hours, only one animal showed very faint erythema to faint erythema. Except for one equivocal response in one animal, no evidence that the material was a sensitiser was seen (Basketter, 1996).

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

Skin sensitisation

Key study: Galaxolide (65% HHCB in DEP) has been subjected to a non-GLP guinea pig maximization test. The used doses of Galaxolide were 0.5% in 0.01% dodecylbenzene sulphonate in 0.9% saline (DOBS/saline) for the intradermal injection, 100% for the induction patch, and 25% in 70% acetone/30% polyethylene glycol 400 (acetone/PEG400) for the challenge patch. These doses were selected based on preliminary irritation tests using 0.1, 0.25, 0.5, 1.0 and 2.0% Galaxolide concentrations for intradermal injections, however the selection criteria were not clear. The actual concentrations of HHCB are 0.325%, 65%, and 16.25%, respectively. Ten (six male, four female) Albino Dunkin/Hartley guinea pigs (weight 316-350g) were tested on a 2cm x 4cm area of skin in the dorsal shoulder area, clipped free of fur. Induction consisted of a 0.1 ml intradermal injection of 0.325% HHCB in DOBS/saline and 0.1 ml 50% Freund’s Complete Adjuvant in 0.9% saline. This was followed one week later by a 48 hr occluded patch (filter paper attached by adhesive tape to polythene backing) saturated with 65% HHCB). The patch was applied at the same 2 cm by 4cm area after freshly shaving the skin. Challenge applications were made 14 days later at a freshly shaved naïve site by saturation of an 8mm diameter filter paper patch with 16.25% HHCB in 70% acetone/30% PEG 400. Eight animals were treated as controls and received induction and challenge treatments similar to the test pigs minus the test material. Two repeat challenges at weekly intervals were conducted. At 24 hours, very faint erythema (score 0.5) was found in 2/10 animals at challenge 1, 3/10 animals at challenge 2, and 1/10 at challenge 3. At 48 hours, 3/10, 1/10 and 0/10 had very faint erythema. At challenge at 24 hours, only one animal showed very faint erythema to faint erythema. Except for one equivocal response in one animal, no evidence that the material was a sensitiser was seen (Basketter, 1996).

 

Additional information: In a GLP compliant study, Galaxolide (65% HHCB in DEP) was tested for its allergenic and photoallergenic potential in 12 albino Hartley strain guinea pigs (418 to 487 g) with Freund's adjuvant injection. Dermal induction (1% Galaxolide (65% HHCB in DEP)) was performed twice (second induction after 24hr), once including adjuvant injections, one excluding adjuvant injections. After 25 min, the sites were exposed to ultraviolet light. A control group was included. Ten to 14 days after induction, a challenge with 1, 0.3 or 0.1% Galaxolide in ethanol (actual HHCB concentrations 0.65%, 0.2%, and 0.065%) by dermal application. Thirty min later, the animals were irradiated as above, after which the test material was applied to fresh sites to check for contact sensitivity, and the sites scored at 24 and 48 hr. A second challenge was carried out 6 or 7 days later. In 1/12 a very faint trace of erythema was found at 1.0% and 0.3% Galaxolide with UVA at challenge 1 and 2. Under the conditions of the study, Galaxolide is not a photosensitiser in guinea pigs. (Parish, 1988)

Additionally, several human studies are available, which have been summarized in the table below.

 

Study type

Number tested

Concentration of HHCB

Patch details

Result

Reference

HRIPT

40

3.75% Galaxolide in alcohol

Semi-occlusive, 9 applications of 24 hr each

Negative

Rubenkoenig and, 1994

HRIPT

43

100%, 50% Galaxolide in alcohol SDA39CI

Semi-occlusive, 8-9 applications of 24 hr each

Negative

Guillaume et al, 1973a

HRIPT

42

100% neat HHCB, no vehicle

Semi-occlusive, 8-9 applications of 24 hr each

Negative

Guillaume et al, 1973b

Maximisation

10

65% HHCB in DEP, vehicle-petrolatum

Occlusive, 48-hr patch on 5 alternate days

Negative

Epstein, 1974

Maximisation

24

65% HHCB in DEP, vehicle-petrolatum

Occlusive, 48-hr patch on 5 alternate days

Negative

Epstein, 1979

Patch testing in patients

179

25% Galaxolide in petrolatum

Silver Patch Testers

Negative, 3/179 false positives

DeGroot et al, 1985

Patch testing in patients

28

3% Galaxolide in petrolatum

Occlusive patches

Negative

Meynadier et al, 1986

Patch testing in patients

100

1 and 5% Galaxolide 50 in petrolatum

Finn Chambers

Negative

Frosch et al, 1995

Photosensitisation

27

25% HHCB in vehicle ethanol/DEP 75:25

Occlusive – 24 hr patches

Negative

Mills, 1997

 

 

Conclusion and discussion: Although some questionable elicitation reactions have been reported as a result of patch tests in dermatological clinics on sensitive patients, the available data with guinea pigs and humans (HRIPT and maximization tests) provide no evidence of potential for induction of sensitisation for HHCB. HHCB need not be classified as a skin contact sensitiser. There is no evidence from studies in experimental animals or with humans, that HHCB is a photosensitiser.

No further testing is deemed necessary.

 

(Summary in line with EU-RAR, 2008)


Migrated from Short description of key information:
Skin sensitisation:
- guinea pig maximisation test: not sensitising (no guideline available)

Justification for selection of skin sensitisation endpoint:
One Guinea Pig Maximization Test is available which was performed under acceptable conditions, although no OECD guideline was followed and the study was not performed under GLP-conditions.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)
Additional information:

The respiratory sensitisation of the substance is assessed using the integrated evaluation strategy for respiratory sensitisation data in the ECHA guidance (R7A, Fig. 7.3-2). As the substance is a non sensitiser, it is unlikely to be a respiratory sensitiser as presented in the ECHA guidance.


Migrated from Short description of key information:
Integrated evaluation strategy for respiratory sensitisation data (ECHA guidance R7A, Fig. 7.3-2): no respiratory sensitisation

Justification for selection of respiratory sensitisation endpoint:
No studies are available, therefore the respiratory sensitisation of the substance is assessed using the integrated evaluation strategy for respiratory sensitisation data in the ECHA guidance (R7A, Fig. 7.3-2).

Justification for classification or non-classification

Based on the available skin sensitisation studies, HHCB does not have to be classified for skin sensitisation in accordance with the criteria outlined in Annex VI of 67/548/EEC (DSD) and Annex I of 1272/2008/EC (CLP).

Based on the integrated evaluation strategy for respiratory sensitisation data in the ECHA guidance, HHCB is not considered to be a respiratory sensitiser.