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Administrative data

Description of key information

Skin sensitization: Guinea Pig (Buehler) study, comparable OECD 406,GLP

Mixture of N,N-dimethyldecanamide and N,N-dimethyloctanamide, (Stepan, 1990): not sensitising

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Referenceopen allclose all

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
March - April 1990
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Remarks:
Study according to Buehler protocol which satisfies the citeria of toxic control act (40 CFR) and the OECD Guideline, GLP, well documented
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Version / remarks:
Buehler test
Deviations:
no
GLP compliance:
yes
Type of study:
Buehler test
Justification for non-LLNA method:
The LLNA method was not established yet by the time the study was conducted.
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Lot/batch No.of test material: not specified

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

FORM AS APPLIED IN THE TEST (if different from that of starting material): diluted in 80% ethanol/ 20% distilled water (induction) or in acetone (challenge)
Species:
guinea pig
Strain:
Hartley
Remarks:
albino
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Murphy
- Weight: 374-623g
- Housing: individually
- Diet: ad libitum, PURINA GUINEA PIG CHOW
- Water: ad libitum
- Acclimation period: at least four days

ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): 12 / 12
Route:
epicutaneous, occlusive
Vehicle:
other: 80/20 ethanol/dest water
Concentration / amount:
5% (in 80/20 ethanol/dest water)
Route:
epicutaneous, occlusive
Vehicle:
other: acetone
Concentration / amount:
2.5% (in acetone)
No. of animals per dose:
Main study test group: 10 males and 10 females
Main study control group: 5 males and 5 females
Details on study design:
RANGE FINDING TESTS:
Irritation screening tests (pilots) with 8 male and 8 female animals were conducted. The several concentrations of the test substance (diluted in the same vehicle as used in the main study) were applied to the clipped skin of the animals backs (occlusive coverage). After approx. 6 h the chambers with the test solution were removed. 24 and 48 h after the treatment, the animals were examined for any irritating effects. Based on the results of these pilots a concentration of 5% test substance in 80% ethanol/ 20% distilled water, which caused slight to moderate patchy erythema, was used for the induction phase of the main study. As concentration for the challenge exposure, 2.5% test substance in acetone (highest non-irritating dose) was chosen.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 3
- Exposure period: approx. 6 h
- Frequency of applications: once a week
- Concentration: 5%

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 12 - 16 days after last induction exposure
- Exposure period: 6 h
- Test groups: 10 animals per gender
- Control group: 5 animals per gender
- Concentrations: 2.5%
- Evaluation (hr after challenge): 24hr + 48hr
Challenge controls:
5 animals per gender were used as control, no positive control is reported
Positive control substance(s):
no
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
2.5%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
2.5%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
2.5%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
2.5%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Interpretation of results:
GHS criteria not met
Conclusions:
Only slight reactions comparable to the controls were observed. The test substance is considered to be not sensitising.
Executive summary:

The potential of the test substance, as a 5% w/v formulation in 80% ethanol/20% distilled water, to produce delayed contact hypersensitivity in guinea pigs was evaluated using an adaptation of the method of Ritz and Buehler simialr to the OECD guideline 406

Following primary challenge, there were no grades of 1 produced in the test or control animals. The incidence of slight responses in the test group (13 of 20) was compared to that of the naive control group (7 of 10). The incidence and severity of these responses in the test group were essentially comparable to those produced by the naive control group indicating that sensitization had not been induced.

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
see attached RA justification
Reason / purpose for cross-reference:
read-across source
Reading:
1st reading
Hours after challenge:
24
Group:
test chemical
Dose level:
2.5%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
test chemical
Dose level:
2.5%
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
2.5%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
2.5%
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
no indication of skin sensitisation
Interpretation of results:
GHS criteria not met
Conclusions:
Only slight reactions comparable to the controls were observed. The test substance is considered to be not sensitising.
Executive summary:

The potential of a "analog test substance", as a 5% w/v formulation in 80% ethanol/20% distilled water, to produce delayed contact hypersensitivity in guinea pigs was evaluated using an adaptation of the method of Ritz and Buehler simialr to the OECD guideline 406

Following primary challenge, there were no grades of 1 produced in the test or control animals. The incidence of slight responses in the test group (13 of 20) was compared to that of the naive control group (7 of 10). The incidence and severity of these responses in the test group were essentially comparable to those produced by the naive control group indicating that sensitization had not been induced.

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

There are no valid in vivo studies of the skin sensitising potential for pure N,N-dimethyldecanamide. Nevertheless skin sensitisation was tested with a mixture of N,N-dimethyldecanamide and N,N-dimethyloctanamide (with traces of N,N-dimethyl-dodecanamide and N,N-dimethyl-hexanamide). Due to the fact that a high amount in the mixture was N,N-dimethyl-decanamide and the rest of the mixture are homologues with a lower and higher molecular weight which can be assumed to have a similar toxicological behaviour it is concluded that the mixture has an nearly similar toxicological behaviour like pure N,N-dimethyldecanamide, further details can be found in the attached RA justification in chapter 13.

Skin sensitisation:

A test with a mixture of N,N-dimethyldecanamide and N,N-dimethyloctanamide (with traces of N,N-dimethyldodecanamide and N,N-dimethylhexanamide) for skin sensitisation was done using an adaptation of the method of Ritz and Buehler* (Stepan 1990, J.J Kreuzmann). The test substance was used as 5% w/v formulation in 80% ethanol/20% distilled water for induction and as 2.5% formulation in acetone for challenge and epicutanueous occlusive applied to 20 guinea pigs. There were no grades of 1 produced in the test or control animals. The incidence of grade + responses in the test group (14 of 20) was compared to that of the naive control group (7 of 10). The incidence and severity of these responses in the test group were essentially comparable to those produced by the naive control group indicating that sensitization had not been induced. Therefore the mixture was classified as not sensitising.

* Study according to Buehler protocol which satisfies the criteria of toxic control act (40 CFR) and the OECD 406 Guideline, GLP.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

Migrated from Short description of key information:
no information available

Justification for classification or non-classification

Skin sensitisation:

Skin sensitisation was observed in a skin sensitisation guinea pig study (buehler protocol; mixture of dimethylalkylamides): The scores obtained from the study led to no classification for skin sensitisation according to GHS (Regulation (EU) 1272/2008) and also to no classification according to EU-criteria DSD (67/548/EEC). This classification was also supposed for the pure N,N-dimethyldecanamide as a large portion of the mixture was N,N-dimethyldecanamide (see discussion).

Respiratory sensitisation:

There are no data available to classify N,N-dimethyldecanamide as a sensitizer to respiratory system.

Labelling skin/respiratory sensitisation:

GHS: no classification

DSD: no classification