Registration Dossier

Administrative data

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:
weight of evidence
Study period:
From April 23 to June 15, 1979.
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Internationally accepted guideline, well documented and scientifically acceptable.
Principles of method if other than guideline:
The optimization test was used, an intracutaneous sensitization procedure exceeding the sensitivity of the method recommended in the "Appraisal of the Safety of, Chemicals in Foods, Drugs and Cosmetics" (1959), the US Association of Food and Drug Officials (AFDO).
GLP compliance:
no
Remarks:
Pre GLP.
Type of study:
Maurer optimisation test
Justification for non-LLNA method:
Valid test available
Species:
guinea pig
Strain:
Pirbright-Hartley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: test laboratory.
- Age at study initiation: ca 10 weeks old.
- Weight at study initiation: between 280 to 390 grams.
- Housing: housed individually in Macrolon cages type 3.
- Diet: ad libitum standard guinea pig pellets - NAFAG, No. 830, Gossau SG.
- Water: ad libitum.
- Acclimation period: the animals were acclimatized for 10 days.

ENVIRONMENTAL CONDITIONS
- Temperature: 20 ± 1 °C
- Humidity: 55 ± 5 %
- Photoperiod: 14 hours light cycle day.
Route:
intradermal
Vehicle:
other: intradermal: physiological saline; epidermal: vaseline PhH VI.
Concentration / amount:
0.1% for intradermal application.
30% for epidermal application.
Route:
intradermal and epicutaneous
Vehicle:
other: intradermal: physiological saline; epidermal: vaseline PhH VI.
Concentration / amount:
0.1% for intradermal application.
30% for epidermal application.
No. of animals per dose:
1 male and 10 female guinea pigs.
Details on study design:
A. INDUCTION EXPOSURE
- No. of exposures: one injection every second day (except weekends) to a total of 10 intracutaneous injections of a freshly prepared solution.
- Control group: one control group was treated with the vehicle alone ("negative control").
- Site: on the first day, injections of 0.1 ml were administered into the shaven skin of the right flank and the back, while on the following days a single intracutaneous injection was given into the back.
During the second and third week of the induction period the test material was incorporated in a mixture of the normal vehicle with complete Bacto Adjuvant.

B. CHALLENGE EXPOSURE
Intradermal
- First challenge injection: fourteen days after the last sensitizing injection.
- Site: administered into the skin of the left flank.
- Observation: 24 hours after each injection during the first week of the induction period and 24 hours after the challenge injection the reactions were recorded.
- Evaluation/scoring system: the two largest perpendicular diameters (in mm) and the increase in the skin- fold thickness (in mm) were measured and by multiplication of these values "reaction volume" was obtained (in µl) for each reading from each animal. The mean volume plus one standard deviation of the induction reactions observed in the individual animal in the first week was taken as representing the skin irritation "threshold" for each animal. Any challenge reaction greater than this threshold value in the induction period was graded as an allergic reaction and the animal termed "positive". The number of "positive" animals in the test group was compared with the number of animals in the control group (treated with the vehicle alone) that showed a non-specific reaction of at least the same magnitude ("negative , control").

Epicutaneous
- Application: 10 days after the intracutaneous challenge injection.
- Dose: subirritant dose of the test compound: 30 % in vaseline.
- Route: test substance was applied epicutaneously under occlusive dressings.
- Duration/exposure: 24 hours.
- Scoring system: the reactions were evaluated 24 h after removing of the bandages according the Draize scoring scale.
Reading:
other: Incidence of positive animals per group after intradermal challenge injection.
Group:
test group
Dose level:
0.1 %
No. with + reactions:
16
Total no. in group:
20
Remarks on result:
other: Reading:
Reading:
other: Incidence of positive animals per group after occlusive epicutaneous application.
Group:
test group
Dose level:
30 %
No. with + reactions:
2
Total no. in group:
20
Remarks on result:
other: Reading:

Intradermal injection of the vehicle alone failed to induce sensitization.

Incidence of positive animals per group after intradermal challenge injection.

N. of positive animals/N. treated animals P
Vehicle control 0/20
Test substance 16/20 < 0.01

Incidence of positive animals per group after occlusive epicutaneous application.

N. of positive animals/N. treated animals P
Vehicle control 0/20
Test substance 2/20 > 0.01

Challenge reactions after occlusive epicutaneous administration of the test material.

Erythema score (Draize Score) 24 hours after removal of the dressing.

Animal N. males 681 682 683 684 685 686 687 688 689 690
Score 0 0 0 1 0 0 2 0 0 0
Animal N. females 691 692 693 694 695 696 697 698 699 700
Score 0 0 0 0 0 0 0 0 0 0

Reaction volumes (µl) after intradermal injection of test substance.

Animal identification number Induction (mean + s) after skin sensitization  + = positive reactor
Application N.  Mean Standard deviation
1 2 3 4
681 M 0 0 0 0 0 0 0 0 -
682 M 0 0 0 0 0 0 0 32 +
683 M 0 0 0 0 0 0 0 9 +
684 M 0 0 0 0 0 0 0 224 +
685 M 0 0 0 0 0 0 0 65 +
686 M 0 0 9 0 2.3 4.5 6.8 64 +
687 M 0 0 0 0 0 0 0 62 +
688 M 0 0 0 0 0 0 0 6 +
689 M 0 0 0 0 0 0 0 18 +
690 M 0 0 0 0 0 0 0 7 +
691 F 0 0 0 0 0 0 0 72 +
692 F 0 0 0 0 0 0 0 0 -
693 F 0 0 0 0 0 0 0 0 -
694 F 0 0 0 0 0 0 0 79 +
695 F 0 0 0 0 0 0 0 45 +
696 F 0 0 0 0 0 0 0 112 +
697 F 0 0 0 0 0 0 0 315 +
698 F 0 0 0 0 0 0 0 13 +
699 F 5 0 0 0 1.3 2.5 3.8 170 +
700 F 0 0 0 0 0 0 0 0 -
Goup mean 0.3 0 0.5 0 64.7 16/20

Reaction volumes (µl) after intradermal injection of physiological saline.

Animal identification number Induction (mean + s) after skin sensitization  + = positive reactor
Application N.  Mean Standard deviation
1 2 3 4
641 M 0 0 0 0 0 0 0 0 -
642 M 0 0 0 0 0 0 0 0 -
643 M 0 0 0 0 0 0 0 0 -
644 M 0 0 0 0 0 0 0 0 -
645 M 0 0 0 0 0 0 0 0 -
646 M 0 0 0 0 0 0 0 0 -
647 M 0 0 0 0 0 0 0 0 -
648 M 0 0 0 0 0 0 0 0 -
649 M 0 0 0 0 0 0 0 0 -
650 M 0 0 0 0 0 0 0 0 -
651 F 0 0 0 0 0 0 0 0 -
652 F 0 0 0 0 0 0 0 0 -
653 F 0 0 0 0 0 0 0 0 -
654 F 0 0 0 0 0 0 0 0 -
655 F 0 0 0 0 0 0 0 0 -
656 F 0 0 0 0 0 0 0 0 -
657 F 0 0 0 0 0 0 0 0 -
658 F 0 0 0 0 0 0 0 0 -
659 F 0 0 0 0 0 0 0 0 -
660 F 0 0 0 0 0 0 0 0 -
Goup mean 0 0 0 0 0 0/20
Interpretation of results:
not sensitising
Remarks:
Migrated information according to the CLP Regulation Criteria used for interpretation of results: EU
Conclusions:
Intradermal injection of the vehicle alone failed to induce sensitization.
Executive summary:

Method

The optimization test was used, an intracutaneous sensitization procedure exceeding the sensitivity of the method recommended in the "Appraisal of the Safety of, Chemicals in Foods, Drugs and Cosmetics" (1959), the US Association of Food and Drug Officials (AFDO).

Results

Intradermal injection of the vehicle alone failed to induce sensitization.

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

Two studies were conducted on the substance to be registered (CAS 16324-27-9), according to internationally accepted testing guidelines pre-GLP. Results are consistent and indicate no concern for skin sensitisation potential.

Within the whole category, nine over fourteen registered substances covering at least one member per group (see data matrix in the Category Justification Report attached to the section 13 of the dossier) was tested and none of the existing tests arisen any concern for skin sensitisation.

All substances of the category were modelled with OECD Toolbox and the provisional results about sensitisation and protein binding were calculated for all members: no alerts were reported for any substance. As it can be noted, the influence of the variability in functional group is very low, more related to the variability in the polarity of the substance than on potential reactivity that can arise a concern. As it can be noted, the influence of the variability in functional group is very low, more related to the variability in the polarity of the substance than on potential reactivity that can arise a concern. From a metabolic point of view, an estimation with OECD Toolbox of the dermal metabolism was also performed, in order to verify if breakdown products may be formed. Skin adsorption is considered the condition for sensitisation to express, therefore no concern for sensitisation properties can be expected for all members of the category (see Category Justification Report, attached to the Section 13).

The same was performed for CAS 16324-27-9, and a common behaviour regarding this end point within the category was observed. Based on all those considerations the available studies on the analogous substances are representative for the substance under registration that can then be considered not sensitizing.

Migrated from Short description of key information:

Non sensitizing.

Justification for selection of skin sensitisation endpoint:

Two studies have been conducted according to internationally accepted testing guidelines pre-GLP. Results are consistent and indicate no concern for skin sensitisation potential.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available

Justification for classification or non-classification

According to CLP Regulation (EC1272/2008), 3.4 Respiratory or skin sensitisation section, skin sensitizer means a substance that will lead to an allergic response following skin contact.

The criteria to classify a substance as skin sensitizer, on the basis of results from test animals, are reported into the second adaptation to technical progress* a substance in considered a skin sensitizer when:

- an adjuvant type test method for skin sensitisation is used and a response of at least 30 % of the animals is considered as positive;

- for a non-adjuvant Guinea pig test method a response of at least 15% of the animals is considered positive;

- a stimulation index of three or more is considered a positive response in the local lymph node assay.

Under the experimental conditions employed, 0 % of the animals of the test group showed skin reactions 24 and 48 hours after removing the dressings.

In conclusion,the available experimental data are adequate for classification and labelling according to CLP Regulation (EC 1272/2008) and the results show that the substance is not classified as skin sensitizer.

*Commission Regulation (EU) No 286/2011 of 10 March 2011, amending, for the purposes of its adaptation to technical and scientific progress, Regulation (EC) No 1272/2008 of the European Parliament and of the Council on classification, labelling and packaging of substances and mixtures.