5-octylbicyclo[2.2.1]hept-2-ene

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 to 20 November 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

TESTING PROPOSAL ON VERTEBRATE ANIMALS
[Please provide information for all of the points below. The information should be specific to the endpoint for which testing is proposed. Note that for testing proposals addressing testing on vertebrate animals under the REACH Regulation this document will be published on the ECHA website along with the third party consultation on the testing proposal(s).]

NON-CONFIDENTIAL NAME OF SUBSTANCE:
- Name of the substance on which testing is proposed to be carried out
- Name of the substance for which the testing proposal will be used [if different from tested substance]

CONSIDERATIONS THAT THE GENERAL ADAPTATION POSSIBILITIES OF ANNEX XI OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION [please address all points below]:
- Available GLP studies
- Available non-GLP studies
- Historical human data
- (Q)SAR
- In vitro methods
- Weight of evidence
- Grouping and read-across
- Substance-tailored exposure driven testing [if applicable]
- Approaches in addition to above [if applicable]
- Other reasons [if applicable]

CONSIDERATIONS THAT THE SPECIFIC ADAPTATION POSSIBILITIES OF ANNEXES VI TO X (AND COLUMN 2 THEREOF) OF THE REACH REGULATION ARE NOT ADEQUATE TO GENERATE THE NECESSARY INFORMATION:
- [free text]

FURTHER INFORMATION ON TESTING PROPOSAL IN ADDITION TO INFORMATION PROVIDED IN THE MATERIALS AND METHODS SECTION:
- Details on study design / methodology proposed [if relevant]

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

yes

Remarks:

The (minimum) temperature value (of 18.4°C) and the (minimum) relative humidity value (of 22%) were outside expected ranges of 19-25°C and 30-70%, The observed differences were considered to have had no adverse affect on results of the study.

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

5-octylbicyclo[2.2.1]hept-2-ene

EC Number:

814-965-8

Cas Number:

22094-84-4

Molecular formula:

C15H18 C15H26

IUPAC Name:

5-octylbicyclo[2.2.1]hept-2-ene

Test material form:

liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Materia; RP367_ONB-D
- Expiration date of the lot/batch: 09 August 2019
- Purity test date: 25 October 2017

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Controlled room temperature (15-25 °C, ≤ 70 Relative Humidity (%), under inert gas
- Stability under test conditions: Stable
- Solubility and stability of the test substance in the solvent/vehicle: No data
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: No data

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: None
- Preliminary purification step (if any): None
- Final dilution of a dissolved solid, stock liquid or gel: No
- Final preparation of a solid: not applicable

FORM AS APPLIED IN THE TEST (if different from that of starting material)

TYPE OF BIOCIDE/PESTICIDE FORMULATION (if applicable)

OTHER SPECIFICS:
- measurement of pH, osmolality, and precipitate in the culture medium to which the test chemical is added:
- other information:

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/CaOlaHsd

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Laboratory animal supplier
- Females: nulliparous and non-pregnant: yes
- Microbiological status of animals, when known:
- Age at study initiation: 12 weeks ± 1 week
- Weight at study initiation: 19.2 – 20.8 grams
(The weight variation in animals in the study did not exceed  20 % of the mean weight.)
- Housing: Group caging / mice were provided with glass tunnel-tubes
- Diet (ad libitum): ssniff® SM Rat/Mouse – Breeding and Maintenance, 15 mm, autoclavable “Complete feed for Rats and Mice – Breeding and Maintenance” (Batch number: 840 33675, Expiry date: January 2019 produced by ssniff Spezialdiäten GmbH (Ferdinand-Gabriel-Weg 16, D-59494 Soest, Germany), and Gel diet Transport (Batch Number: 60182180030101
- Water (ad libitum): Animals received tap water from the municipal supply from 500 mL bottles
- Acclimation period: 35 days
- Indication of any skin lesions: Only healthy animals were used for the study. Health status was certified by a veterinarian.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.4 - 23.7°C
- Humidity (%): 22 - 67 %
- Air changes (per hr): 15-20
- Photoperiod (hrs dark / hrs light): 12 hours daily, from 6.00 a.m. to 6.00 p.m.
- IN-LIFE DATES: From: To:

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

2,10 and 25%w/v

No. of animals per dose:

4

Details on study design:

PRE-SCREEN TESTS:
- Compound solubility: Ok
- Irritation: no data
- Systemic toxicity: no data
- Ear thickness measurements: yes
- Erythema scores: no

MAIN STUDY

ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method:
- Criteria used to consider a positive response:

TREATMENT PREPARATION AND ADMINISTRATION: During the study, animals were topically dosed with 25 µL of the appropriate formulation using a pipette on the dorsal surface of each ear. Each animal was dosed once a day for three consecutive days (Days 1, 2 and 3). There was no treatment on Days 4, 5 and 6.

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:

Test Group Name Measured DPM / group DPM Number of lymph nodes DPN Stimulation Index

Positive control
(25% (w/v) HCA
in AOO 64269 64228.5 8 8028.6 8.2

In vivo (LLNA)

Results

Results 1

Parameter:

SI

Value:

1

Test group / Remarks:

Negative control (AOO)

Results 2

Parameter:

SI

Value:

8.2

Test group / Remarks:

Positive control (25% (w/v) HCA in AOO

Results 3

Key result

Parameter:

SI

Value:

4.5

Test group / Remarks:

5-Octyl-2-Norbornene 25 (w/v)% in AOO

Results 4

Key result

Parameter:

SI

Value:

1.5

Test group / Remarks:

5-Octyl-2-Norbornene 10 (w/v)% in AOO

Results 5

Key result

Parameter:

SI

Value:

2

Test group / Remarks:

5-Octyl-2-Norbornene 2 (w/v)% in AOO

Cellular proliferation data / Observations:

CELLULAR PROLIFERATION DATA : given in table below.

DETAILS ON STIMULATION INDEX CALCULATION : Stimulation index (SI = DPN value of a treated group divided by the DPN value of the negative control group) for each treatment group was also calculated. A stimulation index of 3 or greater is an indication of a positive result.

EC3 CALCULATION : Stimulation index (SI = DPN value of a treated group divided by the DPN value of the negative control group) for each treatment group was also calculated. A stimulation index of 3 or greater is an indication of a positive result.

Since the test item gave a positive response, the EC3 value of the test item (EC3 means the effective chemical concentration required for SI=3) was calculated by linear interpolation according to the equation: EC3 = c + [(3-d)/(b-d)] x (a-c)


CLINICAL OBSERVATIONS:

BODY WEIGHTS: Marked body weight loss (≥5%) was observed for one animal of the 25% (w/v) dose group. However, the mean body weight change of this group was within the acceptable range and therefore considered as individual variability.
No test item related effects were observed on the mean body weight changes in the main study.

Any other information on results incl. tables

Test Group Name	Measured DPM / group	DPM	Number of lymph nodes	DPN	Stimulation Index
Background (5% (w/v) TCA)	39 42	-	-	-	-
Negative control (AOO)	7921	7880.5	8	985.1	1.0
5-Octyl-2-Norbornene 25 (w/v)% in AOO	35672	35631.5	8	4453.9	4.5
5-Octyl-2-Norbornene 10 (w/v)% in AOO	11701	11660.5	8	1457.6	1.5
5-Octyl-2-Norbornene 2 (w/v)% in AOO	15674	15633.5	8	1954.2	2.0
Positive control (25% (w/v) HCA inAOO	64269	64228.5	8	8028.6	8.2

Applicant's summary and conclusion

Interpretation of results:

Category 1B (indication of skin sensitising potential) based on GHS criteria

Conclusions:

In conclusion, under the conditions of the present assay, 5-Octyl-2-Norbornene, tested in a suitable vehicle, was shown to have sensitization potential (sensitizer) in the Local Lymph Node Assay. The calculated EC3 value of 5-Octyl-2-Norbornene is 17.5% (w/v).