4,4'-isopropylidenediphenyl dicyanate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February - July 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

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:

4,4'-isopropylidenediphenyl dicyanate

EC Number:

214-590-4

EC Name:

4,4'-isopropylidenediphenyl dicyanate

Cas Number:

1156-51-0

Molecular formula:

C17H14N2O2

IUPAC Name:

4-{2-[4-(cyanooxy)phenyl]propan-2-yl}phenyl cyanate

Test material form:

other: flaked solidified melt

Details on test material:

- Physical state: see above
- Appearance: see above

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Test Substance Name: LZ 514
- Source: Lonza Ltd, Visp/Switzerland
- Lot/batch No. of test material: 5011
- Expiration date of the lot/batch: 2nd December 2017
- Manufacture date: 3rd December 2015

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage conditions: Controlled room temperature (15-25 ºC, below 70 RH%), protected from light and humidity.
- Stability under test conditions: stable
- Safety precautions: Routine safety precautions (lab coat, gloves, safety glasses, face mask) for unknown materials were applied to assure personnel health and safety.

In vivo test system

Test animals

Species:

mouse

Strain:

other: CBA/CaOlaHsd mice

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Envigo (formerly: Harlan Laboratories S.r.l.), San Pietro al Natisone (UD), Zona Industriale Azzida, 57, 33049 Italy
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: 9 weeks old (age-matched, within one week)
- Weight at study initiation: 20.2– 22.4 grams
- Housing: group caging / mice were provided with glass tunnel-tube
- Acclimation period: 13 days
- Indication of any skin lesions: no
- Water (e.g. ad libitum): tap water
- Diet (e.g. ad libitum): ssniff® SM Rat/Mouse – “Breeding & Maintenance, 15 mm, autoclavable Complete diet for rats/mice produced by ssniff Spezialdiäten GmbH (Ferdinand-Gabriel-Weg 16, D-59494 Soest, Germany)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.0 – 25.9°C
- Humidity (%): 24 - 79 %
- Air changes (per hr): 15-20 air exchanges/hour
- Photoperiod (hrs dark / hrs light): 12 hours daily, from 6.00 a.m. to 6.00 p.m.

Study design: in vivo (LLNA)

Vehicle:

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

Remarks:

abbreviated as AOO

Concentration:

Based on the observations recorded in the preliminary test, the 0.5% (w/v) dose was selected as top dose for the main test.

No. of animals per dose:

6 groups with 4 animals/group

Details on study design:

In the main assay, twenty four female CBA/CaOlaHsd mice were allocated to six groups of four animals each:
- four groups received test item (formulated in AOO) at 0.5 % (w/v), 0.25% (w/v), 0.1% (w/v) and 0.05% (w/v) concentrations,
- the negative control group received the vehicle (AOO),
- the positive control group received 25 % (w/v) HCA (dissolved in AOO).

Positive control substance(s):

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

Results and discussion

Positive control results:

The result of the positive control substance α-Hexylcinnamaldehyde (HCA) dissolved in the same vehicle was used to demonstrate the appropriate performance of the assay. The positive control substance was examined at a concentration of 25 % in the relevant vehicle (AOO) using CBA/CaOlaHsd mice.
No mortality, cutaneous reactions or signs of toxicity were observed for the positive control substance in the study. A lymphoproliferative response in line with historic positive control data (stimulation index value of 10.4) was noted for HCA in the main experiment. This value was considered to confirm the appropriate performance of the assay. Furthermore, the DPN values observed for the vehicle and positive control substance in this experiment were within the historical control. Each treated and control group included 4 animals.

In vivo (LLNA)

Results

Results 1

Key result

Parameter:

SI

Value:

12.6

Test group / Remarks:

test item concentration 0.5% (w/v)

Results 2

Key result

Parameter:

SI

Value:

16.5

Test group / Remarks:

test item concentration 0.25% (w/v)

Results 3

Key result

Parameter:

SI

Value:

4.1

Test group / Remarks:

test item concentration 0.1% (w/v)

Results 4

Key result

Parameter:

SI

Value:

4.7

Test group / Remarks:

test item concentration 0.05% (w/v)

Any other information on results incl. tables

No mortality or systemic clinical signs were observed during the main study. No test item precipitate was observed on the ears of the experimental animals. There were no indications of any irritancy at the site of application. No treatment related effects were observed on the mean body weight changes in the main study.

Applicant's summary and conclusion

Interpretation of results:

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

Conclusions:

The stimulation index values were 12.6, 16.5, 4.1 and 4.7 at concentrations of 0.5 % (w/v), 0.25% (w/v), 0.1% (w/v) and 0.05% (w/v), respectively. In conclusion, under the conditions of the present assay, LZ 514, tested in a suitable vehicle, was shown to have sensitization potential (sensitizer) in the Local Lymph Node Assay. Based on these results, the test item is classified as skin sensitizer Category 1 (sub-category 1A) according to the UN GHS system.

Executive summary:

The study was conducted as Local Lymph Node Assay according to testing methods OECD 429 and EC B. 42. The study was performed with vertebrate animals as no full regulatory in vitro alternative is available. Based on the observations recorded in the preliminary test, the 0.5% (w/v) dose was selected as top dose for the main test. In the main assay, twenty four female CBA/CaOlaHsd mice were allocated to six groups of four animals each at test item concentrations of 0.5 % (w/v), 0.25% (w/v), 0.1% (w/v) and 0.05% (w/v). Vehicle was acetone:olive oil 4:1.

The stimulation index values were 12.6, 16.5, 4.1 and 4.7 at concentrations of 0.5 % (w/v), 0.25% (w/v), 0.1% (w/v) and 0.05% (w/v), respectively. In conclusion, under the conditions of the present assay, LZ 514, tested in a suitable vehicle, was shown to have sensitization potential (sensitizer) in the Local Lymph Node Assay. Based on these results, the test item is classified as skin sensitizer Category 1 (sub-category 1A) according to the UN GHS system.