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Administrative data

Description of key information

In a skin sensitisation Local Lymph Node Assay (LLNA) according to OECD TG 429 using the substance oligomerisation and alkylation reaction products of 2-phenylpropene and phenol (OAPP), a SI of 2.68 was observed for the 3 % preparation. SI for the 30 % preparation was 16.35. An EC3 of 3.63 % was determined by linear interpolation between the 3 % and 30 % data points. Based on this data, OAPP is considered to be a moderate skin sensitiser.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records
Reference
Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Qualifier:
according to
Guideline:
EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)
GLP compliance:
yes (incl. certificate)
Type of study:
mouse local lymph node assay (LLNA)
Specific details on test material used for the study:
- Name of test material (as cited in study report): Novares LA 300 (phenol, methylstyrenated)
- Lot/batch No.: 28166
- Composition of test material: composition is specified in IUCLID Sect. 13 - Assessment reports under Certificate of Analysis_Novares LA 300_phenol, methylstyrenated
- Stability under test conditions: no measured data; based on chemical structure assumed to be stable
- Storage condition of test material: room temperature, exclusion of light
Species:
mouse
Strain:
Balb/c
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Breeding farm VELAZ s.r.o., Koleč u Kladna, Czech Republic
- Age at study initiation: 8 - 10 wks
- Weight at study initiation: 17 - 19 g
- Housing: macrolon cages
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +- 3
- Humidity (%): 30 – 70
- Photoperiod (hrs dark / hrs light): 12 / 12

Vehicle:
other: DAE 433
Concentration:
mixture of 40% dimethylacetamide, 30% acetone and 30% ethanol
No. of animals per dose:
5
Details on study design:
RANGE FINDING TESTS:
- Compound solubility: dispersion
- Irritation: no
- Lymph node proliferation response: not examined


MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Criteria used to consider a positive response:
Stimulation index (SI) is ≥ 3
Response increases in dose-related manner
Criteria for irritation potential: individual and mean ear weight


TREATMENT PREPARATION AND ADMINISTRATION:
Days 1-3: 25 µL test suspension in DAE 433 , 1x on day 1, 2, and 3
Days 4 and 5: no treatment
Day 6: Injection of 250 μL of phosphate-buffered saline (PBS) containing 7.5 x105 Bq (c. 21 µCi) of 3H-methyl thymidine
into all test and control mice via the tail vein. Five hours later, the animals were killed.



Positive control substance(s):
other: DNCB (dinitrochlorbenzene, 0.5% (w/v) solution)
Statistics:
Non-parametric Kruskal-Wallis test, and then the non-parametric two-group Mann-Whitney rank test (probability level 0.05) was applied to all two-group comparisons [using software Statgraphic ® Centurion (version XV, USA)].
Key result
Parameter:
EC3
Value:
3.63
Parameter:
SI
Value:
2.36
Test group / Remarks:
0.3% test substance in vehicle; 5 animals
Parameter:
SI
Value:
2.68
Test group / Remarks:
3% test substance in vehicle; 5 animals
Parameter:
SI
Value:
16.35
Test group / Remarks:
30% test substance in vehicle; 5 animals

Table 1: Individual and mean radioactivity in cell suspensions (Report Table 4)

Activity (DPM)

Animal No.

NC

(1-5)

PC

(6-10)

30%

(11-15)

3%

(16-20)

0.3%

(21-25)

1

550.98

11374.69

9354.53

1425.77

1232.24

2

485.39

10401.94

9984.31

1475.60

1484.48

3

568.93

10347.82

11634.71

1367.08

1128.80

4

526.30

8837.38

9107.79

1301.28

1222.94

5

596.74

9493.34

4517.77

1748.67

1091.42

 Group

mean

545.67

10091.03

8919.82

1463.68

1231.98

SI

1.00

18.49

16.35

2.68

2.26

NC = vehicle control; PC = positive control

Table 2: Individual and average ear weights (Report Table 5)

Weight of ear biopsies (milligrams)

Animal No.

NC

(1-6)

PC

(7-12)

30%

(13-18)

3%

(19-24)

0.3%

(25-30)

1

24.5

27.4

32.7

25.0

21.8

2

25.2

27.5

28.4

23.0

23.1

3

23.8

26.5

34.2

21.4

21.4

 4

23.4

26.7

29.4

21.5

21.0

5

24.7

27.2

41.2

21.7

25.0

 Group mean

24.32

27.06*

33.18*

22.52

22.46

SD

0.72

0.44

5.07

1.53

1.62

NC = vehicle control; PC = positive control

* statistically significant with p =< 0.05, Mann-Whitney test

Table 3:  Summary table (Report Table 6)

Group

Radioisotope incorporation

in lymph nodes

Ear weight

Mean DPM

SI

Mean (mg)

NC

545.67

1.0

24.32

PC

10091.03

18.49+

27.06

30%

8919.82

16.35+

33.18

3%

1463.68

2.68

22.52

0.3%

1231.98

2.26

22.46

Bold figures with + = values >= 3

Interpretation of results:
Category 1B (indication of skin sensitising potential) based on GHS criteria
Conclusions:
In this LLNA according to OECD TG 429, an EC3 of 3.63 was determined for the substance oligomerisation and alkylation reaction products of 1-phenylpropene and phenol. Resulting EU/GHS classification is skin sensitising Cat. 1B (EC3 > 2).
Endpoint conclusion
Endpoint conclusion:
adverse effect observed (sensitising)
Additional information:

In a mouse local lymph node assay according to OECD TG 429 performed under GLP conditions using 0.3, 3, and 30 % preparations of the test substance in vehicle (mixture of 40 % dimethylacetamide, 30 % acetone, and 30 % ethanol), an increase of the Stimulation Index (SI) for the test groups over controls was observed (SI = 2.26, 2.68, and 16.35). For a concentration of 30 % the SI was > 3 demonstrating a sensitising response of the test animals following the treatment with test substance. The mean ear weight was below (0.3 and 3 % test group, 22.46 and 22.52 mg, respectively) and above (30 % test group = 33.18 mg) the ear weight of the controls (24.32 mg). The SI > 3 for the 30 % test group indicates a sensitising potential for OAPP (Brabnikova/VUOS 2010). An EC3 of 3.63 can be calculated by linear interpolation between the data points 3 % and 30 % indicating a moderate skin sensitising potential.

Based on the positive results of the mouse LLNA (Brabnikova/VUOS 2010), OAPP is rated as a potential contact allergen.

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

There is no data for respiratory sensitisation.

Justification for classification or non-classification

The substance oligomerisation and reaction products of 2-phenylpropene and phenol showed a skin sensitising effect in a mouse LLNA test. EC3 was determined to be > 2% (3.63%). According to Regulation (EC) No 1272/2008, the substance is classified as skin sensitising Cat 1B, H317.

There is no data to support respiratory sensitisation as such. No classification is required under Regulation (EC) No 1272/2008.