Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
20 January 2010 - 12 May 2010
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study was conducted according to OECD guideline 429 and under GLP conditions.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Deviations:
no
GLP compliance:
yes
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Phosphorous slag
- Physical state: Solid
- Analytical purity: Confidential information
- Expiration date of the lot/batch: Confidential information
- Stability under storage conditions: Stable
- Storage condition of test material: At room temperature in the dark

In vivo test system

Test animals

Species:
mouse
Strain:
other: CBA/J
Sex:
female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River France, L'Arbrescle Cedex, France
- Age at study initiation: Approx. 9 weeks
- Weight at study initiation: Within +/- 20% of the sex mean
- Housing: Individually, according to guideline
- Diet (e.g. ad libitum): Ad libitum, pelleted rodent diet
- Water (e.g. ad libitum): Ad libitum, tap water
- Acclimation period: At least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.0-23.4
- Humidity (%): 39-65
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (LLNA)

Vehicle:
propylene glycol
Concentration:
0% (vehicle), 10%, 25% and 50%
No. of animals per dose:
5
Details on study design:
RANGE FINDING TESTS:
- Concentration: 25% and 50% (maximum concentration in accordance with test guideline)
- Irritation: Erythema (score: 1) was noted in both ears of the tested animal (n=1) at 50% concentration. This concentration was selected as maximum concentration for the main study.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Local Lymph Node Assay (LLNA) - individual animal approach
- Criteria used to consider a positive response (DSD/CLP): Stimulation Index (SI) >3

TREATMENT PREPARATION AND ADMINISTRATION:
Test substance formulation (w/w) were prepared within 4 hours prior to each treatment. Homogeneity was obtained to visually acceptable levels. Formulation was applied to the dorsal ears on three consecutive days.
Positive control substance(s):
hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:
Calculated SI values for 5%, 10% and 25% hexyl cinnamic aldehyde were 1.4, 1.2 and 5.1, respectively. An EC3 value of 16.9% was calculated using linear interpolation. This proves the reliability of the model, as the EC3 value is within the acceptable range of 2% and 20%.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: - 10%: 1.3 - 25%: 2.0 - 50%: 1.6
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: - 0%: 322 - 10%: 425 - 25%: 650 - 50%: 512

Any other information on results incl. tables

- No mortality and no symptoms of systemic toxicity were observed

- Slight irritation observed in the animals of the 50% concentration group

- No effect on body weight (gain)

- All auricular lymph nodes considered normal in size

- No macroscopic abnormalities of area surrounding lymph nodes

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Under the conditions of this study, a maximum Stimulation Index (SI) of 2.0 was calculated. Considering the SI threshold value of 3 as stated in Annex I of 1272/2008/EC and Annex VI of 67/548/EEC, the substance does not need to be classified as sensitiser up to concentrations of 50%.
Executive summary:

This Local Lymph Node Assay (OECD 429) was performed to determine the sensitising potential of Phosphorous slag in mice. Four groups of 5 female mice were used and exposed to concentrations of 0%, 10%, 25% and 50% in propylene glycol. Clinical observations and body weights were recorded, irritation was scored and macroscopic examination of the lymph node area was performed. The lymph node proliferation was determined.

The counts per minute measured by scintillation counting were converted to disintegrations per minute and were 322, 425, 650 and 512 dpm for the 0%, 10%, 25% and 50% concentration groups, respectively. This corresponds with a lymph node proliferation of 1.3, 2.0 and 1.6 for the treated groups, calculated as the Stimulation Index (SI). No mortality and no symptoms of systemic toxicity were observed. Slight irritation was noted in the animals of the 50% concentration group. No effects on body weight (gain) were observed. All auricular lymph nodes considered normal in size and no macroscopic abnormalities of area surrounding lymph nodes were seen.

Under the conditions of this study, a maximum Stimulation Index (SI) of 2.0 was calculated. Considering the SI threshold value of 3 as stated in Annex I of 1272/2008/EC and Annex VI of 67/548/EEC, the substance does not need to be classified as sensitiser up to concentrations of 50%.