Registration Dossier

Administrative data

Endpoint:
acute toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 2015-07-01 to 2015-10-19
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2015
Report Date:
2015

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 402 (Acute Dermal Toxicity)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method B.3 (Acute Toxicity (Dermal))
Deviations:
no
GLP compliance:
yes (incl. certificate)
Test type:
standard acute method
Limit test:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
- Name of test material: yttrium trinitrate hexahydrate
- Molecular formula: Y(NO3)3.6H2O
- Molecular weight: 383.01 g/mol
- Appearance: powder
- Storage condition of test material: room temperature (20 ± 5°C) in the dark under dry conditions
- Further information on test material confidential.

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: 5 male and 5 female (nulliparous and non-pregnant) rats, Hsd: Sprague Dawley SD; from Harlan Italy s.r.l. San Pietro al Natisone (UD), Italy
- Age at order: 6 to 8 weeks
- Weight at arrival: 173-183 grams
- Fasting period before study: no data
- Housing: Up to 5 animals of one sex per cage during acclimatisation, individually caged during the study; polysulphone solid bottomed cages measuring 59.5x38x20 cm during acclimatisation period and 42.5x26.6x18.5 cm during the study with nesting material provided into suitable bedding bags; daily inspected and changed as necessary (at least 3 times/week).
- Diet (e.g. ad libitum): ad libitum, 4 RF 18 (Mucedola S.r.l., Via G. Galilei, 4, 20019, Settimo Milanese (MI) Italy)
- Water (e.g. ad libitum): ad libitum, drinking water supplied to each cage via a water bottle
- Acclimation period: at least 5 days, veterinary health check during acclimatisation period

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C +/- 2°C
- Humidity (%): 55 % +/- 15%
- Air changes (per hr): approximately 15-20 per hour
- Photoperiod (hrs dark / hrs light): daily light/dark cycle of 12/12 hours, artificial lighting (fluorescent tubes)

Administration / exposure

Type of coverage:
semiocclusive
Vehicle:
corn oil
Details on dermal exposure:
TEST SITE
- Area of exposure: dorsal surfaces of the trunk of each animal, clipped free of hair on the day before dosing
- % coverage: approximately 10% of the body surface
- Type of wrap if used: A patch of surgical gauze covered by a strip of synthetic film was placed over the treated site and the whole assembly held in place by encircling the trunk of the animal with a lenght of elastic adhesive bandage, this forming a semi-occlusive barrier.

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The treatment area was cleaned by gentle swabbing of the skin with cotton wool soaked with lukewarm water.
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg
- Concentration (if solution): no data
- Constant volume or concentration used: yes
- On the day of dosing, aliquots of the test item to be administered were weighed according to the body weight of each animal measured prior to dosing.

VEHICLE
- Amount(s) applied (volume or weight with unit): 0.5 mL
- Concentration (if solution): no data
- Lot/batch no. (if required): no data
- Purity: no data
Duration of exposure:
24 hours
Doses:
2000 mg/kg
No. of animals per sex per dose:
5
Control animals:
no
Details on study design:
- Duration of observation period following administration: 15 days
- Frequency of observations and weighing:
*mortality and morbidity: throughout the study, all animals were checked twice daily
*clinical signs: Day of dosing: Session 1: on dosing; Session 2: approximately 1 hour after dosing; Session 3: approximately 2 hours after dosing; Session 4: approximately 4 hours after dosing. Daily thereafter for a total of 14 days (Session 1).
*body weight: All animals were weighed at allocation to the study, on the day of dosing (day 1) and on days 8 and 15. Body weight change calculated for days 8 and 15 of the dosing phase was relevant to day 1 of the phase.
- Necropsy of survivors performed: Yes, all animals were sacrificed on day 15 by carbon dioxide narcosis.
- Necropsy was carried out on all animals (gross necropsy examination for both external and internal abnormalities, with particular attention to the treatment site). All abnormalities were recorded.
Statistics:
No data

Results and discussion

Effect levels
Key result
Sex:
male/female
Dose descriptor:
LD50
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Mortality:
No mortality occurred.
Clinical signs:
Clinical signs were limited to scabs on the dorsal/thoracic region observed in male and female animals from day 5 up to day 13/14 of the observation period. In addition, desquamation of the dorsal region was observed in three females on day 7 and in one female only from day 9 to the end of the study.
Body weight:
Body weights and body weight changes were within the expected range for this species and age of animals at the end of the study.
Gross pathology:
No abnormalities were found at the external examination performed in all animals at the end of the study, with the exception of multiple scabs observed on the treatment site of one female (animal no. A1463003). No internal abnormalities were found in any treated animal.

Applicant's summary and conclusion

Interpretation of results:
not classified
Conclusions:
The results indicated that the test item, yttrium trinitrate, has no toxic effect on the rat following dermal exposure over a 24 hour period at a level of 2000 mg/kg (corrected for water content, 28.7%). The lack of mortality demonstrates the acute toxicity expected (ATE) to be greater than 2000 mg/kg. European Directives concerning the classification, packaging and labelling of dangerous substances (Council Regulation (EC) No. 1272/2008 and subsequent revisions) would suggest that the substance is not to be classified.