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Acute Toxicity: oral

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acute toxicity: oral
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP guideline study Minor deviations without an effect on the study results: - A rationale for choosing the limit dose was not given

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)
see "rationale for reliability"
GLP compliance:
Test type:
up-and-down procedure

Test material

Constituent 1
Chemical structure
Reference substance name:
Calcium dihydroxide
EC Number:
EC Name:
Calcium dihydroxide
Cas Number:
Molecular formula:
calcium dihydroxide
Details on test material:
calcium dihydroxide, as a surrogate material for elemental calcium which does not occur free in nature and as highly reactive can not be tested as such.

- Name of test material (as cited in study report): Precal 50S (Calcium dihydroxide (hydrated lime)
- Physical state: White powder
- Analytical purity: 98.2 %
- Batch No.: 7025
- Expiration date of the batch: January 2009
- Stability of test item: Stable under storage conditions
- Storage condition of test material: At room temperature (range of 22 +/- 5°C), moisture protected
No further information on the test material was stated.

Test animals

Details on test animals or test system and environmental conditions:
- Source: RCC Ltd, Laboratory Animal Services, CH-4414 Füllinsdorf/Switzerland
- Age at study initiation: 11 weeks
- Weight at study initiation: 185.1 to 206.5 g
- Fasting period before study: Approximately 16 to 19 hours; Food was provided again approximately 3 hours after dosing
- Housing: Individually in Makrolon type-3 cages with standard softwood bedding ("Lignocel", Schill AG, CH-4132 Muttenz) during treatment and observations
- Diet (ad libitum): Pelleted standard Provimi Kliba 3433 rat/mouse maintenance diet, batch no. 80/06 or 89/06 (Provimi Kliba AG, CH-4303 Kaiseraugst/Switzerland)
- Water (ad libitum): Community tap water from Füllinsdorf
- Acclimation period: Seven days under laboratory conditions
- Temperature: 22 +/- 3°C
- Humidity: 30-70 %
- Air changes: 10-15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12/12
No further information on the test animals was stated.

Administration / exposure

Route of administration:
oral: gavage
polyethylene glycol
Details on oral exposure:
VEHICLE: Polyethylene glycol 300 (PEG 300)
- Description: Colourless viscous liquid
- Source: FLUKA Chemie GmbH, CH-9471 Buchs
- Stability of vehicle: Stable under storage conditions
- Expiration date: October 2007
- Storage conditions: At room temperature (range of 20 +/- 5°C), light protected
- Justification for choice of vehicle: The vehicle was chosen after a non-GLP solubility trial which was performed before the study initiation date. Polyethylene glycol 300 was the most suitable vehicle selected
for the test item.
- Lot no.: 1300225

- Concentration in vehicle: 0.2 g/mL
MAXIMUM DOSE VOLUME APPLIED: The application volume was 10 mL/kg body weight.
The dose formulations were made shortly (i.e. less than 30 minutes) before each dosing occasion using a magnetic stirrer and a spatula. The test item was weighed into tared glass beaker on a suitable
precision balance and the vehicle added (weight:volume). The pH of the freshly prepared dose formulations was mesaured at each occasion following preparation and was found to be between pH 6-7 for the
test item. Temperature of the freshly prepared dose formulations were generally between 20-23 °C. Homogeneity of the test item in the vehicle was maintained during administration using a magnetic stirrer.
The stability of the test item in the vehicle was not determined in this test. This is not considerd to be required because of the short period between dose preparation and administration to the animals.
No further information on oral exposure was stated.
2000 mg/kg body weight
No. of animals per sex per dose:
5 female rats
Control animals:
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Observations of mortality/viability was made daily during the acclimatization period, during the first 30 minutes and at approximately 1, 2, 3 and 5 hours after
administration on the day of dosing (test day 1; with the clinical signs) and twice daily during days 2 - 15. Observations of body weight were made on the day prior to the administration of the test item, on the
day of administration of the test item (prior to administration of the test item), and on days 8 and 15. Observations on clinical signs were made daily during the acclimatization period, during the first 30
minutes and at approximately 1, 2, 3 and 5 hours after the administration on test day 1. Once daily during days 2-15.
- Necropsy of survivors performed: Yes
All animals were killed by carbon dioxide asphyxiation and discarded after macroscopic examinations have been performed.
- Other examinations performed: For clinical signs all abnormalities were recorded.
No further information on the study design was stated
No statistical analysis was performed.

Results and discussion

Effect levels
Dose descriptor:
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Remarks on result:
other: nominal effext, any adverse effect were not seen
No deaths occured during the study.
Clinical signs:
other: Slightly ruffled fur was noted at the 30-minutes reading up to day 2, 4, 5 or 7 in four animals. Hunched posture was observed at the 30-minutes reading up to the 1-, 3- or 5-hour reading in these animals. Slightly to moderately ruffled fur at the 30-minut
Gross pathology:
No macroscopic findings were observed at necropsy.

Applicant's summary and conclusion

Interpretation of results:
not classified
Migrated information Criteria used for interpretation of results: EU
Acute oral toxicity of calcium dihydroxide is presented for calcium to demonstrate the non-toxicity of calcium and its reaction products with air and water. Elemental calcium does not occur free in nature and due to its highly reactive nature it can not be tested for acute oral toxicity.

The median lethal dose for the test item Precal 50S (Calcium dihydroxide (hydrated lime)) after single oral administration to female rats, observed over a period of 14 days is: LD50 (rat): greater than 2000
mg/kg body weight.
According to the criteria specified by Directive 67/548/EEC and subsequent regulations, the test item is not classified.
According to the EC Regulation No. 1272/2008 and subsequent regulations, the test item is not classified.