Registration Dossier

Toxicological information

Acute Toxicity: oral

Currently viewing:

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From May 21 to Agust 20, 2013
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
Qualifier:
according to
Guideline:
EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)
GLP compliance:
yes (incl. certificate)
Test type:
acute toxic class method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
female
Details on test animals and environmental conditions:
Species and strain: Rat, Crl: CD (SD) Sprague Dawley
Sex: Females (nulliparous and non-pregnant)
Age and weight range: 6 to 7 weeks old, 150 to 174 grams (at order)
Supplier: Charles River Italia S.p.A., Calco (Lecco), Italy
Breeder: Charles River Italia S.p.A., Calco (Lecco), Italy
Date of arrival: 16 May and 18 July 2013
Acclimatisation period: At least 5 days
Veterinary health check: After arrival
No. of animals/cage: 3 during the study; up to 5 during acclimatisation
Housing: Solid bottomed cages measuring 59.5x38x20 cm, with nesting material provided into suitable bedding bags.
Cage control: Daily inspected and changed as necessary (at least 2 times/week)
Water: Drinking water supplied to each cage via a water bottle
Water supply: Ad libitum
Diet: 4 RF 18 (Mucedola S.r.l., Via G. Galilei, 4, 20019, Settimo Milanese (MI) Italy)
Diet supply: Ad libitum throughout the study except for dosing procedure
Room lighting : Artificial (fluorescent tubes), daily light/dark cycle of 12/12 hours
Air changes: Approximately 15 to 20 air changes per hour
Temperature range: 22 °C ± 2 °C
Relative humidity range: 55 % ± 15 %

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
Frequency of treatment: Once only, on the day of dosing (Day 1).
Fasting procedure: Overnight prior to dosing (Day –1) up to 4 hours after dosing.
Dose calculation: Dose volume of 10 ml/kg of body weight for each animal.
Dosing method: By gavage, using a plastic feeding tube attached to a syringe of suitable capacity.
Doses:
300 mg/kg
2000mg/kg
No. of animals per sex per dose:
6 females
Control animals:
no
Details on study design:
A first sub-group of 3 female animals was dosed at a level of 300 mg/kg (Step 1). No mortality occurred. A second sub-group, similarly composed, was then dosed at the same dose level (Step 2). No mortality occurred. On the basis of these results and of the testing strategy indicated in the OECD 423, a further sub-group of 3 females was dosed at a dose level of 2000 mg/kg (Step 3). Mortality did not occur. A further sub-group was finally dosed at the same dose level (2000 mg/kg, Step 4). Two animals died following dosing.
No further doses were investigated since the objective of the study had been achieved.
Statistics:
No statistic analysis necessary.

Results and discussion

Effect levelsopen allclose all
Sex:
female
Dose descriptor:
LD0
Effect level:
ca. 300 mg/kg bw
Based on:
test mat.
Sex:
female
Dose descriptor:
LD50
Effect level:
ca. 2 000 mg/kg bw
Based on:
test mat.
Mortality:
0/3 + 0/3 at 300 mg/kg
0/3 + 2/3 at 2000 mg/kg
Clinical signs:
Piloerection was observed approximately 2 and 4 hours after dosing in the animals initially dosed at 300 mg/kg (Step 1) and in the further 3 females dosed at the same dose level (300 mg/kg - Step 2). Recovery occurred by Day 2.
No mortality occurred in the first three animals initially dosed at 2000 mg/kg (Step 3). Reduced activity and semiclosed eyes were observed on the day of dosing. Reduced activity was still observed on Day 2 in all animals. Semiclosed eyes were observed on Day 2 in one animal only. All animals recovered by Day 3.
Death occurred in two out of three animals of the fourth sub-group subsequently dosed at 2000 mg/kg (Step 4). One animal was found dead 4 hours after dosing, while the second one on Day 3. Reduced activity, piloerection, hunched posture and semiclosed eyes were observed on the day of dosing. Surviving animals showed piloerection and hunched posture the day after dosing (Day 2). In addition, reduced activity, scab on the neck and pallor were observed at the same observation in the animal found dead on Day 3. Recovery occurred in the surviving animal by Day 4.
Body weight:
Changes in body weight observed during the study in the animals dosed at 300 mg/kg were within the expected range for this strain and age of animals.
Body weight losses or reduced body weight gain were noted in the animals treated at 2000 mg/kg on Day 2 of the observation period. Changes in body weight recorded at the end of the observation period in surviving females were within the expected range for this strain and age of animals.
Gross pathology:
The necropsy examination performed at the end of the observation period on all animals dosed at 300 mg/kg (Steps 1 and 2) did not reveal any external or internal alterations.
Necropsy examination performed in the early decedent females treated at 2000 mg/kg (Step 4) revealed red areas in the glandular region of the stomach in both animals. In addition, red colour of the glandular region/mucosa of the stomach, jejunum and caecum and mucoid material in the stomach and jejunum were observed in one of these early decedent females. The necropsy examination performed at the end of the observation period on surviving females dosed at 2000 mg/kg (Steps 3 and 4) did not reveal any external or internal alterations.

Applicant's summary and conclusion

Interpretation of results:
other: Category 4 (Harmful if swallowed) based on CLP Regulation (EC no. 1272/2008)
Conclusions:
The acute toxicity of Ca(H2PO2)2 was investigated following a single oral administration (10 ml/kg in purified water) to the Sprague Dawley rat followed by a 14-day observation period.
No mortality occurred and no significant clinical signs were observed in the 6 animals following dosing at 300 mg/kg.
Mortality occurred in 2/6 animals dosed at 2000 mg/kg within Day 3 of the study. Several clinical signs were observed after dose of 2000 mg/kg.
These results indicate that the test item Ca(H2PO2)2 induced effects of toxicological relevance (mortality) in the rat following oral administration of a single dose at 2000 mg/kg. No mortality or severe signs of toxicity were observed following dosing at 300 mg/kg. These results indicate the LD50 to be greater than 300 but lower than 2000 mg/kg body weight.

European Directives concerning the classification, packaging and labelling of dangerous substances (Council Regulation (EC) No. 1272/2008 and subsequent revisions) would indicate the following:

Classification : Category 4
Signal word : Warning
Hazard statement H302: Harmful if swallowed

Executive summary:

The acute toxicity of Ca(H2PO2)2 was investigated following a single oral administration to the Sprague Dawley rat followed by a 14-day observation period.

A first sub-group of 3 female animals was initially dosed at 300 mg/kg (Step 1). No mortality occurred. Clinical signs were limited to piloerection, observed on the day of dosing.

A second sub-group of 3 female animals was then dosed at the same dose level (Step 2). No deaths occurred. Piloerection was observed on the day of dosing.

A third sub-group was dosed at a higher dose level of 2000 mg/kg (Step 3). No deaths occurred. Clinical signs observed were reduced activity and semiclosed eyes. Recovery occurred by Day 3.

A fourth sub-group was finally dosed at 2000 mg/kg (Step 4). Two animals were found dead on Days 1 and 3 of the observation period. The following signs were noted after dosing: reduced activity, piloerection, hunched posture, semiclosed eyes, pallor and scab on the neck. Recovery occurred in the surviving animal by Day 4.

 

Body weight changes recorded during the observation period in the animals treated at 300 mg/kg were within the expected range for this strain and age of animals.

Body weight losses/reduced body weight gain were observed in the animals treated at 2000 mg/kg on Day 2 of the observation period. Changes in body weight observed at the end of the observation period in surviving females were within the expected range for this strain and age of animals.

No abnormalities were observed at necropsy examination performed on animals treated at 300 mg/kg at the end of the observation period.

Necropsy examination performed in the early decedent females treated at 2000 mg/kg revealed abnormal areas in the stomach of both animals. In addition, abnormal red colour of the stomach, jejunum and caecum and mucoid material in the stomach and jejunum were observed in one of these early decedent females. The necropsy examination performed at the end of the observation period on surviving females dosed at 2000 mg/kg did not reveal any external or internal alterations.

These results indicate that the test item Ca(H2PO2)2 induced effects of toxicological relevance (mortality) in the rat following oral administration of a single dose at 2000 mg/kg. No mortality or severe signs of toxicity were observed following dosing at 300 mg/kg. These results indicate the LD50 to be greater than 300 but lower than 2000 mg/kg body weight.

European Directives concerning the classification, packaging and labelling of dangerous substances (Council Regulation (EC) No. 1272/2008 and subsequent revisions) would indicate the following:

Classification: Category 4

Signal word: Warning

Hazard statement: H302: Harmful if swallowed