2-ethylhexanoic acid, cerium salt

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 4 February 1991 until 18 February 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well documented study performed according to Code of Federal Regulations 16:1500.3 and equivalent to OECD Guideline 401.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: Code of Federal Regulations 16:1500.3

Deviations:

not specified

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Deviations:

no

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cerium chloride hydrate

IUPAC Name:

Cerium chloride hydrate

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Davidson's Mill Farm, S. Brunswick, NJ
- Age at study initiation: no data
- Weight at study initiation: males body weight range: 217 - 228 g; females body weight range: 206-221 g
- Fasting period before study: Rats were fasted on the day before dosing for approximately 18 hours by removing feed from their cages. During fasting, water was provided ad-libitum. After the 18 hour fast period, the rats were examined and weighed again.
- Housing: Individually in suspended stainless steel caging with mesh floors.
- Diet (e.g. ad libitum): Pelleted Purina Rat Chow ad-libitum
- Water (e.g. ad libitum): Tap water supplied by automatic water system
- Acclimation period: 6, 12 or 13 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18.9 °C - 22.8°C
- Humidity (%): No data
- Air changes (per hr): No data

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 50% w/w solution in distilled water
- Amount of vehicle (if gavage): 10 g

Doses:

The dose levels were 2500 and 3500 mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The rats were observed at 1, 2 and 4 hours after dosing and at least once daily thereafter for signs of gross toxicity and mortality. Body weights were recorded initially and at termination (day 14) or after death.
- Necropsy of survivors performed: yes, all survivors to termination were euthanized by CO2 inhalation. Gross necropsies were performed on all decedents.

Statistics:

LD50 calculated by the Litchfield-Wilcoxon Method of Probit Analysis; J. Pharmacology and Experimental Therapeutics 96: 99-115 (1949)

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

2 800 mg/kg bw

Based on:

test mat.

95% CL:

2 360 - 3 320

Mortality:

Dosage 2500 mg/kg: 30% mortality occurred by day 2.
Dosage 3500 mg/kg: 90% mortality occurred by day 3.

Clinical signs:

other: Dosage 2500 mg/kg: Following test material administration all animals appeared lethargic. Most had a hunched posture and two had ano-genital staining. All surviving animals recovered from the above symptoms by day 6 and gained weight over the 14-day obser

Gross pathology:

Dosage 2500 mg/kg: Necropsy of the decedents revealed distention of the stomach with reddish-white discoloration of the pyloric region, discoloration of the intestines and dark-colored fluid in the bladder.
Dosage 3500 mg/kg: Necropsy of the decedents revealed distention of the stomach with discoloration of the pyloric region in most animals. Discoloration of the intestines and dark-colored fluid in the bladder was also noted in most animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The acute oral, single dose LD50 calculated by Probit Analysis was 2800 mg cerium trichloride per kilogram body weight with 95% confidence limits of 2360 and 3320 mg/kg. Based on the criteria of the CLP Regulation, the substance should not be classified for acute oral toxicity as the LD50 value is > 2000 mg/kg.