Etidronic acid

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

No data

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1965

Report date:

1965

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Version / remarks:

Study conducted prior to the adoption of OECD test guidelines.

Deviations:

yes

Remarks:

Level of report detail does not meet current standards.

GLP compliance:

no

Remarks:

Study was conducted prior to GLP.

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Etidronic acid

EC Number:

220-552-8

EC Name:

Etidronic acid

Cas Number:

2809-21-4

Molecular formula:

C2H8O7P2

IUPAC Name:

(1-hydroxyethane-1,1-diyl)bis(phosphonic acid)

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Not specified
- Females (if applicable) nulliparous and non-pregnant: Not specified
- Age at study initiation: Not specified
- Weight at study initiation: from 225 to 270 g
- Fasting period before study: Not specified
- Housing: Not specified
- Diet (e.g. ad libitum): Not specified
- Water (e.g. ad libitum): Not specified
- Acclimation period: Not specified

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Not specified
- Humidity (%): Not specified
- Air changes (per hr): Not specified
- Photoperiod (hrs dark / hrs light): Not specified

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

not specified

Details on oral exposure:

The test substance was administered by gavage (dosing volumes not stated, as a 50% aqueous solution).   No details about the range-finding study, test conditions or observation schedule are provided.  

Doses:

2000, 2510, 3160 and 3980 mg/kg bw

No. of animals per sex per dose:

3 females and 2 males at 2000 mg/kg bw
3 females and 2 males at 2510 mg/kg bw
2 females and 3 males at 3160 mg/kg bw
2 females and 3 males at 3980 mg/kg bw

Control animals:

no

Details on study design:

- Duration of observation period following administration: Clinical signs of toxicity observed for, but duration not stated.
- Frequency of observations and weighing: No data
- Necropsy of survivors performed: yes
- Other examinations performed: macroscopic examination of the viscera of animals that died.

Statistics:

LD50 calculated by a modification of the method of E.J. de Beer (no further details).  Calculation was not presented in study report.

Results and discussion

Preliminary study:

No data

Effect levels

Sex:

male/female

Dose descriptor:

LD50

Effect level:

3 130 mg/kg bw

Based on:

test mat.

95% CL:

> 2 660 - < 3 665

Remarks on result:

other: presumed equivalent to 1878 mg active acid/kg bw

Mortality:

No death was observed at 2000 mg/kg bw. One female died at 2510 mg/kg bw. Two male and one female rats died at 3160 mg/kg bw. Two male and two female rats died at 3980 mg/kg bw. Survival time was one to eight hours with most deaths occurring in one to two hours.

Clinical signs:

other: Toxic symptoms included weakness followed by dyspnoea and collapse.

Gross pathology:

At autopsy there was inflammation of the gastric mucosa and haemorrhagic areas in the lungs.

Other findings:

No data

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

In a well conducted acute oral study (reliability score 2), conducted using a protocol similar to the now deleted OECD 401, but not to GLP, an LD50 of 3130 mg/kg bw was determined for the test substance (60% HEDP-H) in the rat (reviewer of IUCLID comment: presumed equivalent to 1878 mg active acid/kg bw) .