Disodium 2-hydroxyethyliminodi(acetate)

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From Jan 21 1986 to Feb. 4, 1986

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study meets basic scientific principles/standards, non GLP study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 401 (Acute Oral Toxicity)

Principles of method if other than guideline:

Acute oral toxicity or LD50 value was determined by administration of test substance to 5 groups of animals (5 rats/sex/group). Subsequently, observations of effects such as mortality, body weight and clinical signs were made for 14 days. A gross necropsy was performed on the day of death or after terminal sacrifice on all animals.

GLP compliance:

no

Remarks:

in house QA audited

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-hydroxyethyliminodi(acetic acid)

EC Number:

202-263-9

EC Name:

2-hydroxyethyliminodi(acetic acid)

Cas Number:

93-62-9

Molecular formula:

C6H11NO5

IUPAC Name:

2,2'-[(2-hydroxyethyl)imino]diacetic acid

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material : Hydroxyethyliminodiacetic acid (HEIDA)
- TSIN- E-2748.01
- Substance type: Pure active substance
- Physical state: White powder
- Stability under test conditions: Not reported- Storage condition of test material: Ambient temperature

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Charles River UK, Limited
- Age at study initiation: 4-6 weeks
- Weight at study initiation: 194-220 g
- Fasting period before study: Access to food was prevented overnight prior to dosing and approximately 4 hours after dosing
- Housing: Housed in groups by sex in metal cages with wire mesh floors
- Diet : Standard laboratory rodent diet (Labgure LAD 1), ad libitum
- Water: ad libitum
- Acclimation period: Minimum 6 days

ENVIRONMENTAL CONDITIONS
- Temperature: 20-22 °C
- Humidity: 60% (mean)
- Air changes: 15 air changes /h
- Photoperiod : 12/12 hrs dark / hrs light

EXPERIMENT INITITATION DATE: Jan 21 1986

EXPERIMENT COMPLETION DATE: Feb. 4, 1986

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 15 % w/v in distilled water
- Amount of vehicle (if gavage): 18.3 mL/kg
MAXIMUM DOSE VOLUME APPLIED: 18.3 mL/Kg

Doses:

0, 1000, 1400, 1960, 2740 mg/kg bw

No. of animals per sex per dose:

5 animals/sex/dose

Control animals:

yes

Details on study design:

PRELIMINARY STUDY: A preliminary study was conducted with 2 males and 2 females rats at three dose levels of 1000, 1400 and 1960 mg/kg bw. The results indicated that the acute median lethal oral dose was between 1400 and 1960 mg/kg bw. Based on the preliminary study, further groups of rats were dosed in order to locate the LD50 more precisely.

MAIN STUDY
- Treatment procedure: The test solution was mixed immediately prior to dosing using a magnetic stirrer. The appropriate dose volume of the test substance was administered to each rat using a syringe and plastic catheter.
- Duration of observation period following administration: 14 days (Animals of preliminary study were observed for 5 days)
- Frequency of observations and weighing: Animals were observed soon after dosing, then at frequent intervals for the remainder of Day 1, on subsequent days the animals were observed at least twice per day. Body weights were observed at Day1, 8,15 and at death.
- Necropsy of survivors performed: Yes, surviving animals were killed on Day 15 by CO2 asphyxiation. All animals that died during the study and those killed on Day 15 were subjected to a macroscopic post mortem examination
- Other examinations performed: Clinical signs, body weight, organ weights, organ to body weight ratios, histopathology, mortality

Statistics:

- The acute median lethal oral dose (LD50) to male and female rats was calculated using the method of Finnery (1971) probit analysis (3rd edition) cambridge University Press.
- Separate LD50 values for males and females were estimated by undertaking probit analysis on the mortality data by fitting two parallel lines on the data (males and females only using the technique described by Finnery (1978, Statistical method in Biological Assay, 3rd edition, Charles Griffith, London).
- A chi-squared test was carried out to check that the data did not contain any evidence for non-parallelism.

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LD50

Effect level:

1 600 mg/kg bw

Based on:

act. ingr.

95% CL:

1 400 - 2 000

Effect levels 2

Sex:

male

Dose descriptor:

LD50

Effect level:

1 300 mg/kg bw

Based on:

act. ingr.

95% CL:

1 100 - 1 700

Effect levels 3

Sex:

female

Dose descriptor:

LD50

Effect level:

2 000 mg/kg bw

Based on:

act. ingr.

95% CL:

1 600 - 2 600

Mortality:

Mortality observed at individual dose levels was as follows:
-1000 mg/kg bw: 2/5 male and 0/5 female;
- 1400 mg/kg bw: 1/5 male and 0/5 female;
- 1960 mg/kg bw: 5/5 males and 2/5 females;
- 2740 mg/kg bw: 5/5 males and 5/5 females

Clinical signs:

other: Signs of reaction to treatment observed after dosing in all rats receiving test material were pilo-erection, abnormal body carriage (hunched posture), abnormal gait (wedding) and lethargy. These signs were accompanied by decreased respiratory rate, pallor

Gross pathology:

Macroscopic terminal autopsy findings were normal.

Other findings:

- ORGAN WEIGHTS: Actual kidney weights of surviving male rats treated at 1400 mg/kg bw and females at 1960 mg/kg were slightly higher than the controls. An apparent reduction in liver weight was observed in surviving female rats treated at 1960 mg/kg and one female at 1400 mg/kg. The differences in these parameters between treatment groups and the controls were all low in magnitude and individual values were generally within the normal ranges expected for animals of this age and strain.
- HISTOPATHOLOGY
- Rats dying during the course of the study: Renal lesions were considered to the cause of death in all decedent rats which received 2740 or 1960 mg/kg bw and in one of the two decedent rats which received 1000 mg/kg bw. The primary lesion was marked vacuolation of the cortical tubular epithelium.
- Rats killed at termination: Treatment related histopathological changes of the kidney were observed. Generalized marked vacuolation of the cortical tubular epithelium was seen in 2 rats (one male rat of 1400 mg/kg bw and one male rat of 1000 mg/kg bw dose groups). Minimal groups of basophilic cortical tubules were seen in 6 treated rats (1 rat of 1960 mg/kg bw, 4 rat of 1400 mg/kg bw, 1 rat of 1000 mg/kg bw dose groups) compared to occasional basophilic cortical tubules in 2/10 rats from the control group. Focal tubular vacuolation was seen in one female rat (1960 mg/kg bw dose group).
The kidneys of all other rats killed at termination were considered to be normal.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The acute median lethal oral dose of Hydroxyethyliminodiacetic acid in male and female rats was determined to be 1600 (95% confidence limits: 1400-2000) mg/kg bw.

Executive summary:

The objective of this study was to determine the acute toxicity of Hydroxyethyliminodiacetic acid after oral administration.

Male and female Sprague-Dawley rats, obtained from Charles River UK, Limited, (weighing between 194-220 g) were used in the study. Animals were housed in metal cages with wire mesh floors and supplied with standard laboratory rodent diet, ad libitum. Animals were fasted overnight prior to dosing. Standard laboratory conditions (temperature: 20-22 °C, humidity: 60%, air changes: 15 air changes /h, 12/12 hrs dark / hrs light photoperiod) were maintained during the test.

A preliminary study was conducted with 2 male and 2 female rats at three dose levels of 1000, 1400 and 1960 mg/kg bw. The results indicated that the acute median lethal oral dose was between 1400 and 1960 mg/kg bw. Based on the preliminary study, a main study was conducted in order to determine the LD50 more precisely.

In the main study, 5 animals/sex were treated once orally at dose levels of 0, 1000, 1400, 1960 or 2740 mg/kg bw. Test material was prepared at 15% w/v in distilled water and administered at a volume not exceeding 18.3 mL/kg. Animals were observed for mortality, body weight and clinical signs for up to 14 days. Surviving animals were killed on Day 15 by CO2 asphyxiation. All animals that died during the study and those killed on Day 15 were subjected to a macroscopic post mortem examination.

Mortality observed during the test was as follows:

1000 mg/kg bw: 2/5 male and 0/5 female;

1400 mg/kg bw: 1/5 male and 0/5 female;

1960 mg/kg bw: 5/5 males and 2/5 females;

2740 mg/kg bw: 5/5 males and 5/5 females.

Signs of reaction to treatment observed in all rats receiving test material were pilo-erection, abnormal body carriage (hunched posture), abnormal gait (wedding) and lethargy. These signs were accompanied by decreased respiratory rate, pallor of the extremities, clonic convulsions, increased lacrymation, body tremors, ptonis and diarrhea. Pilo-erection was the only clinical sign observed in control animals. Recovery as judged by external appearance and behavior was apparently complete by Day2 (controls), Day 6 (1000 mg/kg bw), or Day 7 (1400 mg/kg bw and 1960 mg/kg).

Macroscopic terminal autopsy findings were normal.

Actual kidney weights of surviving male rats treated at 1400 mg/kg bw and females at 1960 mg/kg were slightly higher than the controls. An apparent reduction in liver weight was observed in surviving female rats treated at 1960 mg/kg and one female at 1400 mg/kg. The differences in these parameters between treatment groups and the controls were all low in magnitude and individual values were generally within the normal ranges expected for animals of this age and strain.

Renal lesions were considered to the cause of death in all decedent rats which received 2740 or 1960 mg/kg bw and in one of the two decedent rats which received 1000 mg/kg bw. The primary lesion was marked vacuolation of the cortical tubular epithelium.

Treatment related histopathological changes of the kidney were observed in rats sacrificed at termination. Generalized marked vacuolation of the cortical tubular epithelium was seen in 2 rats (one male rat of 1400 mg/kg bw and one male rat of 1000 mg/kg bw dose groups). Minimal groups of basophilic cortical tubules were seen in 6 treated rats (1 rat of 1960 mg/kg bw, 4 rat of 1400 mg/kg bw, 1 rat of 1000 mg/kg bw dose groups) compared to occasional basophilic cortical tubules in 2/10 rats from the control group. Focal tubular vacuolation was seen in one female rat (1960 mg/kg bw). The kidneys of all other rats killed at termination were considered to be normal.

The acute median lethal oral dose of Hydroxyethyliminodiacetic acid in male and female rats was determined to be 1600 (95% confidence limits: 1400-2000) mg/kg bw (LD50 in males: 1300 mg/kg bw; LD50 in females: 2000 mg/kg bw).