Disodium 2-hydroxyethyliminodi(acetate)

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1971

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Meets generally accepted scientific standards, well documented and acceptable for assessment (pre-OECD /pre-GLP study)

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1971

Report date:

1971

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Rats were exposed for 4 hours to Na3NTA (different concentration).
Animals were observed 14 days after treatment for clinical signs.
Body weight was measured 15 days after treatment and compared to control animals.

GLP compliance:

no

Remarks:

pre-GLP study

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Trisodium nitrilotriacetate

EC Number:

225-768-6

EC Name:

Trisodium nitrilotriacetate

Cas Number:

5064-31-3

Molecular formula:

C6H9NO6.3Na

IUPAC Name:

trisodium 2,2',2''-nitrilotriacetate

Details on test material:

- Substance type: pure substance
- Physical state: solid, finely divided powder, pale yellow in colour
- Analytical purity: no data

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Test animals: Sprague Dawley albino rats
- Source: no data
- Weight at study initiation: 225-271 g

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

not specified

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure chamber volume: 38 liter glass inhalation chamber
- Method of holding animals in test chamber: no data
- System of generating particulates/aerosols: cyclone dust generator or pulse-puff aerosol generator
- Method of particle size determination: Monsanto Cascade Impactor


TEST ATMOSPHERE
- Brief description of analytical method used: gravimetrical determination of test material concentrations.
- Samples taken from breathing zone: yes, samples of the chamber atmosphere were passed through MSA (Mine safety appliances) glass fiber filters. These filters were subsequently weighed, and the chamber concentration was determined by dividing the total weight of the test material collected on the filter by the volume of air sampled.


TEST ATMOSPHERE (if not tabulated)
Na3NTA (non-micronized) 70 % of the particles smaller that 10 µm, mass median diameter: 6.9 µm.
Na3NTA (micronized) 90 % of the particles smaller that 10 µm, mass median diameter: 4.3 µm.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gravimetrical measurment

Duration of exposure:

ca. 4 h

Concentrations:

3.30, 3.60 and 5.02 mg/l non-micronised NTA
5.033 mg/l micronised NTA

No. of animals per sex per dose:

10 male albino rats per dose

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes
- Other examinations performed:
- Clinical observation, during exposure and during post exposure period, salivation, slow labored respiration, partially closed eyes, hypoactivity
- Body weight, recorded on days 1, 2, 8, 15
- Gross findings
- No histopathology

Statistics:

No details described in the study

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LC0

Effect level:

5 mg/L air

Remarks on result:

other: no deaths at 5.0 mg XTW-448 / l air

Mortality:

No mortalities in rats exposed to any of the above mentioned aerosol concentrations neither non-micronized nor micronized
No effect level could be determined up to 5 mg/l air Na3NTA.

Clinical signs:

other: Group 1 (3.30 mg/l) During the exposure, all rats cleaned themselves in the initial phases. Subsequently, during the first hour of exposure and throughout the remainder of the four hours, the rats exhibited salivation, slow labored respiration, gasping, p

Body weight:

In every instance, rats exposed to non-micronized Na3NTA lost weight after the first exposure, but had recorded an average weight increase by Days 8 and 15. Those rats exposed to micronized Na3NTA recorded a substantial average weight gain by Day 15. For details see table 1.

Gross pathology:

Necropsy findings: No consistent gross alterations were seen in any of the groups of rats exposed to Na3NTA at varying atmospheric concentrations for a period of four hours.
Generally, all tissues appeared normal when compared to those tissues from the control animals.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Single acute Inhalation exposures of male albino rats to various levels of Na3NTA for four hours did not result in mortalities.
The highest concentration (5 mg/l air) was the maximum level attainable under dynamic exposure conditions utilizing a cyclone dust generator or a pulse-puff generator.
There was no difference in the toxicity of the non-micronized or micronized test material.

Clinical observations of rats exposed to various concentrations of the test material generally included salivation, slow labored respiration, partially
closed eyes and hypoactivity. All animals recovered after the exposures, and appeared normal and healthy during the two-week observation period.

Necropsies of rats from each of the exposure groups did not reveal abnormalities which were grossly different from the control group.

Executive summary:

In an acute inhalation toxicity study groups of 10 male Sprague Dawley albino rats per dose were exposed by inhalation route to Na3NTA for 4 hours at concentrations of 3.3, 3.6, 5.0 mg/l (non-micronised NTA) and 5.0 mg/l (micronised NTA). Animals then were observed for 14 days.

No mortality was observed.

Clinical observations disappered within the observation period of 14 days after treatment.

Body weights were normal compared to the control on day 15 after treatment.

Necropsies revealed no differences to control.

The 4-h LC50-value was greater than the highest measured concentration of 5.0 mg Na3NTA/l air.