N,N-bis(carboxymethyl)glycine, compound with 2-aminoethanol (1:3)

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 November 2018 - 11 January 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

yes

Remarks:

see 'Principles of method if other than guideline'

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 bis (Acute Oral Toxicity - Fixed Dose Procedure)

Deviations:

yes

Remarks:

see 'Principles of method if other than guideline'

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.1100 (Acute Oral Toxicity)

Deviations:

yes

Remarks:

see 'Principles of method if other than guideline'

Principles of method if other than guideline:

The following deviations from study plan occurred:
Due to a typographical error, the Study Plan states that the animals would be housed in polypropylene cages; however, the animals were housed in polycarbonate cages.
On each day of dosing, additional clinical observations were recorded that were not specified in the Study Plan.
These deviations were considered to have not affected the integrity or validity of the study.

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

N,N-bis(carboxymethyl)glycine, compound with 2-aminoethanol (1:3)

EC Number:

302-766-4

EC Name:

N,N-bis(carboxymethyl)glycine, compound with 2-aminoethanol (1:3)

Cas Number:

94134-01-7

Molecular formula:

C6H9NO6.3C2H7NO

IUPAC Name:

2-[bis(carboxymethyl)amino]acetic acid; tris(2-aminoethan-1-ol)

Test material form:

solid: bulk

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Envigo RMS (UK) Ltd.
- Females (if applicable) nulliparous and non-pregnant: yes
- Age at study initiation: approximately 8-12 weeks
- Weight at study initiation: range from 153 to 177g
- Fasting period before study: overnight and four hours prior to and after dosing
- Housing: limited access rodent facility in solid bottomed polycarbonate cages with a stainless steel mesh lid.
- Diet (e.g. ad libitum): free access to a standard rodent diet (Teklad 2014C Diet), except for the above mentioned fasting period
- Water (e.g. ad libitum): Potable-water freely available
- Acclimation period: Minimum: five days before treatment

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 40-70
- Air changes (per hr): Periodic checks made
- Photoperiod (hrs dark / hrs light): 12 hrs light/12hrs dark

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 30 and 200 mg/mL
- Amount of vehicle (if gavage):10 mL/kg body weight
- Justification for choice of vehicle:none
- Purity: determination not undertaken as part of this study

Doses:

300 and 2000 mg/kg bw

No. of animals per sex per dose:

5 animals/dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: All surviving animals were observed for 14 days after dosing.
- Frequency of observations and weighing:observed after dosing and at frequent intervals at least 0.5, 1, 2 and 4 hours after dosing) on Day 1. The weight of each rat was recorded on Days 1, 8 and 15 or at death.
- Necropsy of survivors performed: yes
- Other examinations performed: Macroscopic Pathology, Body weight

Results and discussion

Preliminary study:

In the absence of data regarding the toxicity of the test item, 300 mg/kg was chosen as the starting dose.

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 300 - < 2 000 mg/kg bw

Based on:

test mat.

Mortality:

In the main study the rats deaths occured between 40 minutes and 5 hours for rats administered with a dose of 2000 mg/kg.

Clinical signs:

other: Clinical signs prior to death were underactivity, both eyelids partially closed, convulsions, fast breathing, tremors and reduced body temperature in both animals. Flat posture was also seen.

Gross pathology:

No abnormalities were noted in any surviving animal at the macroscopic examination at study termination on Day 15.

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

The acute oral toxicity of N, N’- bis(carboxymethyl)glycine, compound with 2-aminoethanol (1:3) was evaluated. It was concluded that the LD50 of the substance was between 300 and 2,000 mg/kg bw. The substance meets the criteria for classification as Acute Tox 4; H302 according to Regulation 1272/2008.

Executive summary:

An experiment was performed to assess the acute oral toxicity of N, N’- bis(carboxymethyl)glycine, compound with 2-aminoethanol (1:3), in accordance with the OECD Testing Guideline 420. The study was GLP-compliant.

Fasted female rats received a single oral gavage dose of the test item, formulated in purified water. Sighting investigations found no morbidities at 300 and 2000 mg/kg, based on these results a further four fasted females were dosed at 2000 mg/kg in the main study. Due to the number of deaths in the main study at 2000 mg/kg body weight, a further four fasted females were similarly dosed at 300 mg/kg body weight to complete the study. During the study, clinical condition, body weight and macropathology investigations were undertaken. 

Two female animals treated at 2,000 mg/kg bw died as a result of the exposure to the test substance. Clinical signs at this dose level included underactivity, chin rubbing, unsteady gait, repetitive movements, tremors and both eyelids partially closed.

At 300 mg/kg bw, there was no death and no clinical signs were observed.

In accordance with the flow chart associated to the OECD TG 420, the LD50 of N,N’-bis(carboxymethyl)glycine, compound with 2-aminoethanol (1:3) shall be considered as to be between 300 and 2,000 mg/kg body weight.

Therefore the substance meets the criteria for classification as Acute Tox 4; H302 according to Regulation 1272/2008.