Ammonium hydrogencarbonate

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Data taken from EU risk assessment/SIDS; Guideline study

Data source

Reference

Reference 1

Reference Type:

publication

Title:

SIDS Initial Assessment Report For SIAM 15

Author:

OECD

Year:

2003

Bibliographic source:

SIDS Dossier Sodium Bicarbonate, Final July 2003

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OTS 798.1150 (Acute inhalation toxicity)

Deviations:

no

GLP compliance:

yes

Remarks:

Product Safety Labs, New Jersey, USA

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Sodium hydrogencarbonate

EC Number:

205-633-8

EC Name:

Sodium hydrogencarbonate

Cas Number:

144-55-8

IUPAC Name:

sodium hydrogen carbonate

Details on test material:

- Name of test material (as cited in study report): sodium bicarbonate
- Analytical purity: > 99.5%

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hilltop Lab Animals, Scottdale, PA.
- Age at study initiation: the report states that the rats were young adults, but the exact age is not given
- Weight at study initiation: 224 - 239 g (males), 219 - 226 g (females)

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

not specified

Vehicle:

other: no data

Details on inhalation exposure:

TEST ATMOSPHERE
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): in two samplings of two minutes duration 2.9 +/- 1.77 µm and 2.7 +/- 2.04 µm, respectively.

PREPARATION OF PARTICLE:
The test substance was ground for 24 hours in a ball mill prior to aerosolisation. Thereafter it was sieved through a 425 micron screen to separate it from the grinding medium and any other large particles which remained.

Analytical verification of test atmosphere concentrations:

yes

Remarks:

by gravimetric calculation

Duration of exposure:

4.5 h

Concentrations:

4.74 +/- 1.03 mg/l

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: body weight was measured prior to exposure and on days 1, 7 and 14. Animals were observed before exposure commenced, every 15 min during the first exposure hour, and every 15 min thereafter through exposure termination.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 4.74 mg/L air

Exp. duration:

4.5 h

Mortality:

There was no mortality

Clinical signs:

other: During the first hour of exposure, reduced movement and hunched posture were noted for most animals. At exposure termination test substance was observed on the fur of two animals, while the same was observed in all the remaining rats on the one or two aft

Body weight:

All the animals gained body weight during the observation period (body weight males at 14 days: 311 - 341 g; body weight females at 14 days: 254 - 267 g).

Gross pathology:

The general findings at gross necropsy were unremarkable. One male and one female had moderately red lung tissue, while one male had slightly red lung tissue.