Germanium

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

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 1

Reference Type:

publication

Title:

Acute and sub-acute inhalation toxicity of germanium metal powder in rats

Author:

Arts JHE, Reuzel PGJ, Falke HE and Beems RB

Year:

1990

Bibliographic source:

Food Chem Toxicol. Vol. 28, No. 8, pp. 571-579

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes (incl. QA statement)

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Germanium

EC Number:

231-164-3

EC Name:

Germanium

Cas Number:

7440-56-4

Molecular formula:

Ge

IUPAC Name:

germanium

Test material form:

solid: particulate/powder

Details on test material:

Name of test material (as cited in study report): germanium powder
- Physical state: grey powder
- Analytical purity: 99.8%

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: SPF-reared, Wistar derived rats (strain code Bor:WISW) delivered by Winkelmann, Versuchstierzucht GmbH & Co KG, Borchen, FRG
- Age at study initiation: no information
- Weight at study initiation: mean body weight: M: 272g, F: 198g
- Housing: individually in wire-mesh stainless steel cages
- Diet : cereal based Institute's stock diet ad libitum
- Water : bottled tap water ad libitum
- Acclimation period: acclimatized for at least 16 days in a cleaned and desinfected animal room in the inhalation facilities

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.3 ± 0.90C
- Humidity (%): between 29 and 46 (average 37)
- Air changes (per hr): 30 to 44
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

whole body

Vehicle:

not specified

Mass median aerodynamic diameter (MMAD):

ca. 2.3 - ca. 2.5 µm

Geometric standard deviation (GSD):

ca. 1.4 - ca. 1.5

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION:
Before the generation of the test atmosphere, the test material was dried in an oven (settings 2.5 hours, 15O0C). Thereafter the test material was ground using a blender. An aerosol was generated by delivering appropriate quantities of the test material to an atomizer. Next the aerosol was passed through a cyclone placed close to the bottom of the chamber for separating the larger particles from the aerosol. The aerosol was subsequently diluted with clean air before entering the inhalation chamber.
TEST ATMOSPHERE
The actual mass concentration of germanium powder in the test atmosphere was determined at least two times each hour by gravimetry. Measured test atmosphere samples were drawn through fiber glass filters (Sartorius). The weights of the deposits on the filters were obtained by weighing the filters before and after sampling using a micro balance. The nominal concentration was determined by dividing the total amount of test material used by the total volume of air passed through the inhalation chamber. The particle size distribution of the test material in the test atmosphere was determined once in a sample taken from the test atmosphere in the chamber using an 11-stage cascade impactor.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

3.86 g/m3: first group exposed
5.34 g/m3: second group exposed

No. of animals per sex per dose:

per exposed group : 5 rats per sex

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: 3 times (prior to exposure, at days 7 and days 14)
- Necropsy of survivors performed: no
- Other examinations performed: clinical signs, body weight,histopathology

Statistics:

no statistics reported

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 5 340 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

One male animal died shortly after exposure to 3.86 g/m3, one female animal died shortly after exposure to 5.34 g/m3.

Clinical signs:

other: During the first hour of exposure the animals were restless. One male animal exposed to 3.86 g/m3 showed mouth breathing. During the rest of the exposure period observations were impossible due to very high dust concentrations which did not allow any view

Body weight:

One male animal exposed to 5.34 g/m3 showed a slight weight loss seven days after exposure, whereas weight gain was observed at the end of the
14-day observation period. Body weights of the other animals were not affected by exposure.

Gross pathology:

Gross examination at autopsy revealed red spotted lungs in most animals exposed to 3.86 g/m3
In most animals autopsied after exposure to 5.34 g/m3, lungs showed grey-white, occasionally red, coloured spots or were palely discoloured with dark coloured spots.

Other findings:

none

Any other information on results incl. tables

none

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

4 hours LC50 value of germanium powder was higher than 5.34 g/m3

Executive summary:

The acute (4 -hour) inhalation toxicity of germanium powder was studied by exposing total-body group of rats, consisting of five male and five female rats , to a test atmosphere containing germanium powder at a concentration of 3.86 or 5.34 g/m3 in air respectively for one single time for a period of 4 hours.

It was concluded that the 4 hours LC50 value of germanium powder was higher than 5.34 g/m3