Triethoxy(methyl)silane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 3 Sept to 17 Sept 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

the determination of the particle size failed, presumably because the substance was emitted mainly as vapour

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

It was technically not possible to determine the particle size, necropsy was performed but a detailed description of its extend is missing.

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Triethoxy(methyl)silane

EC Number:

217-983-9

EC Name:

Triethoxy(methyl)silane

Cas Number:

2031-67-6

Molecular formula:

C7H18O3Si

IUPAC Name:

triethoxy(methyl)silane

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Hoechst AG, SPF-Zucht, GERMANY
- Age at study initiation: 8-10 wk
- Weight at study initiation: males 188 (184-191) g; females 190 (185-200) g
- Housing: 1/plastic cage
- Diet: standard diet ad libitum
- Water: drinking water ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2
- Humidity (%): 50 +/- 20
- Photoperiod (hrs dark / hrs light): 12h/ 12 h

IN-LIFE DATES: From: 1991-09-03 To: 1991-09-17

Administration / exposure

Route of administration:

other: aerosol/vapour

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
[from report in German]
- Exposure apparatus: cylindrical plastic cages housed in stainless steel inhalation chamber
- Exposure chamber volume: total volume 60 L
- Method of holding animals in test chamber: rats were fitted into test tubes with a coned end reaching into the test chamber
- Source and rate of air: 800 L/h
- Method of conditioning air: air was led at a constant pressure of 4 bar into a nozzle and through separators and filters
- System of generating particulates/aerosols: test substance was injected contineously into the air flow in the nozzle, primary aerosol built in a four-necked round-bottom flask, through a riser-pipe secondary arosol (smaller particle size) reached the test chamber
- Method of particle size determination: The determination of the particle size was not possible as teh substance was mainly emitted as gas.

TEST ATMOSPHERE
- Brief description of analytical method used: gas chromatography with FID detector
- Samples taken from breathing zone: yes


TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: not given
- MMAD (Mass median aerodynamic diameter) / GSD (Geometric st. dev.): not given

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

13.5 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: observations 2/day; weights on Days 0, 7 and 14
- Necropsy of survivors performed: yes
- Other examinations performed: no other examinations

Statistics:

Single exposure concentration - no statistics presented.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 13 500 mg/m³ air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Taking into account that the measured concentration (13.5 mg/L) greatly exceeds the saturated vapour concentration (7.19 mg/L), the exposure atmosphere is considered a mixture of saturated vapour and aerosol.

Mortality:

1/5 males; 0/5 females

Clinical signs:

other: Ataxia, irregular respiration, stupor, altered gait, prostration, tonic convulsions, trembling and reduced spontaneous activity were seen in both sexes during the 14-day observation period.

Body weight:

No treatment-related effect identified.

Gross pathology:

1/5 males had dark red, patchy lungs. [The extent of examination is unclear.]

Any other information on results incl. tables

Table 1: Concentration and mortality per animals treated

Analytical Conc. (mg/L)	Mortality (dead/total)
	Males	Females	Combined
13.5	1/5	0/5	1/10

Applicant's summary and conclusion

Interpretation of results:

other: CLP/EU GHS criteria are not met, no classification required according to Regulations (EC) No 1272/2008

Conclusions:

In an acute inhalation (vapour) study conducted in compliance with OECD 403 and GLP (reliability score 1) in which rats were exposed to triethoxy(methyl)silane at a concentration of 13.5 mg/L for four hours only one animal from a total of ten died. The LC50 thus is greater than 13.5 mg/L (highest achievable dose).