Trimethoxy(2,4,4-trimethylpentyl)silane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30 Jan - 13 Feb 1986

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Version / remarks:

(1981)

Deviations:

no

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Trimethoxy(2,4,4-trimethylpentyl)silane

EC Number:

251-995-5

EC Name:

Trimethoxy(2,4,4-trimethylpentyl)silane

Cas Number:

34396-03-7

Molecular formula:

C11H26O3Si

IUPAC Name:

trimethoxy(2,4,4-trimethylpentyl)silane

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Strain: Wistar Hoe: WISKf(SPF71)
- Source: HOECHST AG, Kastengrund, Germany
- Age at study initiation: 8-10 weeks
- Weight at study initiation: Males: 207-225 g; Females: 170-181 g.
- Housing: In groups of five animals in Makrolon Type IV cages.
- Diet: Rat diet Altromin 1324 (Altromin-GmbH, Lage/Lippe, Germany) ad libitum
- Water: tap water ad libitum
- Acclimation period: Minimum of five days


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

IN-LIFE DATES: From: 30 Jan 1986 to: 13 Feb 1986

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Individual exposure chambers for nose-only exposure
- Exposure chamber volume: 60 l
- Source and rate of air: Air was supplied by using a compressor at 4 bar, and airflow was constantly adjusted at 800 l/h by using a rotameter.
- Method of conditioning air: Humidified air (100 l/h perfusing a gas wash bottle filled with water) was introduced into the inhalation chamber
- System of generating particulates/aerosols: The test item was injected into the airflow at a constant rate by using a continous infusion apparatus. The primary aerosol generation took place in a 10 l four-neck round-bottom flask. The secondary aerosol (smaller aerosol particulates) finally reached the inhalation chamber via a standpipe.
- Method of particle size determination: The aerodynamic diameter was determined by using the APS 33 Aerodynamik Particle Sizer (TSI Inc., St Paul). Analyses were conducted every 30 min, and hourly the data was saved. At the end of exposure the collected data was statistically evaluated and mean values and standard deviations were determined for 4 time points.
- Treatment of exhaust air: Trapped and neutralised.


TEST ATMOSPHERE
- Brief description of analytical method used: Samples of the aerosol were absorbed in acetone in 3 cascaded gas wash bottles and gas chromatographically analysed.

TEST ATMOSPHERE
- MMAD (Mass median aerodynamic diameter): The aerodynamic diameter was found to be in the range of 0.486 to > 15.4 µm

Analytical verification of test atmosphere concentrations:

yes

Remarks:

gas chromatography

Duration of exposure:

ca. 4 h

Concentrations:

11.2 mg/l (maximum technically attainable concentration)

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: During the exposure period the behaviour of the animals was closely monitored. Then animals were observed twice daily for clinical effects. Animals were weighed post-exposure on days 7 and 14.
- Necropsy of survivors performed: yes

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 11.2 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: maximum attainable concentration

Mortality:

No deaths occurred during the observation period.

Clinical signs:

other: - irregular, fitfully and noisy breathing - gasping - salivation - long legged, uncoordinated- and staggering tread - prone position - retracted stomach flanks - sluggished or vanished corneal reflex and positional reflex and paw flick latency; - anaesth

Body weight:

Body weight was not effected by the treatment.

Gross pathology:

Necropsy revealed no pathological findings.

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:

The test item was tested for acute inhalation toxicity according to the OECD TG 403 and in compliance with GLP. No deaths occurred and clinical signs noted were reversible within 4 days post exposure. The LC50 for both males and females was found to be > 11.2 mg/l. Hence, classification according to Regulation (EC) No. 1272/2008 is not warranted.