Trimethylsilane

Endpoint summary

Description of key information

Acute inhalation whole body exposure LC50 was greater than 5400 mg/m3 (DCC, 2001).

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2001-07-06 to 2001-07-20

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

The highest concentration tested was not the maximum achievable concentration.

Qualifier:

according to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

yes

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Raleigh, North Carolina, RO2 Facility
- Age at study initiation: 8-9 weeks
- Weight at study initiation: Females: 128.3 - 134.3g; males: 166.1 - 173.4g
- Fasting period before study: no data
- Housing: Suspended wire-mesh cages above Bed-O'Cob bedding
- Diet (e.g. ad libitum): Purina Rodent Chow ad libitum
- Water (e.g. ad libitum): reverse osmosis treated tap water ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 66-77°F, equivalent to 19-25°C
- Humidity (%): 30-70
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: approx 10th June to: 20th July 2001

Route of administration:

inhalation: gas

Type of inhalation exposure:

whole body

Vehicle:

clean air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Rochester-type, stainless steel and glass whole-body exposure chamber
- Exposure chamber volume: 450 litres
- Method of holding animals in test chamber: stainless steel wire mesh cages
- Source and rate of air: compressed air from Nash compressor at approx. 116 L/min
- Method of conditioning air: passed through Wilkerson model WRA-0025-01-1 dehumidifier and particulate filters (Matheson 460, Balston A915A-DX, A915A-Bx
- System of generating vapour: test article supplied in cylinder as liquefied gas. The cylinder was inverted such that the test article exited as a liquid, which was directed via stainless steel tubing to a heat-reacted (40-60 degrees C) metal J-tube containing a column of stainless steel ball bearings. A stream of compressed air was passed through the J-tube. The test article entering the J-tube was mixed with the air stream and then directed into the chamber inlet.
- Method of particle size determination: not applicable.
- Treatment of exhaust air: not stated
- Temperature, humidity, pressure in air chamber: 22.3 - 23.7 degrees C, 45.8-51.3% RH, -0.6" water.

TEST ATMOSPHERE
- Brief description of analytical method used: GC/FID
- Samples taken from breathing zone: yes

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

1774 ppm (1738-1827 ppm)

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: observed at least once daily, weighed Days 1, 8 and 15
- Necropsy of survivors performed: yes

Statistics:

Group mean values and standard error of the mean calculated by Microsoft Excel where appropriate.

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 1 774 ppm

Based on:

test mat.

Exp. duration:

4 h

Mortality:

None

Clinical signs:

other: None considered to be test article-related.

Body weight:

No treatment-related effects.

Gross pathology:

No treatment-related effects.

Interpretation of results:

GHS criteria not met

Conclusions:

The whole-body vapour inhalation LC50 value for trimethylsilane in the Fischer 344 rat is greater than 1774 ppm (5.4 mg/L, 5400 mg/m3), the highest concentration tested.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5 400 mg/m³ air

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

In an acute inhalation whole-body exposure study of trimethylsilane (DCC, 2001) there were no mortalities or remarkable findings. The 4-hour LC₅₀ value was found to be greater than 5400 mg/m³ (5.4 mg/L, 1774 ppm) which was the highest concentration tested.

Justification for classification or non-classification

Based on the available information trimethylsilane does not require classification for acute toxicity according to Regulation (EC) No 1272/2008.