4,4,7,7-tetraethoxy-3,8-dioxa-4,7-disiladecane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

A detailed description of analytical verification of test concentration is missing, although nominal concentrations have been reported.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

016068-37-4

Cas Number:

016068-37-4

IUPAC Name:

016068-37-4

Constituent 2

Reference substance name:

4,4,7,7-tetraethoxy-3,8-dioxa-4,7-disiladecane

EC Number:

240-212-2

EC Name:

4,4,7,7-tetraethoxy-3,8-dioxa-4,7-disiladecane

Cas Number:

16068-37-4

Molecular formula:

C14H34O6Si2

IUPAC Name:

4,4,7,7-tetraethoxy-3,8-dioxa-4,7-disiladecane

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River
- Age at study initiation: 6-9 weeks
- Weight at study initiation: 155-205 g
- Fasting period before study: not reported
- Housing: standard stainless steel wire mesh bottom cages
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 7 days

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

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION

- Exposure apparatus: Stainless steel and glass exposure chambers, where chamber air was ambient air which had been filtered (hepa and charcoal filters). The test material was introduced in to the chamber through a specifically designed glass J tube, into which the material was metered with a syringe pump. Glass beads and heating tape were used to help vaporize the test material, which was passed into the inlet port at the top of the chamber.

- Exposure chamber volume: 450 litres

- Source and rate of air: Airflow was kept at approximately 12-15 air changes per hour.

- Treatment of exhaust air: Filtered by hepa and charcoal filters and passed through a water cyclone before exhausted through the roof of the building.

- Temperature, humidity, pressure in air chamber: Temperature and humidity were recorded every five minutes and kept in the range of 26-29C and 30-39% relative humidity.

TEST ATMOSPHERE
- Brief description of analytical method used: not described
- Samples taken from breathing zone: not described

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

Analytical verification of test atmosphere concentrations:

not specified

Duration of exposure:

4 h

Concentrations:

Target concentrations: 1, 4, 12 and 25 ppm
Nominal concentrations: 1, 4, 8 and 26 ppm
The saturated vapour concentration of the test material at room temperature is reported to be 40 ppm. The target concentration of 25ppm was considered the highest concentration that could be reasonably produced given the test generating equipment and exposure chamber.

No. of animals per sex per dose:

4 groups of five animals per sex per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: daily observations, weights taken on days 8 and 15
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, organ weights, histopathology, other: respiratory, dermal, behavioural, nasal, ocular changes were all recorded.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 26 ppm

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Equivalent to >0.38 mg/l

Mortality:

No mortality occurred in any of the test animals during exposure.

Clinical signs:

other: No overt signs of toxicity were observed in any of the animals during exposure or observation period.

Body weight:

None reported.

Gross pathology:

Gross pathologic examination of the animals during terminal sacrifice revealed hemorrhagic foci of the lung in two male rats. No abnormalities were observed during microscopic examination of these lungs. The macroscopic finding of lung hemorrhages was interpreted as a terminal event at the time of sacrifice. Any other changes noted in the tissues of all other rats were considered to be typical of incidental findings of rats of this age and strain euthanized in this manner.

Other findings:

None reported.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

An LC50 of >26ppm (vapour) (equivalent to 377 mg/m3 or 0.38 mg/l) is reported for 4,4,7,7-tetraethoxy-3,8-dioxa-4,7-disiladecane in a study conducted according to an OECD guideline but not in compliance with GLP. This was the highest achievable concentration at which no mortality or effects of toxicity were observed.