2,2,4-trimethyl-1-oxa-4-aza-2-silacyclohexane

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1969

Report date:

1969

Materials and methods

Principles of method if other than guideline:

- Principle of test:
1) Dynamic spray inhalation equipment (NIESSEN et al., 1963)
2) Static spray inhalation
- Short description of test conditions:
1) spraying of test substance mixed with alcohol and lutrol (1:1), absorbent: cotton for absorption of spray mist containing test substance; 3 air concentrations (nominal: 0.25, 0.5, 1, 2.5, 2.5 mg/L, analytical: 0.064, 0.141, 0.296, 0.662, 0.9 mg/L, 5 dose groups), exposure time 4 hours; 2 weeks observation
2) spraying of test substance mixed with alcohol and lutrol (1:1) every 30 min within 4 hours of total exposure; air agitation by use of fan; rabbits, guinea pigs, rats and mice together exposed in respective 2 m³ test chamber; 2 weeks observation

- Parameters analysed / observed:
1) clinical signs; lethal concentration
2) clinical signs

GLP compliance:

no

Remarks:

study conducted prior to implementation of GLP

Test type:

traditional method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2,2,4-trimethyl-1-oxa-4-aza-2-silacyclohexane

EC Number:

233-487-5

EC Name:

2,2,4-trimethyl-1-oxa-4-aza-2-silacyclohexane

Cas Number:

10196-49-3

Molecular formula:

C6H15NOSi

IUPAC Name:

2,2,4-trimethyl-1,4,2-oxazasilinane

Test material form:

liquid

Details on test material:

Batch number: 20140202

Specific details on test material used for the study:

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Final dilution of a dissolved solid, stock liquid or gel: Aktivator MO mixed with alcohol and lutrol (1:1)

Test animals

Species:

rat

Strain:

Wistar

Remarks:

Wistar II

Sex:

male/female

Administration / exposure

Route of administration:

other: two tests with aerosols/spray mist

Type of inhalation exposure:

whole body

Vehicle:

other: alcohol and lutrol (1:1)

Remark on MMAD/GSD:

MMAD was not determined

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus:test 1: Dynamic spray inhalation equipment (NIESSEN et al., 1963), test 2: static spray inhalation chamber
- Exposure chamber volume: unknown for test 1 (dynamic spray inhalation); 2 m³ test 2 (static spray inhalation)

TEST ATMOSPHERE
- Samples taken from breathing zone: collection of samples for calculation of average concentration in air, but location of sample collection was not reported

VEHICLE
- Composition of vehicle (if applicable): alcohol and lutrol
- Concentration of test material in vehicle (if applicable): unknown

Analytical verification of test atmosphere concentrations:

not specified

Remarks:

Report stated analytical concentration values but neither sample collection method, location and time point of sample collection nor type of analytical verification was reported

Duration of exposure:

4 h

Concentrations:

Test 1 (dynamic spray inhalation, males/females): theoretical concentrations: males: 0.25, 1, 2.5 mg/L (single exposure) and 0.5 and 2.5mg/L (repeated exposure; 5 x), females: 2.5 mg /L; measured concentrations: 0.064, 0.141, 0.296, 0.662, 0.9 mg/L (males), 0,82 mg/L (females)
Test 2 (static spray inhalation, males): theoretical concentration: 1 mg/L, measured concentration: 0.344 mg/L

No. of animals per sex per dose:

Test 1: 20 males per dose for 0.25, 5 x 0.5, 1, 2.5, 5 x 2.5 mg/L; 20 females per dose 2.5 mg/L
Test 2: 10 male rats

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

male

Dose descriptor:

LC0

Effect level:

2.5 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Result from Test 1

Effect levels 2

Key result

Sex:

female

Dose descriptor:

LC0

Effect level:

2.5 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Result from Test 1

Effect levels 3

Key result

Sex:

male

Dose descriptor:

LC0

Effect level:

2.5 mg/L air (nominal)

Based on:

test mat.

Exp. duration:

20 h

Remarks on result:

other: Result from Test 1 repeated 4h exposure (5x)

Effect levels 4

Key result

Sex:

male

Dose descriptor:

LC0

Effect level:

0.662 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Result from Test 1

Effect levels 5

Key result

Sex:

female

Dose descriptor:

LC0

Effect level:

0.82 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: Result from Test 1

Effect levels 6

Key result

Sex:

male

Dose descriptor:

LC0

Effect level:

0.9 mg/L air (analytical)

Based on:

test mat.

Exp. duration:

20 h

Remarks on result:

other: Result from Test 1; repeated 4h exposure (5 x)

Mortality:

Test 1: none
Test 2: none

Clinical signs:

other: Test 1: clinical signs were observed in all animals only at the highest nominal dose of 2.5 mg/L. Test 2: none

Any other information on results incl. tables

Test 1 (Dynamic spray inhalation)
Species	Concentration in air (mg Aktivator MO/L)		Exposure duration per day	Exposure days	Toxicological findings in 14 days
	theoret.	measured
rat (male)	0.25	0.064	4	1	0/0/20
	1.00	0.296	4	1	0/0/20
	2.50	0.662	4	1	0/20/20
rat (female)	2.50	0.820	4	1	0/20/20
mice (male)	1.00	0.325	4	1	0/20/20
	2.50	0.724	4	1	1/20/20
rat (male)	0.50	0.141	4	5	0/0/20
	2.50	0.900	4	5	0/20/20
*/*/*	deaths/clinical signs/total number of animals
Test 2
no detailed results, species used in this Test: 1 rabbit, 5 guinea pigs, 10 male rats, 20 male mice					No clinical signs or irritation detected for several species

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Conclusions:

For acute toxicity by inhalation only a LC0 was determined. The LC0 for inhalation of the test material in male rats was 2.5 mg/L nominal for both sexes or 0.662 mg/L analytical and in female rats 0.82 mg/L analytical.

Other results are also available for mice, rabbits and guinea pigs from Test 2 (see any other information on results).

Executive summary:

In an acute inhalation toxicity, male and female Wistar II rats were exposed by inhalation route to the test substance in alcohol and lutrol (1:1) in 2 different tests for 4 hours to the whole body at nominal concentrations of 0.25 – 2.5 mg/L. Animals then were observed for 14 days. Due to lack of mortality the LC50 could not be determined.

LC₀Males = 2.5 mg/L (0.662 mg/L)

      Females = 2.5 mg/L (0.820 mg/L)

Other results are also available for mice, rabbits and guinea pigs from Test 2 (see any other information on results).