Methyl-tris acetonoximo-silane

Endpoint summary

Description of key information

No data is available to assess the acute oral toxicity of the target substance Methyl-tris acetonoximo-silane. Thus, available data from a suitable read-across partner are used. In an acute oral toxicity study (OECD 423) with 2-propanone, 2,2’,2”-[O,O’,O”-(ethylsilylidyne)trioxime] no mortality has been reported at a dose of 2500 mg/kg bw. Thus, the oral LD50 can considered to be greater than 2500 mg/kg bw.

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

The source compound EAC3 (2-propanone, 2,2’,2”-[O,O’,O”-(ethylsilylidyne)trioxime], EC No. 611-631-1) is considered a suitable read across partner for the target substance MAC (CAS 2594-75-4). This read-across is based on the hypothesis that source and target substances have similar toxicological properties because:

- structural similarity of the target and the source substances (the presence or absence of additional functional groups or substituents that could influence the behaviour of a chemical),

- similarity in physico-chemical profile of the source and target substances (rapid decomposition in water under cleavage of the same substance (acetone oxime)).

Both substances are similar in terms of the substitution pattern at the silicon atom (i.e. acetoneoximo and methyl group(s)). Both substances exhibit consequently similar physico-chemical properties (rapid decomposition in water, decomposition upon heating to determine boiling point).

Reason / purpose for cross-reference:

read-across source

Preliminary study:

n.a.

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 500 mg/kg bw

Based on:

test mat.

Mortality:

EAC3 did not cause mortality at a dose level of 2500 mg/kg bw.

Clinical signs:

other: Treatment with EAC3 at the dose level of 2500 mg/kg bw caused decreased activity (6/6), hunched back (6/6), prone position (4/6), incoordination (6/6), piloerection (5/6) and creeping gait (3/6). All animals were symptom free from three days after the tre

Gross pathology:

No macroscopic observations were present at a dose level of 2500 mg/kg bw.

Interpretation of results:

GHS criteria not met

Conclusions:

In an acute oral toxicity study in rats conducted according to OECD 423 no mortality occurred at the high dose of 2500 mg/kg bw. Hence, the LD50 value was determined to be greater than 2500 mg/kg bw.

Executive summary:

In an acute oral toxicity study (acute toxic class method, OECD 423), two groups of fasted, 10-11 weeks old, female Wistar rats (3 rats/group) were given a single oral dose of the test item (92.13% purity) in PEG 400 at the dose of 2500 mg/kg bw and were observed for 14 days. All animals survived until the end of the study showing only mild signs of toxicity. The most relevant clinical findings were decreased activity (6/6), hunched back (6/6), prone position (4/6), incoordination (6/6), piloerection (5/6) and creeping gait (3/6). All animals were symptom free from three days after the treatment.

Throughout the 14-day observation period, the body weight showed no indication of a test item-related effect. At necropsy, no treatment-related macroscopic findings were observed in any animal of any step. Based on the results from this study, the oral LD50 in rats is considered to exceed 2500 mg/kg bw.

 

This information is used in a read-across approach in the assessment of the target substance.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

GLP guideline study

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

No data is available to assess the acute oral toxicity of the target substance Methyl-tris acetonoximo-silane. Thus, available data from the suitable read-across partner 2-propanone, 2,2’,2”-[O,O’,O”-(ethylsilylidyne)trioxime] are used.

In an acute oral toxicity study (acute toxic class method, OECD 423), two groups of fasted, 10-11 weeks old, female Wistar rats (3 rats/group) were given a single oral dose of the test item (92.13% purity) in PEG 400 at the dose of 2500 mg/kg bw and were observed for 14 days. All animals survived until the end of the study showing only mild signs of toxicity. The most relevant clinical findings were decreased activity (6/6), hunched back (6/6), prone position (4/6), incoordination (6/6), piloerection (5/6) and creeping gait (3/6). All animals were symptom free from three days after the treatment.

Throughout the 14-day observation period, the body weight showed no indication of a test item-related effect. At necropsy, no treatment-related macroscopic findings were observed in any animal of any step. Based on the results from this study, the oral LD50 in rats is considered to exceed 2500 mg/kg bw.

Justification for classification or non-classification

Based on the available data, the target substance Methyl-tris acetonoximo-silane does not warrant classification for acute toxicity in accordance with regulation (EC) No 1272/2008.