Chlorodimethylvinylsilane

Toxicity to microorganisms

Description of key information

Toxicity to microorganisms: 3hr ASRI EC10 >100 mg/l (loading rate) (OECD 209), read across from a structurally-related substance.

Key value for chemical safety assessment

EC10 or NOEC for microorganisms:

100 mg/L

Additional information

There are no reliable microorganism toxicity data available for chloro(dimethyl)vinylsilane (CAS 1719-58-0), therefore good quality data for the structurally-related substance dichloro(methyl)(vinyl)silane (CAS 124-70-9), have been read across.Both substances hydrolyse very rapidly and have structurally similar silanol hydrolysis products, dimethyl(vinyl)silanol and methyl(vinyl)silanediol, respectively. In view of the very rapid hydrolysis, it is the silanol hydrolysis product that is relevant for environmental risk assessment.

The other hydrolysis product is hydrogen chloride for both substances. Hydrogen chloride is not expected to have adverse effects on microorganisms in a sewage treatment plant, where the pH is maintained within a favourable range.

Chloro(dimethyl)vinylsilane(CAS 1719-58-0) and dichloro(methyl)(vinyl)silane (CAS 124-70-9) are within an analogue group of substances within which, in general, there is no evidence of significant toxicity to microorganisms.

This analogue group for the toxicity to microorganisms endpoint consists of a number of sub-classes of substances (based on structure/functionality) with different main codes (used to represent the different sub-classes). However, read-across is carried out between substances with the same main code in most cases.

The table below presents microorganism toxicity data available for substances within the sub-class (I-2) of alkoxysilanes, silanols, acetoxysilanes and chlorosilanes, etc, where the Si part is of low-biological reactivity, once any hydrolysis is accounted for. Chloro(dimethyl)vinylsilane (CAS 1719-58-0) anddichloro(methyl)(vinyl)silane (CAS 124-70-9) are members of this sub-class.

It is therefore considered valid to read-across the results for dichloro(methyl)(vinyl)silane (CAS 124-70-9) to fill the data gap for the registered substance.Additional information is given in a supporting report (PFA, 2013j) attached in Section 13 of the IUCLID 5 dossier.

 

Table Microorganism toxicity data for substances within the relevant sub-class (I-2) of chemicals

CAS	Chemical Name (CAS Name)	Guideline Number	Test method	Species	PFA Klimisch code	Duration	Result: E(I)C50 (mg/l)	Result: NOEC (Or EC10/EC20) (mg/l)
001066-40-6	Hydroxytrimethylsilane	OECD 209 and ISO 1892	ASRI		2	Uncertain	6670
031795-24-1	Potassium methylsilanetriolate	OECD 209	ASRI		1a	3 h		EC10 >100 mg/l
139147-73-2	Silane, dichlorodicyclopentyl-	OECD 209	ASRI		1a	3 hr	>100
000124-70-9	Dichloro(methyl)(vinyl)silane	OECD 209	ASRI		1a	3hr	>100 mg/l	EC10 >100 mg/l
126990-35-0	Dicyclopentyldimethoxysilane	OECD 209/EU C11/Huls AG method (WOE)	ASRI/ASRI/oxygen consumptionP. putida(WOE)		1a/1a/2c -don't use to derive PNEC* (WOE)	3 hr; 3hr; 3hr(WOE)	>water solubility; >water solubility; >water solubility (WOE)
001000-50-6	Butylchlorodimethylsilane	88/302/EC	ASRI		1a	3h	>340
013154-25-1	Chlorotri(3-methyl-propyl)silane	OECD 209	ASRI		2b	3 hr	>1000 (nominal, parent)	100 (nominal, parent)
005894-60-0	Trichloro(hexadecyl)silane	OECD 209	ASRI		1a	3h	>1000	≥1000 mg/l Nitrification control indicated no heterotrophic inhibition of respiration rate
000075-94-5	Trichloro(vinyl)silane	OECD 209	ASRI		1a	3hr	>100 mg/l
001185-55-3	Trimethoxy(methyl)silane	OECD 209	ASRI		1a	3hr	>100 mg/l	EC10 >100 mg/l
017980-47-1	Triethoxyisobutylsilane	OECD 209	ASRI		1a	3h	>1000mg/l	≥1000 mg/l
002943-75-1	Triethoxyoctylsilane	OECD 209	ASRI		1a	3 hr	>1000	≥1000 mg/l Nitrification control indicated no heterotrophic inhibition of respiration rate
016068-37-4	4,4,7,7-tetraethoxy-3,8-dioxa-4,7-disiladecane	DIN 38 412, Part 8 (Pseudomonas cell multiplication inhibition test)	growth inhibition test	P. putida	1c	16 h	>8000 mg/l	8000 mg/l
035435-21-3	Triethoxy(2,4,4-trimethylpentyl)silane	OECD 209	ASRI		1a	3hr	>100 mg/l
087135-01-1	1,6-Bis(trimethoxysilyl)hexane	OECD 209	ASRI		1a	3h	>1000 mg/l
016415-12-6	Hexadecyltrimethoxysilane	OECD 209	ASRI		1a	3 hr	>1000	Nitrification control indicated no heterotrophic inhibition of respiration rate.
018395-30-7	Trimethoxy(2-methylpropyl)silane	Huls AG method	oxygen consumption	P. putida	2c -don't use to derive PNEC*	5.8 h		EC10 1.3 ml/l
002768-02-7	Trimethoxyvinylsilane	Huls AG method	oxygen consumption	P. putida	2c -don't use to derive PNEC*	5 h		EC10 1.1 ml/l
142877-45-0	Silane, trimethoxy(1,1,2-trimethylpropyl)-	OECD 209	ASRI		1a	3 hr	>1000	≥1000 mg/l

* Emulsifier nonylphenol ethoxylate propoxylate used. Results should be used with caution. Also, reference substance not used.

In the study with dichloro(methyl)(vinyl)silane (CAS 124-70-9), an activated sludge respiration inhibition 3 hour EC₁₀value of >100 mg/l (loading rate) was reported. An EC50 >100 mg/l was reported by the study authors. 6%and 3% inhibition was observed at 100 mg/l in the test. This is considered by the reviewer of this study toindicate an EC10 of >100 mg/l.

The study is considered to be reliability 1 (reliable without restrictions); the read across of the result is considered to be reliability 2 (reliable with restrictions).

References:

PFA, 2013j, Peter Fisk Associates, STP Microorganism toxicity Main Analogue Group report, PFA.300.003.006