Tripotassium propylsilanetriolate

Biodegradation in water: screening tests

Description of key information

Biodegradation in water, screening tests: 0% in 28 days (OECD 310), read-across from a structurally-related substance

Additional information

There are no reliable ready biodegradation data available for tripotassium propylsilanetriolate (CAS 93857-00-2), therefore good quality data for the structurally-related substance, hydroxytrimethylsilane (CAS 1066-40-6), have been read across.

Tripotassium propylsilanetriolate and hydroxytrimethylsilane are within a wider analogue group of substancesthan the silanol analogue group discussed in Section 1.3. Substances within this wider analogue group, in general, exhibit no evidence of any significant biodegradation once hydrolysis and subsequent biodegradation of alkoxy/acetoxy groups has been taken into account.

This wider analogue group for the ready biodegradability endpoint consists of a number of sub-classes of substances. However, read-across is carried out between substances with the same sub-class in most cases.

Table 4.1.3 presents ready biodegradation 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.Tripotassium propylsilanetriolate and hydroxytrimethylsilaneare members of this sub-class.

It is therefore considered valid to read-across the results for hydroxytrimethylsilane to fill the data gap for the registered substance.

Table 4.1.3Ready biodegradation data available for substances within the relevant sub-class (I-2) of chemicals

CAS	Name	Readily biodegradable? Yes/no	Result: Biodegradation after 28 day	Guideline	Reliability	Corrected % biodegradation once alkoxy/acetoxy biodegradation is accounted for
1066-40-6	Hydroxytrimethylsilane	No	0%	OECD 310	1	0
18748-98-6	Trimethyl(octadecyloxy)silane	No	68%	OECD 301B	1	-18 (i.e.0)
17689-77-9	Triacetoxyethylsilane	Yes	74% in 21 days	EC C4-A	1	-1 (i.e.0)
1067-25-0	Trimethoxypropylsilane	No	54%	Annex V C4-A	1	4
2943-75-1	Triethoxyoctylsilane	No	31.5%	OECD 301D	1	-11 (i.e.0)
16415-13-7	Triethoxyhexadecylsilane	No	43%	MITI	1	16
87135-01-1	1,6-Bis(trimethoxysilyl)hexane	Yes, but not meeting 10-day window	74%	OECD 301B	1	24
None45	Mixture of 1,1- and 1,2-bis(trimethoxysilyl)ethane	Yes	93%	"Biodegradation study of chemical substances by microorganisms and the like " stipulated in "Testing Method for New Chemical Substances etc." ( Kanhogyo No.5, Yakuhatsu 615, 49Kikyoku No.392, July 13, 1974 )	1	18
13154-25-1	Chlorotri(3-methyl-propyl)silane	No	0%	OECD 301B	1	0
35435-21-3	Triethoxy(2,4,4-trimethylpentyl)silane	No	13%	OECD310	1	-30 (i.e.0)
18395-30-7	Trimethoxy(2-methylpropyl)silane	No	36 - 47%	OECD 301B	1	4
142877-45-0	Silane, trimethoxy(1,1,2-trimethylpropyl)-	No	31%	OECD 301D	1	-2 (i.e.0)
17980-47-1	Triethoxyisobutylsilane	Yes	75%	OECD 301D	1	15
126990-35-0	Dicyclopentyldimethoxysilane	No	12%	OECD 301C	1	-5 (i.e. 0)
139147-73-2	Silane, dichlorodicyclopentyl-	No	0.8%	OECD 301D	2	1
17865-32-6	Cyclohexyldimethoxymethylsilane	No	15-17%	OECD 301D	1	-5 (i.e. 0)
None46	t-butoxycyclopentyldimethoxysilane	No	15%	OECD 301C	1	7
98-12-4	Cyclohexyltrichlorosilane	No	0%	OECD 301C	1	0
124-70-9	Dichloro(methyl)(vinyl)silane	No	-6.78%	OECD 301 A	1	0
1067-53-4	Tris(2-methoxyethoxy)vinylsilane	Yes	89%	Annex V C4-A	1	7
2768-02-7	Trimethoxyvinylsilane	No	51%	OECD 301F	1	-9 (i.e. 0)

 

Additional information is given in a supporting report (PFA, 2013f) attached in Section 13 of the IUCLID 5 dossier.

Hydroxytrimethylsilane attained 0% biodegradation in 28 days.