[3-(2,3-epoxypropoxy)propyl]triethoxysilane

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an appropriate OECD test guideline, and in compliance with GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Aerobic activated sludge from a wastewater treatment plant (ARA Ergolz II, Fullinsdorf, Switzerland) treating predominantly domestic wastewater. The sludge was washed once with tap water by centrifugation and the supernatant liquid phase was decanted. A homogenised aliquot of the final sludge suspension was weighed, thereafter dried and the ratio of wet to dry weight was calculated.

Duration of test (contact time):

28 d

Initial conc.:

104 mg/L

Based on:

test mat.

Initial conc.:

108 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Test temperature: 22°C

- pH: 7.4

- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 500 ml Erlenmeyer flasks

- Number of culture flasks/concentration: Two (104 mg/l and 108 mg/l). Two inoculum controls. Two procedure controls. One abiotic control. One toxicity control.

SAMPLING
- Sampling frequency: Oxygen consumption recorded manually by taking daily readings at least on each working day.

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes
- Abiotic sterile control: Yes
- Toxicity control: Yes

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

53

Sampling time:

28 d

Details on results:

Biodegradation of reference: 90% in 14d
Toxicity control indicated no inhibitory effect.

Table 1: Cumulative biological oxygen demand (BODmgO₂/l) and calculated % degradation over 28 d test

	Time
	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	Mean day 28
BOD (mgO2/l) Test substance R1	6	18	-	-	48	54	62	68	74	-	-	88	92	94	-	100	-	-	106	108	108	110	112	-	-	116	116	118
BOD (mgO2/l) Test substance R2	10	20	-	-	50	56	64	70	76	-	-	88	92	94	-	100	-	-	106	108	108	110	112	-	-	116	116	118
% degradation Test substance R1	3	9	-	-	22	24	28	31	33	-	-	39	41	42	-	45	-	-	47	48	48	49	50	-	-	52	52	53	53
% degradation Test substance R2	5	10	-	-	24	26	30	33	36	-	-	42	44	44	-	47	-	-	49	50	50	51	52	-	-	53	54	54
BOD (mgO2/l) Inoculum control R1	0	0	-	-	2	3	4	4	5	-	-	6	6	7	-	7	-	-	7	7	7	7	7	-	-	8	8	8
BOD (mgO2/l) Inoculum control R2	0	0	-	-	2	2	3	3	3	-	-	4	4	5	-	5	-	-	5	5	5	5	5	-	-	5	5	5
BOD (mgO2/l) Reference substance R1	36	90	-	-	131	138	144	147	149	-	-	156	157	159	-	161	-	-	163	163	164	164	165	-	-	167	167	168
BOD (mgO2/l) Reference substance R2	30	88	-	-	130	136	140	144	146	-	-	152	152	154	-	154	-	-	156	156	156	158	158	-	-	158	158	158
% degradation Reference substance R1	22	54	-	-	77	81	84	86	87	-	-	90	91	92	-	93	-	-	94	94	95	95	95	-	-	96	96	97	94
% degradation Reference substance R2	18	53	-	-	77	80	82	84	85	-	-	88	88	89	-	89	-	-	90	90	90	91	91	-	-	91	91	91
BOD (mgO2/l) Abiotic control	0	0	-	-	0	0	0	0	0	-	-	0	0	0	-	0	-	-	0	0	0	0	0	-	-	0	0	0
BOD (mgO2/l) Toxicity control	49	97	-	-	170	182	194	203	209	-	-	225	229	236	-	242	-	-	249	251	252	253	255	-	-	260	261	262
% degradation Toxicity control	13	26	-	-	45	49	52	54	55	-	-	59	61	62	-	64	-	-	66	66	67	67	67	-	-	69	69	69

 

Validity criteria fulfilled:

yes

Conclusions:

A biodegradation rate of 53% in 28d (oxygen consumption) was determined in a reliable ready biodegradation study conducted according to an appropriate test protocol, and in compliance with GLP.

Description of key information

Biodegradation in water: screening tests: 53% in 28 d (oxygen consumption)

Additional information

A biodegradation rate of 53% in 28d (oxygen consumption) was determined in a reliable ready biodegradation study conducted according to an appropriate test protocol, and in compliance with GLP. [3-(2,3-Epoxypropoxy)propyl]triethoxysilane hydrolyses with a half-life12 – 36 h at pH 7 and 25°C, to ultimately produce 2,3-dihydroxypropoxypropylsilanetriol and ethanol. Ethanol is readily biodegradable.The biodegradation observed in the test is due to the biodegradation of the ethanol hydrolysis product. No significant biodegradation is expected for the silanol hydrolysis product.