acrylic acid, 3-(trimethoxysilyl)propyl ester

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:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

other: Japanese guidelines for testing of chemicals “Ready biodegradability of chemical substance by microbe”

GLP compliance:

yes

Oxygen conditions:

not specified

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

> 0 - <= 28 d

Parameter followed for biodegradation estimation:

test mat. analysis

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

No details available

Reference substance:

aniline

Parameter:

% degradation (O2 consumption)

Value:

26

Sampling time:

7 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 41

Sampling time:

28 d

Details on results:

No details available.

Key result

Parameter:

BOD5

Value:

ca. 0.67 g O2/g test mat.

Key result

Parameter:

COD

Value:

1.64 g O2/g test mat.

Results with reference substance:

The reference substance attained 71% degradation by study day 7.

Inhibition of microbial activity

Comments: The biodegradation rate of the material was 41% after 28-day exposure to sludge. It was fully determined by chemical analysis that the 41% could be attributed to the complete biodegradation of methanol, produced from hydrolysis of the material.

This result indicates that the material has no inhibitory effect to any bacteria in biodegradation procedure.

Ready biodegradability

Degradation: 41%

Classification: not readily biodegradable

Reference substance: aniline

Experimental values:

Test substance		Reference substance
Day	Percentage %	Day	Percentage %
7	26	7	71
28	41	28	75

 

See attachment for degradation curve.

 

Biological oxygen demand

Biological oxygen demand measured over 5 days = 0.67 g O₂/g (BOD) at 28 day exposure.

Chemical oxygen demand = 1.64 g O₂/g (COD)

BOD/COD = 41%

Comments: It was demonstrated by chemical analysis that the BOD value was due to the biodegradation of methanol produced by the hydrolysis of the substance.

Validity criteria fulfilled:

yes

Remarks:

Based on the limited information available

Interpretation of results:

not readily biodegradable

Conclusions:

The biodegradation rate of the substance was determined to be 41% after 28-day exposure to sludge. However, this was due to the complete biodegradation of the methanol hydrolysis product. Therefore, the substance was classified as 'not readily biodegradable'.

Description of key information

Biodegradation in water, screening tests: 41% in 28 days (O₂ consumption). The silanol hydrolysis product, 3-acryloxypropylsilanetriol, is not expected to biodegrade to any significant extent.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

A biodegradation of 41% in 28 days (O₂ consumption) was determined in a reliable study conducted according to an appropriate test protocol, and in compliance with GLP.

In contact with water, the submission substance hydrolyses rapidly to form 3-acryloxypropylsilanetriol and methanol. Hydrolysis of the parent submission substance is expected to be significant during the cause of the biodegradation study. Therefore, the biodegradation observed is expected to be as a result of the methanol hydrolysis product.

No significant biodegradation is expected for the silanol hydrolysis product; 3-acryloxypropylsilanetriol.

Methanol is readily biodegradable (OECD 2004).

Reference:

OECD (2004): SIDS Initial Assessment Report for SIAM 19, Berlin, Germany, 18-20 October 2004, Methanol, CAS 67-56-1.