4-(3-phenylpropyl)pyridine

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

Study period:

05 December 2017 to 03 January 2018

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Deviations:

yes

Remarks:

On Days 18 and 20 of the test, the temperature was recorded as being 25.3 °C and 24.8 ºC respectively; a deviation from the Study Plan that tests maintain temperature of 22 ± 2ºC.

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Version / remarks:

No. 440/2008

Deviations:

yes

Remarks:

On Days 18 and 20 of the test, the temperature was recorded as being 25.3 °C and 24.8 ºC respectively; a deviation from the Study Plan that tests maintain temperature of 22 ± 2ºC.

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

Version / remarks:

The guideline was identified as OCSPP 835.3110 (Paragraph (m)) in the study report.

Deviations:

yes

Remarks:

On Days 18 and 20 of the test, the temperature was recorded as being 25.3 °C and 24.8 ºC respectively; a deviation from the Study Plan that tests maintain temperature of 22 ± 2ºC.

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

The test substance is listed as 4-PPP. The test substance is a clear amber colored liquid. The test substance was obtained from the Sponsor, Vertellus Holdings LLC and stored at room temperature in the dark.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

A mixed population of activated sewage sludge micro-organisms was obtained on 4 December 2017 from the aeration stage of the Severn Trent Water Plc sewage treatment plant at Loughborough, Leicestershire, UK, which treats predominantly domestic sewage.

Duration of test (contact time):

28 d

Initial conc.:

11.7 mg/L

Based on:

test mat.

Initial conc.:

10 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

An amount of test item (35.1 mg) was dispersed in approximately 400 mL of mineral medium with the aid of high shear mixing (approximately 7500 rpm, 15 minutes) prior to dispersal in inoculated mineral medium. The volume was adjusted to 3 liters to give a final concentration of 11.7 mg/L, equivalent to 10 mg carbon/L.

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (CO2 evolution)

Value:

70

Sampling time:

28 d

Details on results:

The test item attained 70% biodegradation after 28 days. Under the strict terms and conditions of OECD Guideline No. 301B the test item cannot be considered to be readily biodegradable as the test item failed to satisfy the 10-Day window validation criterion, whereby 60% biodegradation must be attained within 10 days of the biodegradation exceeding 10%. However, the test item has exhibited the potential for rapid biodegradation.

Validity criteria fulfilled:

yes

Remarks:

IC content 5% & % (protocol ≤ 5%); CO2 emitted by controls 30.38 mg/L (protocol <70 mg/L; difference replicates less than 20% (protocol ≤20 %); degradation positive control 111% at 14 d (protocol ≤14 d), degradation toxicity d 14, 54% (protocol > 25%).

Interpretation of results:

readily biodegradable, but failing 10-day window

Remarks:

The test item attained 70% biodegradation after 28 days but only 10% after 10 days.

Conclusions:

The test item attained 70% biodegradation after 28 days. Under the strict terms and conditions of OECD Guideline No. 301B the test item cannot be considered to be readily biodegradable as the test item failed to satisfy the 10-Day window validation criterion, whereby 60% biodegradation must be attained within 10 days of the biodegradation exceeding 10%. However, the test item has exhibited the potential for rapid biodegradation.

Description of key information

The key study was a CO₂ evolution test conducted in accordance with OECD Guideline 301B. The test item attained 70% biodegradation after 28 days. Under the strict terms and conditions of OECD Guideline No. 301B the test item cannot be considered to be readily biodegradable as the test item failed to satisfy the 10-day window validation criterion, whereby 60% biodegradation must be attained within 10 days of the biodegradation exceeding 10%. However, the test item has exhibited the potential for substantial mineralisation and rapid biodegradation.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable but failing 10-day window

Type of water:

freshwater

Additional information

In a supporting study, the substance exhibited 4% degradation in 28 days in a ready biodegradability closed bottle test; the substance was not shown to be readily biodegradable under the strict conditions of the test.