Pine, Pinus mugo, ext.

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:

2013-06-17 to 2013-07-31

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

Aerobic activated sludge (microorganisms from a domestic wastewater treatment plant) was supplied by the sewage works of Rossdorf, Germany.
The aerobic activated sludge used for this study was washed by centrifugation and the supernatant liquid phase was decanted. The solid material was re-suspended in tap water and centrifuged again. This procedure was done three times. An aliquot of the final sludge suspension was weighed, dried
and the ratio of wet sludge to its dry weight was determined.
Based on this ratio, calculated aliquots of washed sludge suspension, corresponding to 3.5 g dry material per litre were mixed with test water. This suspension was aerated overnight and was used for the experiment.

Duration of test (contact time):

28 d

Initial conc.:

77.7 mg/L

Based on:

test mat.

Initial conc.:

253.7 mg/L

Based on:

ThOD/L

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

The test flasks were incubated at 22 ± 1 °C. The The pressure decrease in the reaction vessels was measured over complete experimental phase of 28 days. The test flasks were closed gas-tight by a measuring head. Potassium hydroxide solution (45%) was used for trapping the produced carbon dioxide. The amount of O2 consumed by the activated sludge was calculated from the decrease of pressure in the reaction vessel.

Test conditions: climatised room 22 +-1°C
Light: Darkness
pH-value of thest solutions: 7.6 (measured at the start of the test ; 7.6 - 7.8 (measured at the end of the test)

Reference substance:

benzoic acid, sodium salt

Preliminary study:

no data

Test performance:

no data

Parameter:

% degradation (O2 consumption)

Value:

83

Sampling time:

28 d

Details on results:

no data

Results with reference substance:

The reference item sodium benzoate was sufficiently degraded to 85% after 14 days and to 91% after 28 days of incubation.

no data

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Dwarf Pine oil undergoes 83% biodegradation after 28 days in the test conditions. Biodegradation starts on day 3 and reached 67% at day 13. The 10 day window criterion is therefore meet. The curves obtained with the reference substance alone and with Pine needle oil + reference substance show no toxic effect of Dwarf Pine oil on the micro-organisms at the test concentration.

Executive summary:

Dwarf Pine oil undergoes 83% biodegradation after 28 days in the test conditions in a 301F study. Biodegradation starts on day 3 and reached 67% at day 13. The 10 day window criterion is therefore meet.

Therefore, Dwarf Pine oil is considered to be readily biodegradable.

The curves obtained with the reference substance alone and with Pine needle oil + reference substance show no toxic effect of Pine needle oil on the micro-organisms at the test concentration. Therefore under the test condition Pine needle oil is considered as ready biodegradable.

Description of key information

Dwarf Pine oil undergoes 83% biodegradation after 28 days under a 301F study. Dwarf Pine oil met the 10-day window criterion. 
The curves obtained with the reference substance alone and with Dwarf Pine oil + reference substance show no toxic effect of Dwarf Pine oil on the micro-organisms at the test concentration. Dwarf Pine oil is considered as ready biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Dwarf Pine oil undergoes 83% biodegradation after 28 days under a 301F study. Dwarf Pine oil met the 10-day window. The curves obtained with the reference substance alone and with Pine needle oil + reference substance show no toxic effect of Dwarf Pine oil on the micro-organisms at the test concentration.

Therefore Dwarf Pine oil is considered as ready biodegradable.