1H-Imidazole-1-ethanol, 4,5-dihydro-, 2-nortall-oil alkyl derivs.

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: simulation testing on ultimate degradation in surface water

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 19 November 1997 and 17 December 1997.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of the relevant results. The study report was conclusive, done to a valid guideline and the study was conducted under GLP conditions.

Qualifier:

according to guideline

Guideline:

OECD Guideline 306 (Biodegradability in Seawater)

Deviations:

no

GLP compliance:

yes

Radiolabelling:

no

Oxygen conditions:

aerobic

Inoculum or test system:

natural water

Duration of test (contact time):

28 d

Initial conc.:

1.24 mg/L

Based on:

test mat.

Initial conc.:

2 550 000 mg/L

Based on:

COD

Initial conc.:

2.74 other: mg/mg test substance

Based on:

ThOD/L

% Degr.:

28

Parameter:

DOC removal

Sampling time:

28 d

Remarks on result:

other: O2 consumption by nitrification was taken into account

Transformation products:

not measured

The test substance has a potential for biodegradation in the marine environment if it has been degraded more than 60% within 28 days. The test substance PR-471 was degraded by 28% after 28 days based on COD calculations and measurements to account for O2 consumption by nitrification (Table 1). The nitrate levels in the samples containing test substance are not exceeding the background nitrate levels in the test medium and therefore no nitrification process of the test substance took place.

Validity criteria as for the test are fulfilled

Based on this results, the test substance is ot readily biodegradable in the marine environment.

Table 1. % biodegradation of the inoculum control, the test substance PR-471 and the control of inhibitory action.

Time (days)	% Biodegradation
	Inoculum control	Test substance	Control of inhibitory action
5	68	15	45
15	73	15	56
28	78	28*	56

* oxygen consumption due to nitrification is taken into account

Validity criteria fulfilled:

yes

Conclusions:

The test substance PR-471 is not readily biodegradable in the marine environment.

Executive summary:

Biodegradation testing has been performed on the test substance PR-471 based on OECD guideline 306 for testing chemicals: " Biodegradability in seawater" - Closed Bottle Test. The test substance PR-471 was degraded by 28% after 28 days based on COD calculations and measurements to account for O2 consumption by nitrification.

Description of key information

Biodegradation testing has been performed on the substance based on OECD guideline 306 for testing chemicals: " Biodegradability in seawater" - Closed Bottle Test. The substance was degraded by 28% after 28 days based on COD calculations and measurements to account for O2 consumption by nitrification.

Additional information

The results of the OECD 306 biodegradation study, which would be applied because the pattern of use and disposal of the chemical in question indicated a route to the sea, give a first impression of biodegradability in seawater. It is expected that prolonged exposure would lead to a similar biodegradation as is observed in the study in fresh water. Therefore it can be concluded that the substance is inherently biodegradable.