6'-(dibutylamino)-3'-methyl-2'-(phenylamino)spiro[isobenzofuran-1(3H),9-(9H)-xanthen]-3-one

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11 August to 08 September 1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study undertaken at GLP accredited laboratory to internationally accepted guidelines.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

EU Method C.6 (Degradation: Chemical Oxygen Demand)

Deviations:

not specified

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, adapted

Details on inoculum:

- Source of inoculum/activated sludge:The aeration stage of the HRC Limited sewage treatment plant treating predominantly domestic sewage.
- Laboratory culture:
- Method of cultivation: Standard nutrient medium added
- Storage conditions: 280 ml BOD bottles (darkened glass) with ground glass stoppers.
- Storage length: 0, 5, 15 and 28 days
- Preparation of inoculum for exposure:
- Pretreatment: incubated as 21 ± 1°C
- Concentration of sludge:
- Initial cell/biomass concentration:
- Water filtered: yes
- Type and size of filter used, if any: Whatman GFA filter paper

Duration of test (contact time):

0 - 28 d

Initial conc.:

2 mg/L

Based on:

act. ingr.

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

5

Sampling time:

28 d

Details on results:

The test substance attained 5% biodegradation after" 28 days and cannot, therefore be considered as readily biodegradable under the strict terms of Annex V.C6.

Sodium benzoate attained 89% degradation within 28 days. Oxygen depletions in the inoculated and non-inoculated control series were within the prescribed limits.

Validity criteria fulfilled:

not specified

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test substance attained 5% biodegradation after 28 days and cannot, therefore be considered as readily biodegradable under the strict terms of Annex V.C6.
Sodium benzoate attained 89% degradation within 28 days.

Reference 2

Endpoint:

biodegradation in water: screening tests

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

16 April to 14 May 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study undertaken at GLP accredited laboratory to internationally accepted guidelines.

Qualifier:

according to guideline

Guideline:

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

Deviations:

not specified

Qualifier:

according to guideline

Guideline:

EU Method C.5 (Degradation: Biochemical Oxygen Demand)

Deviations:

not specified

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, adapted

Details on inoculum:

- Source of inoculum/activated sludge: The aeration stage of the HRC Limited sewage treatment plant treating predominantly domestic sewage.
- Laboratory culture:
- Method of cultivation:
- Storage conditions: 5 litre glass culture vessels (containing 3 litres of culture) fitted with gas-tight lids, sintered glass air stones and magnetic stirrers.
- Storage length:
- Preparation of inoculum for exposure:
- Pretreatment: The sample was aerated for 6 days at test temperature prior to use. This was to facilitate the degradation of background dissolved organic carbon in the sample and thereby, reduce the carryover into the test vessels. Immediately prior to use, the suspended solids content was determined and adjusted using nutrient media.
- Concentration of sludge: 500 mg/l
- Initial cell/biomass concentration:
- Water filtered: yes
- Type and size of filter used, if any:

Duration of test (contact time):

0 - 28 d

Initial conc.:

40 mg/L

Based on:

act. ingr.

Parameter followed for biodegradation estimation:

CO2 evolution

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

2

Sampling time:

28 d

Results with reference substance:

The standard substance, sodium benzoate, attained 61% biodegradation within 28 days, thereby confirming the suitability of the inoculum and the culture conditions.

Validity criteria fulfilled:

not specified

Interpretation of results:

not inherently biodegradable

Conclusions:

ODB-2 attained only 1 - 2% biodegradation at 40 mg/l after 28 days and cannot, therefore, be termed as inherently biodegradable.

Description of key information

In study 29(a), the test substance attained 5% biodegradation after 28 days and cannot, therefore be considered as readily biodegradable under the strict terms of Annex V.C6.

In study 29(b), ODB-2 attained only 1 - 2% biodegradation at 40 mg/l after 28 days and cannot, therefore, be termed as inherently biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed