Hydrocarbons, C10-C13, aromatics, <1% naphthalene

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:

Dec 2000 to Jan 2001

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This robust summary has a reliability rating of 2 because the study followed a standard test guideline, there were no deviations from the protocol, however it was not conducted under GLP.

Justification for type of information:

The justification for read across is provided as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Inoculum used as the source of the microorganisms was an aliquot of fresh activated sludge from a domestic wastewater treatment facility in New Jersey, USA.

Duration of test (contact time):

28 d

Initial conc.:

ca. 50 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Test material was tested in triplicate, controls and blanks were tested in duplicate. The amount of oxygen consumed by microorganisms from the oxidation of the test material was continuously monitored by an automated respirometer during the 28-day test period. Test material concentration was approximately 50mg/L. Sodium benzoate (positive control) concentration was 50mg/L. All test vessels were stirred constantly for 28 days using magnetic stir bars and plates.

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

2.44

St. dev.:

2.73

Sampling time:

4 d

Parameter:

% degradation (O2 consumption)

Value:

46.05

St. dev.:

5.04

Sampling time:

5 d

Parameter:

% degradation (O2 consumption)

Value:

51.43

St. dev.:

3.09

Sampling time:

7 d

Parameter:

% degradation (O2 consumption)

Value:

60.04

St. dev.:

2.32

Sampling time:

17 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

69.99

St. dev.:

8.99

Sampling time:

28 d

Details on results:

Test material was readily biodegradable. Half-life was <2 weeks. By day 28, 69.99% degradation of the test material was observed. 10% biodegradation was achieved on approximately day 5, 50% biodegradation on approximately day 7.

By day 14, >60% biodegradation of positive control was observed, which meets the guideline requirement. No excursions from the protocol were noted.

Results with reference substance:

Sodium benzoate, the positive control, achieved 94.42% with a standard deviation of 11.42% degradation after 28 days, and therefore this test may be considered valid.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

Hydrocarbons, C10-C13, aromatics, <1% naphthalene, a multi-component substance, biodegraded to an extent of 70% after 28 days. The data support characterizing the test substance as rapidly biodegradable, readily biodegradable, not expected to persist in the environment under aerobic conditions. Although it did not meet the 10 -day window requirement, it is characterized as readily biodegradable because the criteria is not applied to multi-component substances when assessing their ready biodegradability.

Executive summary:

Hydrocarbons, C10-C13, aromatics, <1% naphthalene, a multi-component substance, biodegraded to an extent of 70% after 28 days. The data support characterizing the test substance as rapidly biodegradable, readily biodegradable, not expected to persist in the environment under aerobic conditions. Although it did not meet the 10 -day window requirement, it is characterized as readily biodegradable because the criteria is not applied to multi-component substances when assessing their ready biodegradability.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20-Oct-1994 to 17-Nov-1994

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This robust summary has a reliability rating of 2 because the study followed a standard test guideline, there were no deviations from the protocol, however it was not conducted under GLP.

Justification for type of information:

The justification for read across is provided as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Inoculum used as the source of the microorganisms was an aliquot of fresh activated sludge from a domestic wastewater treatment facility in New Jersey, USA.

Duration of test (contact time):

28 d

Initial conc.:

ca. 35 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Test material was tested in triplicate, controls and blanks were tested in duplicate. The amount of oxygen consumed by microorganisms from the oxidation of the test material was continuously monitored by an automated respirometer during the 28-day test period. Test material concentration was 35mg/L. Sodium benzoate (positive control) concentration was approximately 50mg/L. All test vessels were stirred constantly for 28 days using magnetic stir bars and plates.

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

2 d

Parameter:

% degradation (O2 consumption)

Value:

17.94

Sampling time:

3 d

Parameter:

% degradation (O2 consumption)

Value:

52.67

Sampling time:

5 d

Key result

Parameter:

% degradation (O2 consumption)

Value:

60.74

St. dev.:

3.43

Sampling time:

28 d

Details on results:

Test material was readily biodegradable. Half-life was <1 week. By day 28, 60.7% degradation of the test material was observed. 10% biodegradation was achieved on approximately day 3, 50% biodegradation on approximately day 5.
By day 14, >60% biodegradation of positive control was observed, which meets the guideline requirement. No excursions from the protocol were noted.

Results with reference substance:

Sodium benzoate, the positive control, achieved 97.33% with a standard deviation of 0.72% degradation after 28 days, and therefore this test may be considered valid.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

Hydrocarbons, C10 -C13, aromatics, >1% naphthalene, a multi-component substance, biodegraded to an extent of 61% after 28 days. The data support characterizing the test substance as rapidly biodegradable, readily biodegradable, not expected to persist in the environment under aerobic conditions. Although it did not meet the 10 -day window requirement, it is characterized as readily biodegradable because the criteria is not applied to multi-component substances when assessing their ready biodegradability.

Executive summary:

Hydrocarbons, C10-C13, aromatics, >1% naphthalene, a multi-component substance, biodegraded to an extent of 61% after 28 days. The data support characterizing the test substance as rapidly biodegradable, readily biodegradable, not expected to persist in the environment under aerobic conditions. Although it did not meet the 10 -day window requirement, it is characterized as readily biodegradable because the criteria is not applied to multi-component substances when assessing their ready biodegradability.

Description of key information

Hydrocarbons, C10-C13, aromatics, <1% naphthalene, biodegraded 70% after 28 days in an aerobic OECD 301F test, and under the conditions of the study and is readily biodegradable.

Hydrocarbons, C10-C13, aromatics, >1% naphthalene, biodegraded 61% after 28 days in an aerobic OECD 301F test, and under the conditions of the study and is readily biodegradable.

This data is read across to Hydrocarbons, C11-C15, aromatics, <1% naphthalene.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable