Hydrocarbons, C10-C13, n-alkanes

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

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

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

April to May 2004

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to a standard guideline without deviations from the protocol, but it was not conducted under GLP guidelines.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 306 (Biodegradability in Seawater)

Deviations:

no

GLP compliance:

no

Radiolabelling:

no

Oxygen conditions:

aerobic

Inoculum or test system:

other: Seawater

Details on source and properties of surface water:

The medium was prepared using seawater collected on April 5, 2004 from the Manasquan Inlet, New Jersey, USA, a designated New Jersey Department of Environmental Protection collection site, the salinity was 32 ppt and the DOC was 0.6 ppm C. The collected seawater was aerated and stored in an environmental chamber at 20 degrees C. On Day -1 of the test, mineral salts were added to the seawater and it was aerated.

Details on inoculum:

The inoculum included only the indigenous microorganisms present in the seawater sample.

Duration of test (contact time):

28 d

Details on study design:

The amount of oxygen consumed by the microorganisms from oxidation of the test substance was monitored by an automated respirometer during a 28-day testing period. The control, sodium benzoate, and the test substance were evaluated in duplicate test systems. The amount of oxygen reported for each test system was corrected for oxygen consumption due to endogenous respiration in blank test systems. Temperature range for the 28 day testing period was 22 ± 1 degrees C.

Biodegradation results were calculated by the respirometer software using the theoretical oxygen demand (ThOD) and the mass of the test or positive control substance added. The ThOD was calculated using the empirical formula of each substance and the caclulations as defined in the OECD guideline.

% Degr.:

6.2

St. dev.:

0.5

Parameter:

O2 consumption

Sampling time:

4 d

% Degr.:

11.6

St. dev.:

1.2

Parameter:

O2 consumption

Sampling time:

5 d

% Degr.:

51.6

St. dev.:

5.9

Parameter:

O2 consumption

Sampling time:

11 d

% Degr.:

61

St. dev.:

5.1

Parameter:

O2 consumption

Sampling time:

17 d

Key result

% Degr.:

68.8

St. dev.:

3.3

Parameter:

O2 consumption

Sampling time:

28 d

Remarks on result:

other: The test substance biodegradation was still increasing, albeit slowly, on day 28.

Compartment:

water

DT50:

ca. 10 d

Type:

not specified

Remarks on result:

other: Temperature not specified

Transformation products:

not measured

Evaporation of parent compound:

no

Volatile metabolites:

not measured

Residues:

not measured

Validity criteria fulfilled:

yes

Conclusions:

Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, <2% aromatics, biodegraded to an extent of 69% after 28 days in seawater that used the indigenous microorganisms in the seawater sample as a sole source of the inoculum.

Executive summary:

Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, <2% aromatics, demonstrated a high extent of biodegradation in seawater following a standard OECD test guideline, which suggests that it has the potential to rapidly biodegrade in the marine environment. The test substance biodegraded to an extent of 69% after 28 days in seawater that used the indigenous microorganisms in the seawater sample as a sole source of the inoculum.

Reference 2

Endpoint:

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

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

March to April 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This robust summary has a reliability rating of 1 because the study followed a standard guideline, followed GLP guidelines, and was conducted without deviations that would invalidate the study.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

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:

other: Natural seawater

Details on source and properties of surface water:

Seawater was collected from the Burnham-on-Crouch estuary at high tide. The estuary has no industrial input.

Details on inoculum:

Indigenous microorganisms contined in natural seawater.

Duration of test (contact time):

28 d

Initial conc.:

1.21 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

A surfactant (Nonidet P40) was used to emulsify the test substance. Background BOD for the surfactant was determined by evaluating the BOD of the surfactant alone in parallel test systems.

Reference substance:

acetic acid, sodium salt

% Degr.:

0

Parameter:

O2 consumption

Sampling time:

7 d

% Degr.:

5

Parameter:

O2 consumption

Sampling time:

14 d

% Degr.:

4

Parameter:

O2 consumption

Sampling time:

21 d

Key result

% Degr.:

11

Parameter:

O2 consumption

Sampling time:

28 d

Transformation products:

not measured

Evaporation of parent compound:

not measured

Volatile metabolites:

not measured

Residues:

not measured

Validity criteria fulfilled:

yes

Conclusions:

The test substance biodegraded to an extent of 11% after 28 days.

Executive summary:

The test substance biodegraded to an extent of 11% after 28 days.

Reference 3

Endpoint:

biodegradation in water: sediment simulation testing

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance is readily biodegradable

Transformation products:

not measured

Description of key information

Biodegradation in seawater:

There is no data available for this substance. However, key data is available for structural analogues Hydrocarbons, C11-C14, n-alkanes, isoalkanes; cyclics, <2% aromatics and Hydrocarbons, C12-C14, isoalkanes, <2% aromatics The data is read across to this substance based on analogue read across and a discussion and report on the read across strategy is provided as an attachment in IUCLID Section 13.

Hydrocarbons, C11-C14, n-alkanes, isoalkanes, cyclics, <2% aromatics biodegraded to an extent of 69% after 28 days in seawater that used the indigenous microorganisms in the seawater sample as a sole source of the inoculum.

Hydrocarbons, C12-C14, isoalkanes, <2% aromatics biodegraded to an extent of 11% after 28 days.

Biodegradation in sediment:

This substance is considered readily biodegradable. Therefore, in accordance with REACH Annex IX column 2 exemption, the simulation testing in sediment does not need to be conducted.