4-chlorophenol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

other: Peer-reviewed journal article (published literature)

Adequacy of study:

weight of evidence

Study period:

1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Collection of results published in review article

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 302 A (Inherent Biodegradability: Modified SCAS Test)

Version / remarks:

Soil and sediment sample tests reported in the study appear to have studied according to a protocol equivalent or similar to OECD 302.

Deviations:

not specified

Qualifier:

no guideline available

Principles of method if other than guideline:

The study authors additionally perform calculations, which agree with the reported soil/sediment studies; references for the methodology are provided in the published journal article, and the journal article has been peer-reviewed.

GLP compliance:

not specified

Inoculum or test system:

natural soil

Remarks:

A selection of field-samples of natural sediments and soils, plus theoretical calculations.

Details on inoculum:

The authors report on results from both calculations and sampling of natural sediments and soils, with good consistency between the various result-types.

Parameter:

% degradation (O2 consumption)

Value:

50

Sampling time:

30 d

Remarks on result:

other: Not readily biodegradable

Remarks:

Maximum reported time. Possibly inherently biodegradable; however study only considered primary degradation.

Details on results:

Indication is provided that the substance may be inherantly biodegradable, but only primary-degradation is considered, and ready-biodegradability criteria are not met. Author concludes from both field-studies and calculations that the substance is not readily-biodegradable. With an assumed value of 3-30 L/kg of the test item in aerobic soil, the calculated half-life was 3-22d and the values reported in field-studies conducted by methods similar or equivalent to OECD302 ranged from 1-30d.

Indication is provided that the substance may be inherantly biodegradable, but only primary-degradation is considered, and ready-biodegradability criteria are not met. Author concludes from both field-studies and calculations that the substance is not readily-biodegradable. With an assumed value of 3-30 L/kg of the test item in aerobic soil, the calculated half-life was 3-22d and the values reported in field-studies conducted by methods similar or equivalent to OECD302 ranged from 1-30d.

Interpretation of results:

not readily biodegradable

Conclusions:

Indication is provided that the substance may be inherantly biodegradable, but only primary-degradation is considered, and ready-biodegradability criteria are not met. Author concludes from both field-studies and calculations that the substance is not readily-biodegradable. With an assumed value of 3-30 L/kg of the test item in aerobic soil, the calculated half-life was 3-22d and the values reported in field-studies conducted by methods similar or equivalent to OECD302 ranged from 1-30d.

Executive summary:

Indication is provided that the substance may be inherantly biodegradable, but only primary-degradation is considered, and ready-biodegradability criteria are not met. Author concludes from both field-studies and calculations that the substance is not readily-biodegradable. With an assumed value of 3-30 L/kg of the test item in aerobic soil, the calculated half-life was 3-22d and the values reported in field-studies conducted by methods similar or equivalent to OECD302 ranged from 1-30d.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

2020

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Remarks:

results derived from a valid (Q)SAR model and falling into its applicability domain, with adequate and reliable documentation / justification

Qualifier:

according to guideline

Guideline:

other: REACH guidance on QSARs R.6

Deviations:

not applicable

GLP compliance:

not specified

Parameter:

probability of ready biodegradability (QSAR/QSPR)

Remarks on result:

not readily biodegradable based on QSAR/QSPR prediction

Details on results:

The model predicts the test-item to not be readily biodegradable. The model suggests a modest possibility of primary degradation but not ultimate degradation within the relevant time window.

Interpretation of results:

not readily biodegradable

Conclusions:

The assessment indicates that the prediction is suitable for the regulatory conclusion set out in section 4.1.; although at higher tonnage levels (Annex VIII and above) additional information is recommended to be provided in accordance with the tonnage driven information requirements. This conclusion is with due regard to REACH Article 25(1) and impact on the weight of evidence including new physicochemical, environmental fate and/or newly generated in vitro information. The monoconstituent substance does not meet the criteria of being readily biodegradable.

Executive summary:

The outcome of the model for all constituents and impurities are considered suitable to support the assessment of the ready biodegradability of the substance. The model indicates that the main constituent of the substance is not readily-biodegradable, and is unlikely to exceed the 60 % pass level set by the OECD Guidelines for testing of Chemicals (301) for ready biodegradability of a substance, which is consistent with other information available in published, peer-reviewed literature. Additionally, this prediction is intended as supporting information in a weight-of-evidence approach for the endpoint, in support of published information that shows the substance to not be readily biodegradable.

Description of key information

Biodegradation: not readily biodegradable; possibly inherantly biodegradable, primary-degradation half-life 1 -30d, (weight of evidence approach, 2020).

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Type of water:

freshwater

Additional information

Biodegradation: not readily biodegradable; possibly inherantly biodegradable, primary-degradation half-life 1 -30d, (weight of evidence approach, 2020).