p-cresol

Biodegradation in water and sediment: simulation tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: sediment simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Biodegradation experiments by methanogenic consortia from Saale river sediment

GLP compliance:

not specified

Oxygen conditions:

anaerobic

Inoculum or test system:

natural sediment

Details on source and properties of sediment:

Black anoxic mud (10 % w/v) collected with Ekman-sampler from river Saale near Jena

Initial conc.:

54 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

Anoxic conditions: 0.5 g/L Na2S x 9 H2O added as reducing agent. Headspace 10 % CO2, 90 % Ar (oxygenfree by passage through Cu filling at 550 °C)

% Degr.:

97

Parameter:

CH4 evolution

Sampling time:

4 wk

Transformation products:

yes

No.:

#1

Details on transformation products:

occurence and removal of several intermediates of degradative pathways were monitored (e.g. 4-hydroxybenzoic acid, benzoate, phenol). no transformation product accumulated.

non-acclimated consortia: turnover rate 3.00 µmol/day/g sediment dw (lag-phase 12 d) acclimated consortia: turnover rate 6.00 µmol/day/g sediment dw (lag-phase 0 d, based on a 24 days incubation period), the CH4 production was 97% of the theoretically possible yield. p-Cresol was not detectable after 3 -4 weeks of incubation.

Degradation product (CAS No./EC No./EINECS Name): 74-82-8 200-812-7 methane

Conclusions:

p-Cresol was not detectable after 3 -4 weeks of incubation

Executive summary:

Anoxic river sediment degraded p-cresol within 3 -4 weeks.

Reference 2

Endpoint:

biodegradation in water: sediment simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Biodegradation was examined in material obtained from a shallow anaerobic

GLP compliance:

not specified

Oxygen conditions:

anaerobic

Inoculum or test system:

other: shallow anaerobic alluvial sand aquifer

Details on source and properties of sediment:

2 sampling sites: 1 methanogenic, 1 sulfate-reducing aquifers. Both aquifers receive leachate from a municipal landfill

Details on inoculum:

50 g [wet weight] of aquifer solids and 50 ml of groundwater

Details on study design:

incubation at room temperature in the dark, quadruplicates preincubation 5 days, addition of 150 to 200 µM test substance

Parent/product:

parent

Compartment:

sediment

Parameter:

test mat. analysis

Sampling time:

46 d

Remarks on result:

other: Time to degradation not given.

Transformation products:

not specified

Details on transformation products:

not analyzed

lag time <10 days under sulfate-reducing and 46 days under methanogenic conditions, no data for complete degradation given. p-Cresol is degraded faster than o-cresol and m-cresol.

Validity criteria fulfilled:

not specified

Conclusions:

p-Cresol is biodegradable in sediment under anaerobic conditions.

Executive summary:

p-Cresol is biodegradable in sediment under anaerobic conditions.

Reference 3

Endpoint:

biodegradation in water: sediment simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: No standard procedure but in accordance with generally accepted scientific standards and described in sufficient detail

Principles of method if other than guideline:

Biodegradation test with natural microorganism communities from water and sediment in the form of e.g. "ecocores"

GLP compliance:

no

Radiolabelling:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

natural water / sediment

Details on source and properties of surface water:

Adaptation of natural microbial communities was measured in ecocore test systems filled with sediment and natural water collected at a river. Parent compound disappearance and mineralization were monitored.

Duration of test (contact time):

120 h

Compartment:

other: water, material (mass) balance

% Recovery:

37.7

St. dev.:

6.3

Compartment:

other: sediment, material (mass) balance

% Recovery:

48.4

St. dev.:

9.6

Compartment:

water

DT50:

>= 9.5 - <= 43 h

Type:

(pseudo-)first order (= half-life)

Temp.:

18 °C

Compartment:

sediment

DT50:

>= 5.9 - <= 11 h

Type:

(pseudo-)first order (= half-life)

Temp.:

18 °C

Compartment:

entire system

DT50:

3 - 16 h

Type:

(pseudo-)first order (= half-life)

Temp.:

18 °C

Remarks on result:

other: "ecocores" (sediment cores)

Transformation products:

not measured

Details on results:

Mineralization was rapid without a lag-phase. Pre-exposure did not accelerate degradation.
Kinetic of test substance degradation:
ca. 50 % after 40 h
ca. 90 % after 70 h
Degradation products: not measured

Mineralization was rapid without a lag-phase. Pre-exposure did not accelerate degradation. Kinetic of test substance degradation: ca. 50 % after 40 h ca. 90 % after 70 h

Degradation products: not measured

Validity criteria fulfilled:

not specified

Conclusions:

p-Cresol was rapidly biodegraded (ca. 90 % after 70 h) in water, water-sediment-suspensions, and by intact sediment-water cores (eco-cores) of marine, estuarine, and freshwater origin. No lag-phase was observed, and pre-exposure did not accelerate degradation.

Executive summary:

p-Cresol was rapidly biodegraded (ca. 90 % after 70 h) in water, water-sediment-suspensions, and by intact sediment-water cores (eco-cores) of marine, estuarine, and freshwater origin. No lag-phase was observed, and pre-exposure did not accelerate degradation.

Reference 4

Endpoint:

biodegradation in water: sediment simulation testing

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

anaerobic p-cresol degradation by sediment samples from a freshwater pond under three reducing conditions: denitrifying, sulfidogenic, and methanogenic

GLP compliance:

no

Oxygen conditions:

anaerobic

Inoculum or test system:

natural sediment

Duration of test (contact time):

>= 3 - <= 4 wk

Initial conc.:

1 mmol/L

Based on:

test mat.

% Degr.:

100

Parameter:

test mat. analysis

Sampling time:

4 wk

Remarks on result:

other: Under denitrifying conditions 10 d for 100 % mineralization

Compartment:

entire system

DT50:

ca. 3 wk

Type:

not specified

Remarks on result:

other: Temperature not specified.

Transformation products:

yes

No.:

#1

Details on transformation products:

Several intermediates of degradation identified. Final degradtion products were methane and carbon dioxide
TS was completely utilized within 21 to 30 days in unacclimated sediment. p-Cresol degradation proceeded through p-hydroxybenzaldehyde and p-hydroxybenzoate under methanogenic and denitrifying conditions. Under methanogenic conditions, also oxidation to benzoic acid took place
Degradation intermediate (CAS No./EC No./EINECS Name): 123-08-0 204-599-1 4-hydroxybenzaldehyde
Degradation intermediate (CAS No./EC No./EINECS Name): 65-85-0 200-618-2 benzoic acid
Degradation intermediate (CAS No./EC No./EINECS Name): 99-96-7 202-804-9 4-hydroxybenzoic acid

TS was completely utilized within 21 to 30 days in unacclimated sediment. p-Cresol degradation proceeded through p-hydroxybenzaldehyde and p-hydroxybenzoate under methanogenic and denitrifying conditions. Under methanogenic conditions, also oxidation to benzoic acid took place

Degradation intermediate (CAS No./EC No./EINECS Name): 123-08-0 204-599-1 4-hydroxybenzaldehyde

Degradation intermediate (CAS No./EC No./EINECS Name): 65-85-0 200-618-2 benzoic acid

Degradation intermediate (CAS No./EC No./EINECS Name): 99-96-7 202-804-9 4-hydroxybenzoic acid

Validity criteria fulfilled:

not specified

Conclusions:

p-Cresol was completely biodegraded within 4 weeks in a freshwater sediment

Executive summary:

p-Cresol was completely biodegraded within 4 weeks in a freshwater sediment.

Description of key information

p-Cresol is biodegraded in aquifer sediment under anaerobic conditions and by anoxic river sediment within 3-4 weeks.

Additional information

The substance is readily biodegradable and no biodegradation simulation test has to be performed for sediments according to REACH Annex IX column 2. However, there are several tests available. p-Cresol was completely biodegraded within 4 weeks in a freshwater sediment. p-Cresol was rapidly biodegraded (ca. 90 % after 70 h) in water, water-sediment-suspensions, and by intact sediment-water cores (eco-cores) of marine, estuarine, and freshwater origin. No lag-phase was observed, and pre-exposure did not accelerate degradation. p-Cresol is biodegraded in aquifer sediment under anaerobic conditions and by anoxic river sediment within 3-4 weeks. This result indicates, that p-cresol is amaerobically biodegradable.