Biphenyl-2-ol

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Concentration of test material was reduced to 0.2 and 1.0 mg/L.

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: A sample of activated sludge mixed Iiquor was obtained from the Midland Municipal Wastewater Treatment Plant (Midland, Michigan. USA) on April 28, 1997.
- Concentration of sludge: mixed liquor suspended solids (MLSS) concentration of the activated sludge sample was determined to be 2190 ± 160 mg/L: Based on this determination, the mineral medium (3 liters) was inoculated with 41 ml of activated sludge to yield a final MLSS concentration of 30 ± 1 mg/L.

Duration of test (contact time):

28 d

Initial conc.:

0.2 mg/L

Based on:

test mat.

Initial conc.:

1 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline
- Test temperature: 23 ± 1°C
- pH adjusted: yes, the pH of the inoculated mineral medium was adjusted from 7.01 to 7.37 with 5N NaOH.

TEST SYSTEM
- Culturing apparatus: 1 L flasks were sealed with rubber stoppers fitted with CO2 traps containing 4 ml of 1N NaOH.


CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: yes
- Other: non labelled control

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

33.5

St. dev.:

1.5

Sampling time:

3 d

Remarks on result:

other: 0.2 mg [14C]-OPP

Parameter:

% degradation (CO2 evolution)

Value:

62.5

St. dev.:

0.5

Sampling time:

11 d

Remarks on result:

other: 0.2 mg [14C]-OPP

Parameter:

% degradation (CO2 evolution)

Value:

70.8

St. dev.:

0.3

Sampling time:

28 h

Remarks on result:

other: 0.2 mg [14C]-OPP

Parameter:

% degradation (CO2 evolution)

Value:

35.2

St. dev.:

0.2

Sampling time:

3 d

Remarks on result:

other: 1.0 mg [14C]-OPP

Parameter:

% degradation (CO2 evolution)

Value:

67.7

St. dev.:

0.8

Sampling time:

11 d

Remarks on result:

other: 1.0 mg [14C]-OPP

Parameter:

% degradation (CO2 evolution)

Value:

75.7

St. dev.:

0.5

Sampling time:

28 d

Remarks on result:

other: 1.0 mg [14C]-OPP

Details on results:

70.8 and 75.7% biodegradation (CO2 formation as percentage of theoretical value) after 28 days at low (0.2 mg/L) and high (1.0 mg/L) concentration

Results with reference substance:

Kinetic of control substance: 81% after 2 days

Biodegradation rates of o-phenylphenol (percentage of added radioactivity mineralized to 14CO2):

Day	Abiotic control	Biodegradation at different OPP concentrations
	1.0 mg [14C]-OPP	0.2 mg [14C]-OPP	1.0 mg [14C]-OPP
0	0.0%	0.0%	0.0%
3	0.2%	33.5% (± 1.5)	35.2% (± 0.2)
11	0.3%	62.5% (± 0.5)	67.7% (± 0.8)
28	0.6%	70.8% (± 0.3)	75.7% (± 0.5)

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study modified (no activated sludge used, Rhine river water used instead)

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

Deviations:

yes

Remarks:

instead of deionised water, Rhine river water was used

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

other: inoculum from Rhine river water

Duration of test (contact time):

28 d

Parameter:

% degradation (DOC removal)

Value:

100

Sampling time:

6 d

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP guideline study, some test details are missing

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

28 d

Parameter:

% degradation (O2 consumption)

Value:

ca. 96

Sampling time:

28 d

Details on results:

All ten participants in a ring test reported > 60% biodegradation of 2-phenylphenol after 28 days (mean value = 96%).

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Reference 4

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non-GLP guideline study, with some reporting deficiencies: the pH, temperature, purity of test and reference substance, batch numbers are not described.

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Qualifier:

equivalent or similar to guideline

Guideline:

other: DIN 38412

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, industrial, adapted

Initial conc.:

50 - 400 mg/L

Based on:

DOC

Initial conc.:

200 - 1 000 mg/L

Based on:

COD

Parameter followed for biodegradation estimation:

DOC removal

Parameter:

% degradation (DOC removal)

Value:

100

Sampling time:

10 d

Validity criteria fulfilled:

not specified

Interpretation of results:

inherently biodegradable

Reference 5

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 E (Ready biodegradability: Modified OECD Screening Test)

GLP compliance:

not specified

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: domestic sewage from 10 L laboratory system
- Laboratory culture: yes

Duration of test (contact time):

16 d

Initial conc.:

20 mg/L

Based on:

DOC

Initial conc.:

41.3 other: ml/900ml medium

Based on:

test mat.

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline

TEST SYSTEM
- Number of culture flasks/concentration: 2


SAMPLING
- Sampling frequency: Sampling after 0 h, 1 d, 2 d, 3 d, 4 d, 8 d, 9 d, 11 d, 14 d, 15 d and 16 d


CONTROL AND BLANK SYSTEM
- Inoculum blank: 2

Reference substance:

aniline

Parameter:

% degradation (DOC removal)

Value:

12

Sampling time:

2 d

Parameter:

% degradation (DOC removal)

Value:

88

Sampling time:

9 d

Parameter:

% degradation (DOC removal)

Value:

94

Sampling time:

9 d

Parameter:

% degradation (DOC removal)

Value:

100

Sampling time:

14 d

Results with reference substance:

Kinetic of control substance (in %):
= 25 after 2 day(s)
= 100 after 9 day(s)

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Description of key information

Readily biodegradable: 70.8-75.7% (CO2 evolution) in 28 days (OECD 301B)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Five studies investigating the biodegradability of OPP (CAS-No. 90-43-7) are available. Ready biodegradability was tested in four studies. The key study was carried out according to OECD guideline 301 B and GLP compliance. Using domestic sludge a biodegradation of 70.8 – 75.7% after 28 days was observed (Gonsior and Tryska, 1997).

The rapid biodegradation of OPP is supported by the results of the three other biodegradation studies. These studies were performed according to OECD guideline 301 F, and EU method C.4-D, respectively. In the test conducted according to OECD guideline 301 F 100% biodegradation was reached between 6 and 9 days (Kanne, 1989). In the test following the procedures of the EU method C.4-D, 96% biodegradation after 28 days was observed (Painter, 1985).

An inherent biodegradation study, which was performed according to OECD guideline 302 B shows a DOC removal of 100% after 10 days (Wellens, 1990).

Based on the results above it can be concluded that OPP is readily biodegradable.