4,4'-isopropylidenediphenol

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)

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Reference substance:

aniline

Parameter:

other: O2 consumption, TOC removal

Value:

89

Sampling time:

28 d

Details on results:

BIODEGRADATION OF BISPHENOL A AFTER 28 DAYS:
O2 consumption: 89%
TOC removal: 99%
Primary biodegradation (by HPLC): 100%

The 10 day window was met.

Based on the described results, BPA can be considered to be readily biodegradable.

Kinetic of test substance (in %):
= 0 after 0 day(s)
= 0 after 7 day(s)
= 62 ... 64 after 14 day(s)
= 75 ... 83 after 21 day(s)
= 85 ... 93 after 28 day(s)
Kinetic of control substance (in %):
= 60 after 7 day(s)
= 93 after 14 day(s)

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Executive summary:

Bisphenol A was found to be readily biodegradable in a OECD Guideline 301F Manometric Respirometry test. After 28 days, bisphenol A was biodegraded by 85 to 93% within the 10-day window.

Reference 2

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:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Duration of test (contact time):

28 d

Initial conc.:

25 mg/L

Based on:

test mat.

Initial conc.:

7 mg/L

Based on:

test mat.

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (O2 consumption)

Remarks:

O2 consumption, DOC removal, CO2 formation

Value:

>= 74.7 - <= 81.4

Sampling time:

28 d

Details on results:

TEMPERATURE CONTROL DURING TESTS I AND II:
The temperature of Test I was maintained at 27.1 +/- 0.6 deg.C, higher than the mandated 22 deg.C, due to a faulty temperature control in the incubator.

The temperature of Test II was maintained at 22.5 +/- 0.2 deg.C throughout the test.

The results show negligible differences in the extent of O2 consumption, CO2 evolution, and DOC removal at the two temperatures.

BIODEGRADATION OF BISHPENOL A:
Time to 10% degradation:
In the reaction mixtures with BPA, the time to 10% degradation (based on O2 consumption) was reached across all BPA reaction vessels by days 5.6 to 6.1 (Test I) and days 4.7 to 5.2 (Test II).

Time to 60% degradation:
The time to 60% degradation was reached by days 9.1 to 11.1 (Test I) and by days 7.2 to 8.7 (Test II).

O2 consumption:
The extent of O2 consumption reached 73.7 to 77.6 % (Test I) and 77.1 to 92.3% (Test II) at the end of the 10-day window.

Degradation at day 28 reached 74.7 to 81.4% at day 28 (Test I) and 78.2 to 81.0% (Test II).

Theoretical CO2 evolution:
Based on theoretical CO2 evolution, degradation at day 28 reached 75.9 to 76.2% at day 28 (Test I) and 76.3 to 81.2% (Test II).

Dissolved organic carbon (DOC) removal:
Based on DOC removal, degradation at day 28 reached 79.3 to 81.2% at day 28 (Test I) and 77.1 to 93.5% (Test II).

Control performance:
The vessels with benzoate reached the 10 day window by days 2.2 to 2.5 and reached 96.8 to 98.3% degradation at day 28, indicating that the microbes were performing properly.

In the toxicity controls, BPA at the concentrations used (7 or 25 mg/L) was non-toxic to the inoculum based on the degradation of benzoate reaching 92.2 to 96.8% by day 28.

Carbon dioxide was the only degradation product measured.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Bisphenol A was found to be readily biodegradable in an OECD Guideline 301F Manometric Respirometry test conducted following full Good Laboratory Practices.

Executive summary:

Bisphenol A was found to be readily biodegradable in an OECD Guideline 301F Manometric Respirometry test conducted following full Good Laboratory Practices. In Test II conducted at 22 °C, the extent of biodegradation reached 77.1 to 92.3% (Test II) at the end of the 10-day window based on O2 consumption and 76 to 81% of theoretical CO2 formation by day 28.

Description of key information

Bisphenol A is readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

Across a number of tests using international guidelines for measuring aerobic biodegradation under stringent test conditions, Bisphenol A is shown to be readily biodegradable.