4,4'-Isopropylidenediphenol, oligomeric reaction products with 1-chloro-2,3-epoxypropane, reaction products with cyclohex-1,2-ylenediamine

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

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 D (Ready Biodegradability: Closed Bottle Test)

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The inoculum was prepared from a secondary effluent obtained from Peppers Ferry Wastewater Treatment Plant (Blacksburg, Virginia).

Duration of test (contact time):

28 d

Initial conc.:

28.8 mg/L

Based on:

test mat.

Initial conc.:

82 mg/L

Based on:

ThOD

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Apparatus
A standard constant-pressure respirometer was used to measure oxygen consumption. There were seven flasks as follows: two flasks contained inoculum (“Blank”); two flasks contained inoculum and test material (“Test”); one flask contained a reference substance and inoculum (“Ref”); one flask contained inoculum with test material and the reference substance (“Tox”); one flask contained test material and a sterilizing agent (“Sterile”).

A small open container of soda lime pellets in each flask removed evolved CO2 from the gas phase. Each flask was gently stirred continuously using a magnetic stirrer. Volume-change readings were made at least daily in the testing apparatus. Re-establishment of equilibrium was performed as needed. Gas volume changes in test and reference flasks were compared to volume changes in the blanks to determine net oxygen consumption in the test chambers.

Mineral Medium
Mineral medium was the growth medium and dilution water used for this study. It was prepared from four stock solutions in accordance with OECD 301F, using BMI deionized water and appropriate reagent grade compounds.

BMI deionized water was prepared by first dechlorinating Blacksburg, Virginia municipal water with activated carbon. The dechlorinated water was then deionized using mixed bed deionization tanks to a resistivity of > 1 megohm/cm, and polished with a Millipore Milli-Q UV Plus system with a 0.22-micron filter to a final resistivity of ≥ 18.1 megohm/cm.

Appropriate concentrations of mineral components (potassium and sodium phosphates plus ammonium chloride, calcium chloride, magnesium sulphate and iron (III) chloride) were added to BMI deionized water as specified in the OECD method (section 301A, paragraphs 5 and 6).

Test Environment
The test system was located in a secure area and was maintained at 22 ± 1 °C in near-darkness for the duration of the test.

Test Chronology
Testing proceeded as described in OECD 301F guidelines. Measurements of oxygen consumption were made daily. As oxygen consumption proceeded and/or atmospheric pressure changed, the cumulative volume change over those days was measured.

Re-establishment of equilibrium (reset) was performed at least daily, and more often when the extreme ranges of the graduated device were neared.

Reference substance:

acetic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

21.1

Sampling time:

10 d

Parameter:

% degradation (CO2 evolution)

Value:

21.2

Sampling time:

20 d

Parameter:

% degradation (CO2 evolution)

Value:

21.1

Sampling time:

28 d

Details on results:

The Diaminocyclohexane-Epon 828 Adduct 10-day window of degradation began at about Day 2 (~10% degradation) and ended at about Day 12 (~21.3% degradation). The product reached 21.1% degradation by test termination.
Some nitrification of Diaminocyclohexane-Epon 828 Adduct occurred. Nitrites were measured but not detected in any samples. All ThODs were calculated based on the occurrence of nitrification.

Results with reference substance:

Within expected range

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

The 4,4’-Isopropylidenediphenyl, oligomeric reaction products with 1-chloro-2,3-epoxypropane, reaction products with cyclohex-1,2 -ylenediamineid not reach pass levels for biodegradation within the 28-day period of the test, indicating that it is not readily biodegradable. The toxicity control treatment reached pass levels for biodegradation by day 7, indicating that the test substance is not inhibitory.

Executive summary:

The 4,4’-Isopropylidenediphenyl, oligomeric reaction products with 1-chloro-2,3-epoxypropane, reaction products with cyclohex-1,2 -ylenediamineid not reach pass levels for biodegradation within the 28-day period of the test, indicating that it is not readily biodegradable. The toxicity control treatment reached pass levels for biodegradation by day 7, indicating that the test substance is not inhibitory.

Description of key information

The 4,4’-Isopropylidenediphenyl, oligomeric reaction products with 1-chloro-2,3-epoxypropane, reaction products with cyclohex-1,2 -ylenediamineid not reach pass levels for biodegradation within the 28-day period of the test, indicating that it is not readily biodegradable. The toxicity control treatment reached pass levels for biodegradation by day 7, indicating that the test substance is not inhibitory.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed