Reaction products of 4,4'-methylenebis(cyclohexylamine) and 2,2'-[(1-methylethylidene)bis(4,1-phenyleneoxymethylene)]bisoxirane

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 B (Ready Biodegradability: CO2 Evolution Test)

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The source of test organisms was activated sludge freshly obtained from a municipal sewage treatment
plant: Waterschap de Maaskant', 's-Hertogenbosch, the Netherlands.
The sludge was kept under continuous aeration until further treatment. The concentration of suspended
solids was 4.65 g/l in the concentrated sludge (information obtained from the municipal sewage
treatment plant). Before use, the sludge was allowed to settle (30-90 minutes) and the liquid decanted for
use as inoculum at the amount of 10 mVI of mineral medium.
The test has been accepted internationally (EEC, OECD) for determining the 'ready' biodegradability of test substances under aerobic conditions.

Duration of test (contact time):

28 d

Initial conc.:

16 mg/L

Based on:

test mat.

Initial conc.:

12 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Before weighing the test substance was heated to 40°C. PACM BADGE POLYMER ADDUCT is hardly soluble in water. Therefore, PACM BADGE POLYMER ADDUCT was weighed on a slide (A: 32.4; B: 31.1 and toxicity control: 31.9 mg) and quantitatively added to the test media. The test solutions were continuously stirred during the test.
Pre~arationo f bottles:
Pre-incubation medium
Type and number of
bottles
Preparation
Start of the incubation
The test substance was tested in duplicate at
31 -32 mg per 2 litres, corresponding to 12 mg TCA.
The carbon content was based on TC-analysis.
Mineral components, Milli-RO water (ca. 80% total
volume) and inoculum (1 % final volume) were added
to each bottle. This mixture was aerated with COa-free
air overnight to purge the system of C02.
Test suspension: containing test substance
and inoculum (2 bottles).
lnoculum blank: containing only inoculum (2 bottles)
Positive control: containing reference substance (ca.
40 mgA sodium acetate (Merck art. 1062680250,
batch TA 820068 033), TOC= 12 mgA) and inoculum
(1 bottle).
Toxicity control: containing test substance, reference
substance and inoculum (1 bottle).
The test substance and positive control were added to
the bottles.
The volumes of suspensions were made up to 2 litres
with Milli-RO water, resulting in the mineral medium
described before.
Three C02-absorbers (bottles filled with 100 ml 0.0125
M Ba(OH)2) were connected in series to the exit air
line of each test bottle.
The test was started by bubbling C02-free air through
the solution at a rate of approximately 1-2 bubbles per
second (ca. 30-1 00 mllmin).

Parameter:

% degradation (CO2 evolution)

Value:

0

Sampling time:

2 d

Parameter:

% degradation (CO2 evolution)

Value:

2

Sampling time:

5 d

Parameter:

% degradation (CO2 evolution)

Value:

3

Sampling time:

7 d

Parameter:

% degradation (CO2 evolution)

Value:

3

Sampling time:

9 d

Parameter:

% degradation (CO2 evolution)

Value:

4

Sampling time:

14 d

Parameter:

% degradation (CO2 evolution)

Value:

5

Sampling time:

19 d

Parameter:

% degradation (CO2 evolution)

Value:

8

Sampling time:

27 d

Parameter:

% degradation (CO2 evolution)

Value:

13

Sampling time:

29 d

Details on results:

The Total Carbon content (TC) of PACM BADGE POLYMER ADDUCT was determined to be
73.88%. Based on the TC content the Theoretical C02 production (ThC02) of PACM BADGE
POLYMER ADDUCT was calculated to be 2.71 mg C02/mg.
The concentration was 32.4 (A) and 31 .I mg (B) PACM BADGE POLYMER ADDUCT in 2 litres
test medium. Hence, the theoretical C02 production following complete degradation was 87.8
mg per 2 litres for A and 84.3 mg per 2 litres for B.
The positive control contained 81.0 mg sodium acetate (ThC02= 1.07 mg CO2/mg) resulting in a
theoretical C02 production following complete degradation of 86.7 mg per 2 litres.
The toxicity control contained 81.0 mg sodium acetate and 31.9 mg PACM BADGE POLYMER
ADDUCT in 2 litres of test medium. Hence, the theoretical C02 production following complete
degradation of PACM BADGE POLYMER ADDUCT plus sodium acetate was 173.1 mg per 2
litres.
The relative degradation values calculated from the measurements performed during the test
period revealed 17 and 10% degradation of PACM BADGE POLYMER ADDUCT for A and B
respectively. Thus, the criterion for ready biodegradability (at least 60% degradation within 28
days, reached within 10 days of biodegradation exceeding 10%) was not met.
In the toxicity control less than 25% degradation (20%) occurred in 14 days (based on ThC02).
Due to an increase in the degradation after day 14, the degradation in the toxicity control was
41 % after completion of the study.
Since the criterion for the toxicity control was not met, the test substance was assumed to be
inhibitory to micro-organisms in the study presently performed.
However, it is not likely that the outcome of this study, the criterion for ready biodegradability,
was influenced.
The temperature recorded in a vessel with water in the same room varied between 22 and
23°C.

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

PACM BADGE POLYMER ADDUCT was not readily biodegradable under the conditions of the modified Sturm test presently performed.

Executive summary:

PACM BADGE POLYMER ADDUCT was not readily biodegradable under the conditions of the modified Sturm test presently performed.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed