Reaction mass of trimethylolpropane triacrylate and hexamethyleneimine

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

Study period:

22 March 2018 - 26 July2018

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

17 July 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Identification: Photomer 4250
Appearance: Colourless to pale yellow liquid
Batch: 17C13003
Purity/Composition: Not indicated
Test item storage: At room temperature protected from light
Stable under storage conditions until:14 September 2018 (expiry date)

Additional information
Test Facility test item number:209236/A
Purity/Composition correction factor: No correction factor required
Test item handling: No specific handling conditions required
CAS number: 73003-78-8

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Source:
The source of test organisms was activated sludge freshly obtained from a municipal sewage treatment plant: 'Waterschap Aa en Maas', 's-Hertogenbosch, The Netherlands, receiving predominantly domestic sewage.

Treatment:
The freshly obtained sludge was kept under continuous aeration until further treatment. Before use, the sludge was coarsely sieved (1 mm). After treatment the concentration of suspended solids (SS) was determined to be 3 g/L in the concentrated sludge as used for the test. The magnetically stirred sludge was used as inoculum at the amount of 3 mL per litre of mineral medium, leading to a SS concentration of 8 mg/L.

Duration of test (contact time):

14 d

Initial conc.:

19 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Reference substance:

other: Sodium acetate

Parameter:

% degradation (CO2 evolution)

Value:

69

Sampling time:

29 d

Parameter:

% degradation (CO2 evolution)

Value:

66

Sampling time:

29 d

Details on results:

Theoretical CO2 Production
The ThCO2 of Photomer 4250 was calculated to be 2.34 mg CO2/mg.
The ThCO2 of sodium acetate was calculated to be 1.07 mg CO2/mg.

Biodegradation
Biodegradation of Photomer 4250 and Sodium Acetate in the Modified Sturm Test
The relative biodegradation values calculated from the measurements performed during the test period revealed 69% and 66% biodegradation of Photomer 4250, for A vessel and B, respectively (based on ThCO2).
However, average biodegradation of Photomer 4250 in vessel A and B did not reach ≥60% within a 10-day window. Thus, the criterion for ready biodegradability was not met.
In the toxicity control, more than 25% biodegradation occurred within 14 days (58%, based on ThCO2). Therefore, the test item was assumed not to inhibit microbial activity.
Functioning of the test system was checked by testing the reference item sodium acetate, which showed a normal biodegradation curve

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

In conclusion, Photomer 4250 was not readily biodegradable under the conditions of the modified Sturm test presently performed. However, since the results of the present test indicate that the pass level criterion was fulfilled but the 10-day window criterion was not fulfilled, the results can be used to indicate inherent biodegradability.
 

Executive summary:

The objective of the study was to evaluate the test item Photomer 4250 for its ready biodegradability in an aerobic aqueous medium with microbial activity introduced by inoculation with activated sludge.

The study procedures described in this report were in compliance with the OECD guideline No. 301 B, 1992. In addition, the procedures were designed to meet the test methods of the ISO standard 10634, 1995.

Photomer 4250 was a colourless to pale yellow liquid. The test item was tested in duplicate at a target concentration of 19 mg/L, corresponding to 12 mg TOC/L. The organic carbon content was based on the molecular formula. The Theoretical CO2 production (ThCO2) of Photomer 4250 was calculated to be 2.34 mg CO2/mg.

The study consisted of six bottles:

•       2 inoculum blanks (no test item),

•       2 test bottles (Photomer 4250),

•       1 procedure control (sodium acetate) and

•       1 toxicity control (Photomer 4250 plus sodium acetate).

Since Photomer 4250 was not sufficiently soluble to allow preparation of an aqueous solution at a concentration of 1 g/L, weighed amounts were added to the 2 litre test bottles containing medium with microbial organisms and mineral components. To this end, small watch glasses were used to transfer the weighed amounts of test item to the respective test bottles. The test solutions were continuously stirred during the test to ensure optimal contact between the test item and test organisms. Test duration was 28 days for the inoculum blank and test item (last CO2 measurement on day 29) and 14 days for the procedure and toxicity control (last CO2 measurement on day 15).

The relative biodegradation values calculated from the measurements performed during the test period revealed 69% and 66% biodegradation of Photomer 4250, for A vessel and B, respectively (based on ThCO2).

However, average biodegradation of Photomer 4250 in vessel A and B did not reach ≥60% within a 10-day window. Thus, the criterion for ready biodegradability was not met.

In the toxicity control, Photomer 4250 was found not to inhibit microbial activity.

Since all criteria for acceptability of the test were met, this study was considered to be valid.

In conclusion, Photomer 4250 was not readily biodegradable under the conditions of the modified Sturm test presently performed. However, since the results of the present test indicate that the pass level criterion was fulfilled but the 10-day window criterion was not fulfilled, the results can be used to indicate inherent biodegradability.

Description of key information

Study conducted to recognised testing guidelines with GLP certification

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable

Type of water:

freshwater