2,3-dihydroxypropyl methacrylate

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): Municipal activated sludge from the wastewater treatment plant of Mannheim, Germany.
- Storage conditions: The inoculum was collected on 06 July 2016 from the aeration tank of the plant. A suitable aliquot of the activated sludge suspension was sieved by a finely woven mesh with a mesh size about 1 mm. To reduce the content of inorganic carbon in the blank controls, the activated sludge was aerated with carbon dioxide free air for about 24 hours at 22 ± 2° C.
- Preparation of inoculum for exposure: At the day of exposure the suspension was washed one time with drinking water. Therefore the aeration was stopped and the sludge was allowed to settle. After settling the supernatant was discarded and the remaining sludge suspension was filled up with drinking water and the concentration oft the sludge was adjusted to 6.0 g/L dry weight.
- Pretreatment: none
- Concentration of sludge: Aliquots of 7.5 mL were added to the test vessels to obtain an activated sludge concentration of 30 mg/L dry weight.

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

TOC

Remarks:

approx. 38 mg/L test substance

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline
- Test temperature: 22 +/- 2°C
- pH: 7.4 +/- 0.2
- pH adjusted: yes
- Suspended solids concentration: 30 mg/L dry weight

TEST SYSTEM
- Culturing apparatus: 2 L incubation vessels
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: aeration with carbon dioxide free air
- Measuring equipment: The TIC- and DOC-analyses were performed as repeat determination, using a TOCanalyzer equipped with an auto sampler (Shimadzu TOC-5000A and/or TOC-L, or TOCCSN).
- Test performed in open system: yes
- Details of trap for CO2 and volatile organics if used: The bottles were connected to two serial scrubbing bottles (total volume 250 mL) filled with 100 mL 0.05 mol sodium hydroxide solution for the adsorption of carbon dioxide from biodegradation processes. Usually twice a week the Total Inorganic Carbon (TIC) values of the adsorption solutions of the first trap were determined and used for the calculation of the produced carbon dioxide. After each sampling the second trap was moved forward and the new trap with fresh sodium hydroxide solution was placed into the second position. Each trap was analyzed separately.

SAMPLING
- Sampling frequency: 3-7 days

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

Reference substance:

aniline

Parameter:

% degradation (CO2 evolution)

Value:

80 - 90

Sampling time:

28 d

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The conclusion that Glycerol Monomethacrylate (GMMA) was readily biodegradable in this carbon dioxide evolution test based on the quantitative determination of the formed carbon dioxide in the test substance assays by comparison with the calculated maximal theoretical carbon dioxide production. The required pass level for ready biodegradability within a ten day window was reached.
The degree of biodegradation at the end of the ten day window was approx. 73 % CO2/ThCO2.
The degree of biodegradation after an exposure period of 28 days was 80-90 % CO2/ThCO2 in this test.
The degree of biodegradation was calculated as mean of the values from two test assays at the end of exposure.
The results in this study are consistent with all validity criteria and the test is valid according to the test guideline of this study. No deviations from the test guidelines or other incidents occurred during the course of the reported test, which may have influenced the results.

Executive summary:

Glycerol Monomethacrylate (GMMA) was tested for ready biodegradability in the Carbon Dioxide Evolution Test (OECD 301B). The test concentration was 20 mg/ L TOC nominal, equiv. to approx 38 mg/ test substance. Activated sludge from a minicipal sewage plant (municipal waste water treatment plant Mannheim, Germany). Degree of biodegradation 80-90 % CO2/ThCO2 after an exposure period of 28 days. The degree of biodegradation at the end of the ten day window was approx. 73 % CO2/ThCO2. Glycerol Monomethacrylate (GMMA) was readily biodegradable under the conditions of this test.

Description of key information

Glycerol Monomethacrylate (GMMA) was tested for ready biodegradability in the Carbon Dioxide Evolution Test (OECD 301B). The test concentration was 20 mg/ L TOC nominal, equiv. to approx 38 mg/ test substance. Activated sludge from a minicipal sewage plant (municipal waste water treatment plant Mannheim, Germany). Degree of biodegradation 80-90 % CO2/ThCO2 after an exposure period of 28 days. The degree of biodegradation at the end of the ten day window was approx. 73 % CO2/ThCO2. Glycerol Monomethacrylate (GMMA) was readily biodegradable under the conditions of this test.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable