Reaction mass of dodecyl acrylate and tridecyl acrylate

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

Study period:

from 2012-05-23 to 2012-06-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study according to guideline. Read across was performed with the mixture of CAS no. 2156-97-0 and 21643-42-5. Please refer to IUCLID section 13 for read across justification.

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

1992

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: Municipal waste water treatment plant Mannheim, Germany.
- Storage conditions: The inoculum was collected from the aeration tank of the plant and aerated in the laboratory until use. 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 96 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:

other: Total Organic Carbon (TOC)

Initial conc.:

26 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: according to guideline
- Solubilising agent (type and concentration if used): The amount of 66.2 mg test substance was added to a volumetric flask. After addition of about 800 mL demineralized water the mixture was stirred for about 3 hours and made up to the mark afterwards. The test substance was not completely dissolved, verified by visual inspection.
- Test temperature: 22 +/- 2°C
- pH adjusted: no
- Suspended solids concentration: 30 mg/L dry weight

TEST SYSTEM
- Culturing apparatus: 2 L incubtion bottles
- 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 TOC-analyzer equipped with an auto sampler (Shimadzu TOC-5000A).
- Test performed in closed vessels: yes
- Test performed in open system: no
- 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.

CONTROL AND BLANK SYSTEM
- 2 test substance assays
- 1 reference substance assay
- Inoculum blank: yes; 2 blank control assays.
- Inhibiton control: yes; 1 inhibition control test assay
- Toxicity control: yes

Reference substance:

aniline

Test performance:

The validity criteria were fulfilled.

Parameter:

% degradation (CO2 evolution)

Value:

80 - 90

Sampling time:

28 d

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

other information

Reason / purpose for cross-reference:

read-across source

Description of key information

No ready biodegradability study is available on the registered substance (Reaction mass of C12-C13 acrylates, EC Number 911-296-4). However, experimental data are available on an analogue substance (Reaction mass of C12-C14 acrylates, CAS 84238-60 -8).

In this experimental study conducted according to the OECD Test Guideline 301B (CO2 Evolution - modified Sturm test), a biodegradation level of 80-90% was reached within 28 days with the test item. All validity criteria were fulfilled. Thus, due to the proximity of the analogue substances, the registered substance is considered to be readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable