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Biodegradation in water: screening tests

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Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2010-11-30 - 2011-02-18
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study OECD 310, GLP.
Qualifier:
according to guideline
Guideline:
OECD Guideline 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)
Version / remarks:
(2006), EN ISO 14593 (1999)
Deviations:
no
GLP compliance:
yes (incl. QA statement)
Oxygen conditions:
aerobic
Inoculum or test system:
sewage, predominantly domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure):
Muncipal sewage treatment plant, D-31137 Hildesheim
The activated sludge was washed twice with autoclaved tap water. After the second washing the settled sludge was resuspended in mineral salts medium and was maintained in an aerobic condition by aeration for 4 hrs. therafter it was homogenized with a blender. The supernatant was decanted and was mainbtained in an aerobic condition by aeration withb CO2 free air for 6 days. 10 ml/l were used to initiate inoculation.

Colony forming units in the test solution: 10 (exp5) to 10 (exp8) CFU/l
Duration of test (contact time):
28 d
Initial conc.:
25 mg/L
Based on:
test mat.
Initial conc.:
18.6 mg/L
Based on:
ThIC
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:

TEST METHOD

Duration 28 days
Application Once at test start, the test item (2.3 µL/test vessel) was injected directly into the test solution.
Headspace to liquid ratio 1:2
Test vessels / volume Headspace flasks / 120 mL
Test medium / volume Mineral salts medium acc. to OECD 310 / 80 mL
Agitation Shaker
Day 0 - 1: 120 rpm
Day 1 - 14: 130 rpm
Day 14 - 28: 120 rpm
Temperature 21 - 23 °C
Photoperiod Low light conditions

CHRONOLOGICAL TEST DESCRIPTION

The following incubation vessels were prepared for each sampling date (except test end):

- three for the test item concentration (P1, P2, P3)
- three for the functional control (R1, R2, R3)
- three for the toxicity control (T1, T2, T3)
- three for the inoculum control (C1, C2, C3)

To calculate the 95 % confidence interval for the mean percentage biodegradation, 5 replicates of test item, reference item, toxicity control and inoculum control were set up for test end.

The test medium, consisting of the required volumes of mineral medium stock solutions and inoculum in demineralised water, was prepared in a measuring flask. 80 mL test medium were placed in each test vessel of the inoculum control and test item replicates.

The reference item was weighed out and was transferred into a measuring flask with demineralised water. The required volumes of mineral medium stock solutions and inoculum were added and the flask was filled up with demineralised water. 80 mL of this solution were placed in each test vessel of the reference item and toxicity control replicates.

2.3 µL test item was injected directly into the solution (below the surface) of each test item and toxicity control replicate.

The CO2 production in the test vessels was determined by measuring the increase of the inorganic carbon (IC) concentration during the incubation.

Sodium hydroxide solution (0.74 mL 7 mol/L solution to 80 mL medium) was injected to each vessel sampled. The vessels were shaken on an overhead shaker (100 rpm) for 1 h at test temperature. Suitable volumes of the liquid phase were analysed.

VALIDITY CRITERIA

The percentage degradation of the reference item must exceed the pass level of 60 % by day 14.
The mean amount of TIC present in the inoculum controls (C1 - C5) at the end of the test is < 3 mg C/L.

EVALUATION

The amount of TIC produced was calculated by correcting the results of the test item and reference item for endogenous TIC production of the control groups and the blind value of the sodium hydroxide solution.

The biodegradation was calculated from the ratio theoretical TIC concentration at test start (ThIC = TOC) to net TIC production.

TIC = (mg C in the liquid + mg C in the headspace)
= (VL x CL) + (VH x CH)

VL = volume of liquid in the bottle (litre)
CL = concentration of IC in the liquid (mg/L as carbon)
VH = volume of the headspace (litre)
CH = concentration of IC in the headspace (mg/L as carbon)

%D = biodegradation (%)
TICt = mg TIC produced in test bottle at time t
TICb = mean mg TIC produced in control bottles at time t
TOC = mg TOC added initially to the test vessel

The mean amount of total inorganic carbon (TIC) produced in the inoculum controls at the end of the test should be < 15 % of the organic carbon added initially as the test item.

The 95 % confidence interval for the mean percentage biodegradation after 28 days was calculated using software SigmaPlot.

Software Excel, MICROSOFT CORPORATION
SigmaPlot (Windows), SPSS CORPORATION



Reference substance:
benzoic acid, sodium salt
Remarks:
as functional control
Parameter:
% degradation (CO2 evolution)
Value:
62
Sampling time:
28 d
Remarks on result:
other: The 95% confidence interval on day 28 was 50 - 74 %
Parameter:
% degradation (CO2 evolution)
Value:
2
Sampling time:
3 d
Parameter:
% degradation (CO2 evolution)
Value:
27
Sampling time:
6 d
Parameter:
% degradation (CO2 evolution)
Value:
42
Sampling time:
14 d
Details on results:
Degradation products: not measured
Results with reference substance:
71 % after 3d
80 % after 8d
88 % after 22 d
90 % after 28 d

The adaptation phase of the functional control changed after 1 day into the degradation phase (degradation  10 %). The course of the degradation phase was rapid and the pass level of 60 % was reached after 3 days. The biodegradation came to 90 % after 28 days. The validity criterion degradation > 60 % after 14 d is fulfilled. The 95 % confidence interval on day 28 was 87 - 93 %.

The biodegradation of the toxicity control reached 66 % within 14 days and it came to 68 % after 28 days. The biodegradation of the reference item was not inhibited by the test item in the toxicity control. The 95 % confidence interval on day 28 was 64 - 72 %.

The criteria of validity of the test have been met:

- The percentage of degradation of the reference substance in the control series is greater than 60% in 14 days;

- The mean amount of TIC (total inorganic carbon) produced in the inoculum controls at the end of the test was 1.83 mg C/L (validity criterion:

TIC < 3 mg C/L).

The Degradation of the reference substance has not been inhibited by the presence of the test substance.

Validity criteria fulfilled:
yes
Remarks:
according to the guideline
Interpretation of results:
readily biodegradable, but failing 10-day window
Conclusions:
In a fully valid guideline study with GLP (OECD 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)), 62 % (95% confidence interval on day 28 was 50 - 74%) biodegradation was obtained after 28 days. Therefore, Isodecyl methacrylate is classified as readily biodegradable.
However, the 10-day criterion for ready biodegradability was not met.


Executive summary:

In an OECD 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace) test, the percentage of biodegradation of Isodecyl methacrylate was 62 % after 28 days (95% confidence interval on day 28 was 50 - 74%; end of trial).

The substance showed no inhibitory effect against micro-organisms. The 10 % level (beginning of biodegradation) was reached after 4 days and the pass level of 60 % after 19 days. The biodegradation of the test item reached a maximum of 73 % on day 22. On day 28 the mean biodegradation was 62 %, the 95 % confidence interval was 50 - 74 % The test item is classified as readily biodegradable after 28 days but without complying the 10 day window.

NOTE:Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
supporting study
Study period:
07.09.1988 - 05.10.1988
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study, GLP. COMMENTS: > = 60 % biodegradation within 10 d
Principles of method if other than guideline:
Method: Degradation - biotic degradation: modified MITI test, EEC Dir. 84/449, published in: Official Journal of the European Communities, No. L251/199
GLP compliance:
yes
Oxygen conditions:
aerobic
Inoculum or test system:
other: activated sludge (mixture of 2 storage lakes, 3 municipal sewage plants and 1 industrial sewage plant
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): MITI-test
Inoculum:
Sludge sampling sites were: Rivers: Rhine (south of Düsseldor f, port Ruhrort ) , Lenne ( Schmallenberg)
Lakes: storage lakes (Bigge and Henne)
Municipal sewage plants: Essen (south), Maumke, Nordenau
Industrial sewage plant: Dusseldorf, south (Henkel)
From the rivers and lakes one litre each of surface water and surface soil of the beach which were in contact with the atmosphere were withdrawn.
From each sewage treatment plant one litre of recycled sewage was withdrawn.

Date of sampling: 5th September 1988

Preparation of the inoculum:
The sludge samples collected from the sampling sites were mixed by stirring in a single container. The soil samples were shaken for one hour with distilled water, and the supernatant was mixed with the sludge samples. The mixture settled. The floating foreign matter was removed and the
supernatant was filtered with No. 2 filter paper. The filtrate was adjusted to pH 7.0 ± l .0 with sodium hydroxide or phosphoric acid, transferred
into a culture tank and aerated.

Inoculum without adaptation
Aliquots were withdrawn from the combked samples (soil and sewage sludge; see Preparation of inoculum), centrifuged and diluted to
provide sufficient volume for a 1 % inoculum for each test vessel (corresponding to 30 mg dry matter/l test medium).
Duration of test (contact time):
28 d
Initial conc.:
100 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
O2 consumption
Details on study design:
Test temperature: 22 °C
Reference substance:
aniline
Parameter:
% degradation (O2 consumption)
Value:
12.8
Sampling time:
5 d
Parameter:
% degradation (O2 consumption)
Value:
59.2
Sampling time:
10 d
Parameter:
% degradation (O2 consumption)
Value:
62.2
Sampling time:
11 d
Parameter:
% degradation (O2 consumption)
Value:
76.6
Sampling time:
28 d
Details on results:
After a lag-phase of less than 19.5 hours oxygen consumption took place. The samples containing pepton and test substance showed a higher oxygen uptake than the samples containing only pepton. The consumption rates increased with increasing concentration of the test substance. This indicates that the test substance causes no inhibition but can be used as energy source additionally to pepton.
Results with reference substance:
65.6 % degradation after 7 days
84.0 % degradation after 28 days
Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
Methacrylic acid ester 13.6 is regarded as readily biodegradable based upon a study according to EEC Directive 84/449/EEC, Degradation – biodegradation, Modified MITI Test. 76.6 % biodegradation within 28 days.
Executive summary:

The ready biodegradation of Methacrylic acid ester 13.6 was investigated in a study conducted according to EEC Directive 84/449/EEC, Degradation – biodegradation, Modified MITI Test, published in official Journal of the European Communities No. L251/199) over a period of 28 days usingsludge samples from different places like rivers, lakes, municipal and industrial sewage plants as inoculum. The biodegradation rate was determined by measurement of O2 consumption. Inoculum blank and procedural / functional control with the reference substance aniline were performed.

After 28 days the degradation of Methacrylic acid ester 13.6 reached 76.6 %.The functional control reached the pass level 84.0 % after 28 d.

This study is regarded as reliable without restriction and satisfies the guideline requirements for ready biodegradation. Methacrylic acid ester 13.6 proved to be readily biodegradable.

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
supporting study
Study period:
1999
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study OECD 301 B (modified Sturm test), GLP. COMMENTS: > = 60 % biodegradation within 10 d
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Version / remarks:
17th July 1992
GLP compliance:
yes
Oxygen conditions:
aerobic
Inoculum or test system:
sewage, predominantly domestic, non-adapted
Details on inoculum:
- Source of inoculum/activated sludge: sewage sludge, from the water treatment plant Emeraude (SIARR), F-76141 Petit-Quevilly, France

- Preparation of inoculum for exposure: initially sieving sewage sludge and centrifuging three times for at least 5 min. for each centrifugation, the supernatant was rejected and the pellet was redispersed in mineral medium
- Preconditioning: air was bubbled through for 7 days, the temerature was 22 °C ± 2 °C
-Mineral medium: prepared according to OECD and EEC recvommendations


Duration of test (contact time):
28 d
Initial conc.:
10 mg/L
Based on:
other: TOC
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
The test substance was dispersed in reconstituted water (OECD mineral medium) prepared from deionised water with a conductivity < 10 µS/cm.
CO2 scrubbed air was bubbeled through the flasks over the test period.
- pH: 7.53 - 8.50
- temperature: 20 °C - 24 °C
Reference substance:
other: sodium acetate
Parameter:
% degradation (CO2 evolution)
Value:
> 100
Sampling time:
28 d
Parameter:
% degradation (CO2 evolution)
Value:
98.36
Sampling time:
21 d
Parameter:
% degradation (CO2 evolution)
Value:
73.88
Sampling time:
12 d
Parameter:
% degradation (CO2 evolution)
Value:
29.72
Sampling time:
5 d
Results with reference substance:
Control substance: sodium acetate
Kinetic: 8 days: 38.22 % degradation
14 days: 62.44 % degradation
28 days: 94.26 % degradation
Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
Under the experimental conditions, Methacrylic acid ester C12-C16 linear and branched (LIMA) is readily biodegradable in the 28-d modified Sturm test according to OECD 301 B.
There was > = 60 % biodegradation within 10 days.
Executive summary:

Under the experimental conditions, Methacrylic acid ester C12-C16 linear and branched (LIMA) is readily biodegradable in the 28-d modified Sturm test according to OECD 301 B. The 10-day window was achieved.

At the end of the 10-day window on the 12th day the biodegradation of the test substance was 74% and according to Commission Directive 93/21/EEC and OECD guideline No. 301B, the value of 60% has to be reached in this 10-day window within 28 days in order to classify the test substance as readily biodegradable. Based on this Directive, Methacrylic acid ester C12-C16 linear and branched (LIMA) is therefore readily biodegradable in the 28-day modified Sturm test under these experimental conditions. However, the biodegradation rate was > 100 % for Methacrylic acid ester C12-C16 linear and branched (LIMA) after 28 days.

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
22 April - 20 May 2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study OECD 301 B, non GLP. Study performed and documented equivalent to GLP standards. Study according to relevant guideline.
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)
Version / remarks:
(adopted 17 July 1992)
Deviations:
no
Principles of method if other than guideline:
In this method, a low concentration of bacterial inoculum (30 mg/L of suspended solids) derived from the activated sludge of a sewage treatment
plant, mineral nutrients and the test material as the sole source of organic carbon were incubated together in a closed glass vessel placed on a
magnetic stirrer under controlled conditions.
The degradation of the test material was monitored by the evolution of carbon dioxide. The measurements were taken at frequent time intervals over a period of 28 days. The amount of carbon dioxide produced by the microbial population during biodegradation of the test substance (corrected for
the value in the blank control) was expressed as percentage of the theoretical value (ThC02) or the DOC and served as the measure for the extent of
biodegradation. Additionally, ultimate biodegradation was determined by analysis of dissolved organic carbon (DOC) at the beginning and at the end of the test.
GLP compliance:
no
Remarks:
Study performed and documented equivalent to GLP standards.
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): Activated sludge from the aeration tank
of a municipal waste water treatment plant, not adapted, not preconditioned
Duration of test (contact time):
28 d
Initial conc.:
ca. 20 mg/L
Based on:
DOC
Parameter followed for biodegradation estimation:
CO2 evolution
Details on study design:
TEST CONDITIONS
- Composition of medium: Aerobic mineral salts medium (see table 1) prepared with deionised water (conductivity: <1.5 μS/cm; DOC: ~ 0.3 mg/L)

Table 1:
Composition of the mineral salts medium.

Stock solution I 10 ml/l Ammonium chloride, NH4CI 0.50 g
(pH 7.4) Di-sodium hydrogenphosphate, Na2HP04 x 2 H20 33.40 g
Potassium dihydrogenphosphate, KH2P04 8.50 g
Di-potassium monohydrogenphosphate, K2HP04 21.75 g
Stock solution II 1 ml/l Calcium chloride, anhydrous, CaCl2 27.50 g
Stock solution Ill 1 ml/l Magnesium sulfate, MgS04 x 7 H20 22.50 g
Stock solution IV 1 ml/l Iron (Ill) chloride, FeC13 x 6 H20 0.25 g

- Test temperature: 22 ±0.5 °C
- pH: 7.4 (±0.2)
- pH adjusted: yes
- Aeration of dilution water: yes, with synthetic CO2-free air
- Suspended solids concentration: 30 mg/l
- Continuous darkness: yes
- Feed: No feed, Methacrylic acid ester 17.4 as sole organic carbon source
- Test substance concentration (as TOC): 10 - 20 mg/l
- Control of sensitivity: Functional control with 20 mg/l sodium benzoate (as TOC)

TEST SYSTEM
- Culturing apparatus: 2500 ml glass bottles
- Number of culture flasks/concentration: For each test series the following number of test flasks was set up:
T: Test suspension containing inoculum, test medium and test substance (two replicates)
B: lnoculum blank containing inoculum and test medium (two replicates)
R: Procedure control containing inoculum, test medium and sodium benzoate as ready biodegradable reference compound (one replicate)

- Measuring equipment: Dissolved organic carbon (DOC) was determined in duplicate with a Shimadzu 5000A TOC-Analyzer using the NPOC-mode.
For each determination 3 single injections were performed. The samples from the individual test vessels were centrifuged (15 min at 4500 g) and
acidified to pH <2. Prior to analysis the samples were sparged with GO2-free high purity air for 10 min to remove inorganic carbon.
Inorganic carbon (IC) was determined in the same way as DOC without sparging the samples before analysis.
- Details of trap for CO2 and volatile organics if used: gas absorption bottles filled with NaOH

SAMPLING
- Sampling frequency: frequent intervals to allow the assessment of the 10-d window


CONTROL AND BLANK SYSTEM
- Inoculum blank: lnoculum blank containing inoculum and test medium (two replicates)
- Abiotic sterile control: not conducted
- Toxicity control: not conducted
Reference substance:
benzoic acid, sodium salt
Parameter:
% degradation (CO2 evolution)
Value:
97
Sampling time:
28 d
Remarks on result:
other: the test substance reached 80% degradation at the end of the 10-d window
Results with reference substance:
The positive control, sodium benzoate, reached 99% biodegradation after 14 days.
Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
Methacrylic acid ester 17.4 reached the pass level of 60% for ready biodegradability in the C02 Evolution Test within the 10-d window and, therefore,
can be termed as readily biodegradable.
Executive summary:

The biodegradability of Methacrylic acid ester 17.4 exposed to microorganisms derived from the activated sludge of a municipal sewage treatment plant was investigated under aerobic static exposure conditions.

The biodegradability - based on CO2, evolution - of Methacrylic acid ester 17.4 was calculated to be 97% of the theoretical value (ThC02) after an incubation time of 28 days.

The biodegradation of Methacrylic acid ester 17.4 reached 80% at the end of the 10-d window.

Significant biodegradation of the test substance was observed after a lag phase of about 4 days.

The positive control, sodium benzoate, reached 99% biodegradation after 14 days, thus confirming suitability of inoculum and test conditions.

The respective DOC concentrations at the beginning (theoretical values) and at the end of the test (after 28 days) were (in mg/l):

20.0 and 1.03 for the test units (mean of two replicates)

<0.5 and 0.79 for the inoculum blank (one replicate)

20.1 and 0.93 for the procedure control (mean of two replicates)

The calculated biodegradation based on DOC measurement reached 99% for Methacrylic acid ester 17.4 and 99% for sodium benzoate. The data show that the test compound was almost completely mineralized, since the determined degradation values based on C02 evolution were similar to those based on DOC.

Methacrylic acid ester 17.4 reached the pass level of 60% for ready biodegradability in the C02 Evolution Test within the 10-d window and, therefore, can be termed as readily biodegradable.

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
experimental study
Adequacy of study:
key study
Study period:
7. September 1988 - 5. October 1988
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study, GLP. COMMENTS: > = 60 % biodegradation within 10 d
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
Deviations:
no
Principles of method if other than guideline:
Degradation - biotic degradation: modified MITI test, EEC Dir. 84/449, published in: Official Journal of the European Communities, No. L251/199
The biodegradation test was performed as a respirometric test by using a "Sapromat". The inoculated medium with the test substance which was
the only carbon source was stirred in closed flasks at 20 +/- 3 °C in the dark. The oxygen consumption was determined by measuring the quantity of oxygen required to maintain a constant pressure in the apparatus. Evolved C02 was adsorbed by granular soda lime containing an indicator.
The biodegradation was calculated according to the following equation:
(BOD - B)
Percentage degradation = -------------------------- x 100
ThOD (or COD)
BOD = biochemical oxygen demand of the test compound (experimental; in mg) measured on the BOD curve,
B = oxygen consumption of basal culture medium to which the inoculum is added (experimental: in mg) measured on the BOD curve,
ThOD = theoretical oxygen demand required when the test compound is completely oxidized (theoretical; in mg),
COD = chemical oxygen demand (experimental: in mg)

The degradation was followed over a period of 28 days. It was recorded as a continuous curve.
Finally, the biodegradation of the test compound was expressed as the percentage of the theoretical oxygen demand.
GLP compliance:
yes
Oxygen conditions:
aerobic
Inoculum or test system:
other: activated sludge (mixture of 2 storage lakes, 3 municipal sewage plants and 1 industrial sewage plant)
Details on inoculum:
- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure): MITI-test
Inoculum:
Sludge sampling sites were: Rivers: Rhine (south of Düsseldor f, port Ruhrort ) , Lenne ( Schmallenberg)
Lakes: storage lakes (Bigge and Henne)
Municipal sewage plants: Essen (south), Maumke, Nordenau
Industrial sewage plant: Dusseldorf, south (Henkel)
From the rivers and lakes one litre each of surface water and surface soil of the beach which were in contact with the atmosphere were withdrawn.
From each sewage treatment plant one litre of recycled sewage was withdrawn.

Date of sampling: 5th September 1988

Preparation of the inoculum:
The sludge samples collected from the sampling sites were mixed by stirring in a single container. The soil samples were shaken for one hour with distilled water, and the supernatant was mixed with the sludge samples. The mixture settled. The floating foreign matter was removed and the
supernatant was filtered with No. 2 filter paper. The filtrate was adjusted to pH 7.0 ± l .0 with sodium hydroxide or phosphoric acid, transferred
into a culture tank and aerated.

Inoculum without adaptation
Aliquots were withdrawn from the combked samples (soil and sewage sludge; see Preparation of inoculum), centrifuged and diluted to
provide sufficient volume for a 1 % inoculum for each test vessel (corresponding to 30 mg dry matter/l test medium).
Duration of test (contact time):
28 d
Initial conc.:
100 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
O2 consumption
Reference substance:
aniline
Preliminary study:
Preliminary Test:
A preliminary test was performed to determine whether the inoculum was inhibited by the usually used concentration of the test substances in the
Miti-test (100 mg/l).
Inoculum:
Source: Samples of activated sludge were withdrawn from a sewage plant mainly fed with municipal sewage.
Pretreatment:
The amount of solids was calculated and the wet sludge suspended with Ringer's solution to yield a concentration of 3 g suspended solids per litre.
Test procedure:
For the performance of the test 4 test vessels were prepared:
Vessel 1 and 2 (control): basal culture medium + peptone (50 mg/l)
Vessel 3: basal culture medium + peptone (50 mg/l) + test chemical (100 mg/l)
Vessel 4 : basal culture medium + peptone (50 mg/l) + test chemical ( 50 mg/l)
The vessels were closed and placed in the "Sapromat". After equalization of temperature and pressure (30 min) the culture vessels and
corresponding pressure controller were connected.
During the following test period (6 days) the oxygen consumption was recorded automatically.
Test performance:
Test procedure:
For the performance of the test 8 test vessels were prepared: Vessel 1 and 2: deionized water + test chemical (100 mg/l)
Vessel 3 and 4: basal culture medium + test chemical (100 mg/l) + inoculum (30 mg
dry matter/l)
Vessel 5 and 6: basal culture medium + reference substance (100 mg/l) + inoculum
(30 mg dry matter/l)
Vessel 7 and 8: basal culture medium + inoculum (30 mg dry matter/l)
The substances were added directly to the vessels. The vessels were closed and placed in the "Sapromat". After equalization of temperature and
pressure the culture vessels and corresponding pressure controller were connected. During the following test period the oxygen consumption was
recorded automatically.
Type of analysis:
For the determination of the oxygen consumption, a respirometer was used to maintain the pressure constant ("Sapromat", Voith, Heidenheim). The
consumed oxygen was recorded as BOD/l.

Temperature control during the test:
The test vessels were placed in the temperature controlled water bath of the Sapromat. The temperature was 22 °C.
Parameter:
% degradation (O2 consumption)
Value:
ca. 7.5
Sampling time:
2 d
Parameter:
% degradation (O2 consumption)
Value:
ca. 21
Sampling time:
3 d
Parameter:
% degradation (O2 consumption)
Value:
ca. 60
Sampling time:
10 d
Parameter:
% degradation (O2 consumption)
Value:
ca. 72
Sampling time:
15 d
Parameter:
% degradation (O2 consumption)
Value:
ca. 88.5
Sampling time:
28 d
Details on results:
After a lag-phase of less than 19.5 hours oxygen consumption took place. The samples containing pepton and test substance showed a higher
oxygen uptake than the samples containing only pepton. The consumption rates increased with increasing concentration of the test substance. This
indicates that the test substance causes no inhibition but can be used as energy source additionally to pepton.
Miti-Test:
Percent biodegradation of the test substance: The final biodegradation was 88.5%.
Results with reference substance:
Final biodegradation: 93.8 %
Validity criteria fulfilled:
yes
Remarks:
10 day window criteria was fulfilled
Interpretation of results:
readily biodegradable
Conclusions:
Dodecyl methacrylate is regarded as readily biodegradable based upon a study according to EEC Directive 84/449/EEC, Degradation – biodegradation, Modified MITI Test (OECD 301 C). 88.5 % biodegradation within 28 days. There was > = 60 % biodegradation within 10 days.
Executive summary:

The ready biodegradation of dodecyl methacrylate was investigated in a study conducted according to EEC Directive 84/449/EEC, Degradation – biodegradation, Modified MITI Test, published in official Journal of the European Communities No. L251/199) over a period of 28 days using sludge samples from different places like rivers, lakes, municipal and industrial sewage plants as inoculum. The biodegradation rate was determined by measurement of O2 consumption. Inoculum blank and procedural/functional control with the reference substance aniline was performed.

After 28 days the degradation of Dodecyl methacrylate reached 88.5 %.The functional control reached the pass level 93.8% after 28 d. 60 % degradation was found after 10 days.

This study is regarded as reliable without restriction and satisfies the guideline requirements for ready biodegradation.Dodecyl methacrylate proved to be readily biodegradable.

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

 

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:
other: Guideline study, GLP.
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))
GLP compliance:
yes
Oxygen conditions:
aerobic
Inoculum or test system:
sewage, predominantly domestic, non-adapted
Details on inoculum:
30 mg/l; BOD measurement 
The inoculum was a mixture of activated sewage whose seed was collected  from ten different sites in Japan (4 city sewage plant, 3 river water samples, 1 lake water sample and 2 bay water  samples).
Duration of test (contact time):
28 d
Initial conc.:
100 mg/L
Based on:
test mat.
Details on study design:
-Water Temperature: 25±1ºC
-Volume of test solution 300 mL
Reference substance:
aniline
Parameter:
other: BOD
Value:
88
Sampling time:
28 d
Parameter:
% degradation (test mat. analysis)
Value:
100
Sampling time:
28 d
Details on results:
percentage biodegradation(%)
3 replicates average
(1) BOD 90 86 89 88
(2) GC 100 100 100 100

biodegradation in mg BOD
71.9 68.9 71.5

ThOD = 266.3 mg O/mg

Average overall biodegradation:
88 % - ultimate biodegradation as determined by biochemical oxygen demand
100 % - primary degradation as determined by specific analysis (GC)

The 10 day criterion for ready biodegradability was met.

Please note: y-scale of graph is mg biochemical oxygen demand (not %degradation)

Interpretation of results:
readily biodegradable
Conclusions:
In a valid guideline study average overall biodegradation was 88 % (ultimate biodegradation as determined by biochemical oxygen demand) and
100 % (primary degradation as determined by specific analysis (GC)).
Executive summary:

In a valid guideline study average overall biodegradation was 88 % (ultimate biodegradation as determined by biochemical oxygen demand) and 100 % (primary degradation as determined by specific analysis (GC)).

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:
other: Method in accordance with OECD Guideline, GLP.
Qualifier:
according to guideline
Guideline:
OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)
GLP compliance:
yes
Oxygen conditions:
aerobic
Inoculum or test system:
other: activated sewage sludge bacteria
Details on inoculum:
Aeration stage of the HRC Limited sewage treatment plant treating predominantly domestic sewage
Duration of test (contact time):
28 d
Initial conc.:
3 mg/L
Based on:
test mat.
Parameter followed for biodegradation estimation:
other: Percent biodegradation determined by comparing oxygen depletion value with the corresponding ThOD
Details on study design:
Sampling at 0, 5, 15 and 28 days
20°C
Reference substance:
benzoic acid, sodium salt
Parameter:
% degradation (O2 consumption)
Value:
86
Sampling time:
28 d
Remarks on result:
other: Oxygen depletion = 4.325 mg O2/L; ThOD = 5.01 mg O2/L
Details on results:
Oxygen depletion in the inoculated and non-inoculated control series were within prescribed limits.
The substance passed the "time window" criterion (60% degradation within 10 days of attaining the 10% level)
Results with reference substance:
87% degradation within 28 days

Mean oxygen depletion and percentage biodegradation values

Culture medium

Day 5

Day 15

Day 28

(a) Dilution water without inoculum

    02depletion (mgO2/I)

 

0.175

 

0.275

 

0.250

(b) Dilution water with inoculum

    02depletion (mgO2/I)

 

0.100

 

0.300

 

0.375

(c) Test substance (3 mg/l)

    02depletion (mgO2/I)

    % degradation

 

3.050

61

 

3.000

60

 

4.325

86

(d) . Standard substance (3 mg/l)

    02depletion (mgO2/I)

    % degradation

 

3.275

65

 

3.450

69

 

4.375

87

t1/2: 10.3 days

Validity criteria fulfilled:
yes
Interpretation of results:
readily biodegradable
Conclusions:
In a valid guideline study, the substance was considered readily biodegradable (86% degradation within 28 days).
Executive summary:

In a valid guideline study, the substance was considered readily biodegradable (86% degradation within 28 days).

Endpoint:
biodegradation in water: ready biodegradability
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
Further information is included as attachment. Please also see attached justification.

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The constituents of the UVCB substance NUMA (Nonyl-Undecyl methacrylate) are structurally related mono alkyl methacrylate esters differing only in the respective alcoholic moieties. The main proportion of these esters are of the n-type the minor proportion of the iso type. Considering the small amount of iso-types and the negligible differences in (eco-) toxicological properties between the n- and iso types, in this assessment both types of one ester with one specific chain length are assessed together as a whole.
Further information is included as attachment. Please also see attached justification Chapter 1

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
Further information is included as attachment. Please also see attached justification Chapter 1.

3. ANALOGUE APPROACH JUSTIFICATION
Please see attached justification Chapter 1 and 3.

4. DATA MATRIX
Please see attached justification Chapter 1.
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Reason / purpose for cross-reference:
read-across source
Parameter:
other: read across
Remarks:
read across to several source substances
Remarks on result:
other: Based on read across to analogues substances and/or constituents of the target UVCB substance. The substance is regarded readily biodegradable.
Validity criteria fulfilled:
not applicable
Interpretation of results:
readily biodegradable
Conclusions:
The target NUMA covering all methacrylates being constituents of this UVCB substance are readily biodegradable.
Executive summary:

Reflecting the existing test results, ready biodegradability is expected for all constituents and therefore also for the UVCB target substance NUMA. In this context, deliberating the different concentrations of the constituents is not necessary, as the outcome is the same for all constituents.

The read across and the assessment were conducted with a high level of confidence.

Description of key information

Reflecting the existing test results, ready biodegradability is expected for all constituents and therefore also for the UVCB target substance NUMA. In this context, deliberating the different concentrations of the constituents is not necessary, as the outcome is the same for all constituents.

The read across and the assessment were conducted with a high level of confidence.

Key value for chemical safety assessment

Biodegradation in water:
readily biodegradable

Additional information