Dodecylbenzenesulphonic acid, compound with 2-amino-2-methylpropan-1-ol (1:1)

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

Remarks:

the tested substance is AMP one of the components of the compound

Adequacy of study:

key study

Study period:

Not applicable

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to test guidelines and in accordance with GLP.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3110 (Ready Biodegradability)

Qualifier:

according to guideline

Guideline:

EU Method C.4-D (Determination of the "Ready" Biodegradability - Manometric Respirometry Test)

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):Not applicable

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge (e.g. location, sampling depth, contamination history, procedure):The microbial inoculum consisted of activated sludge mixed liquor, collected from the oxidation ditch bioreactor at the Midland Municipal Wastewater Treatment Plant (Midland, Michigan) on November 17, 2009. This facility treats an excess of 11 million liters of wastewater per day, of which > 90% is from domestic sources. The activatedsludge was collected one day prior to initiation of the test, and was continuously aerated until used.- Laboratory culture: not applicable- Method of cultivation:not specified in the report- Storage conditions:continuously aerated until used- Storage length: one day prior to the initiation of the test- Preparation of inoculum for exposure: Prior to use, the activated sludge was screened through 500 μm nylon mesh, and briefly homogenized in a Waring blender (Waring Products Inc., Torrington, Connecticut). The mixed liquor suspended solids (MLSS) content of the homogenized sludge was determined gravimetrically to be 1,987 mg/L. Based on this determination, 245 mL of the homogenized activated sludge was added to 16 liters of the sterilized mineral medium to yield a final MLSS concentration of 30 mg/L.- Pretreatment:not specified in the report- Concentration of sludge:30 mg/L- Initial cell/biomass concentration:not applicable- Water filtered: yes- Type and size of filter used, if any:

Duration of test (contact time):

28 d

Initial conc.:

11.1 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

CO2 evolution

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS- Composition of medium:A defined mineral medium was prepared as specified in OECD Guideline 301F, by dissolving appropriate volumes of concentrated mineral stock solutions in Milli-Q water.- Additional substrate:not applicable- Solubilising agent (type and concentration if used):not applicable- Test temperature:20 and 24°C.- pH:7.2 to 7.6- pH adjusted: not specified in the report- CEC (meq/100 g):- Aeration of dilution water:- Suspended solids concentration:The initial blank-corrected DOC concentration in these Test Suspensions (mean ± 1 SD) was 5.86 ± 0.1 mg/L, thus indicating complete dissolution of test substance in the biodegradation reaction mixtures.- Continuous darkness:yesTEST SYSTEM- Culturing apparatus:designed 1-liter glass reaction vessels, each containing a 500-mL portion of the inoculated mineral medium. The reaction vessels are designed with flat glass bottoms to accommodate stirring with large PTFE-coated magnetic stir bars. These vessels are also fitted with 20 x 105 mm glass side baffles to facilitate complete mixing/aeration of the stirred reaction mixtures.- Number of culture flasks/concentration:one- Method used to create aerobic conditions:mixing/aeration of the stirred reaction mixtures- Method used to create anaerobic conditions:not applicable- Measuring equipment:Columbus Micro-Oxymax automated respirometry system- Test performed in closed vessels due to significant volatility of test substance:yes- Test performed in open system:no- Details of trap for CO2 and volatile organics if used:SAMPLING- Sampling frequency: oxygen and CO2 in the headspace of each reaction vessel were recorded at six-hour intervals over the entire 28-day test period- Sampling method:Columbus Micro-Oxymax automated respirometry system- Sterility check if applicable:not specified in the report- Sample storage before analysis:not specified in the reportCONTROL AND BLANK SYSTEM- Inoculum blank: yes- Abiotic sterile control:yes- Toxicity control: yesSTATISTICAL METHODS:

Reference substance:

aniline

Preliminary study:

NOt applicable

Test performance:

Several criteria are specified by the OECD for validating the results of its tests for ready biodegradability. These criteria are based on parameters such as inoculum viability, precision among replicate reaction mixtures, maintenance of temperature, and pH of the reaction mixtures.The results indicate that the procedures used to prepare, incubate, and analyze the biodegradation reaction mixtures resulted in sufficient precision in the test results.

Parameter:

% degradation (O2 consumption)

Value:

89.3

St. dev.:

10.8

Sampling time:

28 d

Parameter:

% degradation (CO2 evolution)

Value:

90.9

St. dev.:

2.9

Sampling time:

28 d

Parameter:

% degradation (DOC removal)

Value:

98.1

St. dev.:

1.7

Sampling time:

28 d

Details on results:

Refer below to the other information section

Results with reference substance:

The complete biodegradation of aniline indicated from measurements of BOD and CO2 evolution was confirmed by analyses of DOC removal. DOC was removed by 98.6% in both replicate Positive Control mixtures.

Biological Oxygen Demand (BOD): The time required for biodegradation to exceed 10% DO2 (i.e., the lag period) was 7.9 days and the 60% DO2 level was exceeded after 9.6 days. By the end of the 28- day test, biodegradation of the test substance reached 89.3 ± 10.8% DO2 (mean ± 1SD).

CO2 Evolution: Biodegradation of the substance exceeded 10% DCO2 after 6.9 days and after 28 days reached 90.9 ± 2.9% DCO2 (mean ± 1SD). Therefore, the rates and extents of biodegradation determined from CO2 evolution closely reflected those determined from the BOD values.

DOC Analyses DOC analyses also indicated that biodegradation of the test substance occurred under the conditions of this test. The initial DOC concentration (mean ± 1 SD) in the Test Suspensions was 5.86 ± 0.1 mg/L, which indicated that the test substance components were completely dissolved in the inoculated mineral medium. The DOC concentration after 28 days was 0.110 ± 0.1 mg/L, which equates to a 98.1% reduction of the initial DOC concentration.

The complete biodegradation of aniline indicated from measurements of BOD and CO2 evolution was confirmed by analyses of DOC removal. DOC was removed by 98.6% in both replicate Positive Control mixtures.

The recorded values from the temperature reference vessel averaged 21.9 ± 0.4°C (± 1SD, n=17), and the minimum and maximum recorded temperatures were 21.0 and 22.8°C, respectively, over the entire duration of this test.

The pH of the biodegradation reaction mixtures remained within the required range of 7.2 to 7.6 over the duration of this test. The pH of the Test Suspensions decreased by no more than 0.29 pH units from their initial values over 28 days, and showed only a 0.06 pH unit (maximum) difference relative to the Inoculum Blanks at the end of the test. This minimal variation in pH indicates that the mineral medium contained adequate buffering capacity for the inoculum and test substances evaluated in this test.

The Toxicity Control mixtures containing 100 mg/L aniline and 10.9 mg/L of the test substance showed no evidence for inhibition of the microbial inoculum by the test substance. The onset and rate of biodegradation in the Toxicity Control mixture closely matched that in the Positive Controls further indicating that the test substance did not cause toxicity to or inhibition of the microbial inoculum.

A single Abiotic Control mixture was included in the experimental design to determine the extent to which abiotic processes may result in degradation of the test substance. The mixture contained 11.0 mg/L of test substance in the inoculated mineral medium, which was chemically sterilized by addition of 250 mg/L HgCl2. The Abiotic Control mixture exhibited no O2 consumption or CO2 production over the duration of the 28-day test (data not shown). Therefore, the O2 consumption and CO2 production in the Test Suspensions was solely attributed to biodegradation of the test substance.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The AMP (2-AMINO-2-METHYL-1-PROPANOL) test substance exceeded 60% biodegradation within 9.6 days of the start of the test and within the 10-day window detailed in OECD 301F guideline. The results of this test demonstrated that AMP can be classified as “readily biodegradable”, according to the OECD 301F: Manometric Respirometry Test.

Executive summary:

The ready biodegradability of AMP (2-amino-2-methyl-1-propanol) was evaluated using the OECD Guideline No. 301F: Manometric Respirometry Test. The test employed biodegradation reaction mixtures (500 mL) containing a defined mineral medium, which was inoculated with 30 mg/L activated sludge (dry solids) collected from the City of Midland Wastewater Treatment Plant (Midland, Michigan). Biodegradation of AMP was evaluated at a concentration of 11.1 mg/L, which was equivalent to 21.8 mg/L theoretical oxygen demand (ThOD). The onset of AMP biodegradation (i.e. BOD ≥ 10% of theoretical oxygen demand, ThOD) occurred after 7.9 days in the Test Suspensions, and biodegradation exceeded the pass level of 60% ThOD consumption within 1.7 days thereafter. At the end of the 28-day test, the extent of biodegradation based on BOD, CO2 evolution, and dissolved organic carbon (DOC) removal reached 89.3 ± 10.8%, 90.9± 2.9%, and 98.1 ± 1.7% (mean ± 1 Std. Dev.), respectively. Thus, biodegradation exceeded both the pass level and 10-day window criteria for classification as “readily biodegradable”. The Toxicity Control mixture showed no apparent toxic or inhibitory effects of the AMP substance on the inoculum employed in this test; and no net consumption of oxygen or DOC removal was observed in the Abiotic Control mixture. All test parameters met the OECD-specified validation criteria for ready biodegradability tests. Biodegradation of the reference compound aniline exceeded the pass level within 6.6 days, and thus confirmed the viability of the inoculum. Other experimental parameters, such as reaction mixture pH, incubation temperature, and total oxygen consumption in the Inoculum Blanks, fell within the ranges required by the OECD guideline. Therefore, the results of this test indicate that AMP does meet OECD criteria for “ready biodegradability” in the Manometric Respirometry test.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Remarks:

the tested substance is DDBSA one of the components of the compound

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Remarks:

the information in the publication is limited to what is included in the summary, test substance identification not completely clear

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test)

GLP compliance:

not specified

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

The activated sludge sample was obtained from the pilot-plant during period A in this study.

Duration of test (contact time):

28 d

Initial conc.:

25.1 mg/L

Based on:

test mat.

Details on study design:

This test was carried out according to the guidelines of OECD test method encoded 301F. An automated sapromate(Voith) was used to follow O2 consumption in response to LAS mineralisation. A test with a blank inoculm was included as well as a test with 109mg/l of the easily biodegradable potassium hydrogen phthalate (PHP) to serve as a method control. All the tests were carried out in duplicate over a period of 28 days at a temperature of 20 deg C.

Reference substance:

other: potassium hydrogen phthalate (PHP)

Key result

Parameter:

% degradation (O2 consumption)

Value:

> 60

Remarks on result:

other: within 28days

Details on results:

The O2-consumption data generated in the ready biodegradability tests(data not shown) showed that LAS is readily biodegradable as defined by the OECD Guidelines: more than 60% of mineralisation was achieved within 28 days and this level was reached within a time windows of 10 days from the start of mineralisation. From the O2-consumption data a biomass-yield Y of 0.50 (+/-) 0.02 mgO2/mgO2 and a maximum specific growth rate of 0.050 (+/-) 0.003/h were estimated.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Data of following studies are demonstrating rapid biodegradation of C12- LAS (including Na-LAS) under aerobic and anaerobic conditions. The result is that more than 60% of mineralisation was achieved within 28 days.

Executive summary:

C12-LAS is readily biodegradable (more than 60% by mineralization wihin 28days) [OECD TG 301 F].

Description of key information

Both dissociation products of the substance DDBSA and AMP are readily biodegradable, therefore it can be expected that the substance is also readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater