N'-[3-(dimethylamino)propyl]-N,N-dimethylpropane-1,3-diamine

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study, conducted to GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 A (Ready Biodegradability: DOC Die Away Test)

GLP compliance:

yes

Specific details on test material used for the study:

Name of test substance: 3-Diethylaminopropylamine
Test substance No.: 05/0264-1
Charge: 21418856P0
CAS No.: 104-78-9
- Purity: >99.5
- Homogeneity: homogeneous
- Stability: The stability of the test substance under storage conditions over the test period is guaranteed by the sponsor and the sponsor holds this responsibility.

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Municipal activated sludge taken from a laboratory wastewater treatment plant fed with municipal sewage and synthetic wastewater.
- Laboratory culture: yes
- Concentration of sludge: 30 mg/L (dry substance)

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

DOC

Initial conc.:

32 mg/L

Based on:

test mat.

Details on study design:

TEST CONDITIONS
- Composition of medium:
915-920 ml dest. water
13 ml inorganic medium
66 ml test substance solution
= Total test volume: 1000 ml

- Aeration of dilution water: yes

TEST SYSTEM
- Method used to create aerobic conditions: aeration

SAMPLING
- Sampling frequency: day 0, 1, 3, 5, 7, 10, 14, 17, 21, 24, 27, 28

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

Reference substance:

aniline

Parameter:

% degradation (DOC removal)

Value:

>= 90 - <= 100

Sampling time:

28 d

Details on results:

Kinetic of test substance (in %):
= 3 after 10 day(s)
= 20 after 14 day(s)
= 86 after 17 day(s)
Kinetic of control substance (in %):
= 78 after 3 day(s)

Results with reference substance:

90-100 % biodegradation after 14 d

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

Data from the related substance 3-aminopropyldiethylamine is used for the read across. The justification for read across is attached to IUCLID Section 13.

Reason / purpose for cross-reference:

read-across source

Key result

Parameter:

% degradation (DOC removal)

Value:

>= 90 - <= 100

Sampling time:

28 d

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-08-10 - 2011-09-14

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Specific details on test material used for the study:

- Name of test material (as cited in study report): Bis-DMAPA
- Physical state: liquid
- Analytical purity: 97.8%
- Purity test date: 30 May 2011
- Total amine: 16.02 meq/g
- Lot/batch No.: PFW110019
- Supplier: SGS Belgium N.V.
- Stability under test conditions: not reported
- Storage condition of test material: lab

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): Totnes Sewage Treatment Works, Totnes, Devon, UK, collected on 9 August 2011
- Storage conditions: aerated at room temperature and pH maintained at 7.0 ± 1.0
- Preparation of inoculum for exposure: 7 days prior to start of exposure the activated sludge was centrifuged, washed and resuspended in the mineral medium and the solids concentration determined
- Initial concentration of sludge in test vessels: 30 mg/L

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 CONDITIONS
- Composition of medium: OECD standard medium
- Test temperature: 22 ± 1 °C
- pH: 7.1-7.2 in the inoculum blank, 4.9-5.1 in the bis-DMAPA bottles
- pH adjusted: yes, to 7.4 prior to testing
- Suspended solids concentration (initial): 30 mg/L
- Continuous darkness: yes, test performed in dark glass bottles

TEST SYSTEM
- Culturing apparatus: Oxitop™ respirometer (Wissenschaftlich-Technische Werkstätten, GmbH, Germany) - each unit consisting of a dark glass 500 mL bottle with Oxitop™ bottle top containing a piezoresistive electronic pressure sensor
- Bottles were situated on a magnetic stirrer in a constant temperature incubator
- Number of culture flasks/concentration: 3 inoculum blanks (inoculum only), 3 positive controls (reference substance (100 mg/L sodium benzoate) + inoculum), 3 test substance bottles (test substance (100 mg/L Bis-DMAPA) + inoculum)
- CO2 produced by respiration was absorbed by a potassium hydroxide (KOH) solution placed in a seal cup in the neck of each bottle
- The Oxitop™ controller collected pressure values from the measuring tops and calculated the BOD (mg/L)
- Oxygen uptake values were corrected for the inoculum blank and biodegradation calculated as % of ThOD

STOCK SOLUTIONS
- A primary stock solution containing 1000 mg/L Bis-DMAPA or 1000 mg/L sodium benzoate was prepared in RO water
- Stock solutions were clear and colourless
- Stock solutions were prepared on day of exposure start

SAMPLING
- Sampling frequency:
Oxygen uptake was recorded automatically every 112 minutes during 28 days.
At day 0 pH was measured in a single bottle of the inoculum blanks and positive controls and was measured and adjusted in all bottles containing the test substance.
At the end of testing pH was measured in all test bottles (day 28).

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: no
- Toxicity control: yes, with sodium benzoate 100 mg/L

DATA ANALYSIS
- Oxygen uptake values were corrected for the inoculum blank and biodegradation calculated as % of ThOD of the substance under consideration.

Reference substance:

benzoic acid, sodium salt

Preliminary study:

Not applicable.

Test performance:

Maximum mean level of biodegradation (based on BOD:ThOD ratio) of sodium benzoate was 63%, > 60% of which was achieved within the 10-day window, thus confirming that the activated sludge was viable.

Key result

Parameter:

other: ThOD

Value:

60

Sampling time:

28 d

Remarks on result:

other: 60% degradation was not reached within 10-d window

Details on results:

Lag phase days 0 to 6
Degradation phase days 6 to 16
10-day window days 6 to 16
Mean oxygen uptake of inoculum blank was < 60 mg/L, as required in the OECD guideline.
Variation between replicate biodegradation values was < 20% after the 10-day window (at plateau), and on day 28, as required in the OECD guideline.
ThOD of Bis-DMAPA was calculated as 3.42 g O2/g, assuming nitrification.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable, but failing 10-day window

Conclusions:

This study determined the ready biodegradability of the test substance in a 28-day manometric respirometry test according to OECD guideline 301F in the presence of activated sludge (30 mg SS/L) from a waste water treatment plant treating mainly domestic sewage. The maximum mean level of biodegradation was 60% (expressed as % of the ThOD), showing good potential for biodegradation, however, failing the 10-day window. The results of this test can be considered reliable.

Description of key information

Two key studies are available for endpoint coverage. The study of Commander and Stevens (2011) was carried out with the test substance according to the OECD guideline 301F, while the study of BASF (2005) was carried out according to the OECD guideline 301A with a structural analogue substance and used in a read across. Based on the results from both studies, the substance is concluded to be readily biodegradable according to the OECD criteria.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

The study of Commander and Stevens (2011) was performed under GLP and assigned a Klimisch score of 1. This study determined the ready biodegradability of the test substance in a 28-day manometric respirometry test according to OECD guideline 301F in the presence of activated sludge (30 mg SS/L) from a waste water treatment plant treating predominantly domestic sewage. The maximum mean level of biodegradation was 60% (expressed as % of the ThOD), showing good potential for biodegradation, however, failing the 10-day window.

Additionally, the ready biodegradability of the substance is further supported by read across to the structural analogue substance 3-aminopropyldiethylamine (CAS 104-78-9). The study of BASF (2005) was carried out according to the OECD guideline 301 under GLP and was assigned a Klimisch score of 1. In this study, a lag phase of 10-14 days was observed. Nevertheless, the substance was considered to be readily biodegradable as the degradation reached 90 to 100% after 20 days and the 10-day window was kept.

Based on the results from both studies, the substance is concluded to be readily biodegradable.