3-butoxypropylamine

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: ready biodegradability

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

other:

Reference 2

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05 March 2018 - 17 April 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 B (Inherent biodegradability: Zahn-Wellens/EMPA Test)

Qualifier:

according to guideline

Guideline:

EU Method C.9 (Biodegradation: Zahn-Wellens Test)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 835.3200 (Zahn-Wellens / EMPA Test)

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

- Identification: BOPA
- CAS Number: 16499-88-0
- Chemical Name: 3-Butoxypropylamine
- Physical state/Appearance: clear colorless liquid
- Batch: PFW160573
- Purity: 99.39%
- Molecular Weight: 131.22 g/mol
- Receipt Date: 04 May 2017
- Expiry Date: 26 September 2018
- Storage Conditions: room temperature, in the dark

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

Severn Trent Water Plc sewage treatment plant at Loughborough, Leicestershire, UK (Aeration stage)
- Laboratory culture: maintained on continuous aeration upon receipt
- Method of cultivation: Activated sewage sludge was washed twice by settlement and resuspension in mineral medium to remove any excessive amounts of Dissolved Organic Carbon (DOC). A sub-sample of the washed sewage sludge was then removed and the suspended solids concentration determined.
- Initial cell/biomass concentration: 300 mg suspended solids/liter in order to give an inoculum to carbon ratio of 3:1.
- Water filtered: yes
- Type and size of filter used, if any: Gelman 0.45 µm AcroCap filter

Duration of test (contact time):

ca. 28 d

Initial conc.:

ca. 100 other: mg carbon/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

DOC removal

Details on study design:

TEST CONDITIONS
- Composition of medium:
Nutrient Stock Solutions
Solution a KH2PO4: 8.50 g/L
K2HPO4: 21.75 g/L
Na2HPO4.2H2O: 33.40 g/L
NH4Cl: 0.50 g/L
pH = 7.4
Solution b CaCl2: 27.50 g/L
Solution c MgSO4.7H2O: 22.50 g/L
Solution d FeCl3.6H2O: 0.25 g/L
(In order to avoid having to prepare solution (d) immediately before use, one drop of concentrated HCl per liter was added as a preservative).
Preparation of mineral medium for washing the activated sewage sludge
To 10 liters (final volume) of purified water* was added the following:
100 mL of Solution a
10 mL of Solution b
10 mL of Solution c
10 mL of Solution d
Preparation of mineral medium for biodegradation test
To approximately 500 mL of purified water* was added the following:
20 mL of Solution a
2 mL of Solution b
2 mL of Solution c
2 mL of Solution d
Activated sludge to give 300 mg suspended solids per liter final volume.
The volume was then adjusted to 2 liters using purified water after the addition of test item and/or reference item if applicable.
(*Ion exchange and reverse osmosis treated tap water (Elga Optima 15+ or Elga Purelab Option – R15 BP))

- Test temperature: 20 - 25°C
- pH: 7 - 8
- pH adjusted: yes
- Aeration of dilution water: Constantly aerated with compressed air via glass tubes and stirred constantly by a magnetic stirrer.
- Suspended solids concentration: 300 mg suspended solids/liter
- Continuous darkness: yes

TEST SYSTEM
- Number of culture flasks/concentration:
* inoculum control, duplicate
* reference item (diethylene glycol), duplicate
* test item, duplicate
* test item plus diethylene glycol, one replicate

- Method used to create aerobic conditions: continuous aeration
- Method used to create anaerobic conditions: n/a
- Measuring equipment: Shimadzu TOC-VCPH TOC analyzer
- Test performed in closed vessels due to significant volatility of test substance: no

SAMPLING
- Sampling frequency: Samples taken for analysis at 0 and 3 hours and on Days 1, 7, 14, 21, 27 and 28.
- Sampling method: Samples (approximately 30 mL) were filtered through 0.45 µm Gelman AcroCap disposable filters. The first approximate 5 mL of filtrate was discarded.

CONTROL AND BLANK SYSTEM
- Inoculum blank: consisting of inoculated mineral medium
- Abiotic sterile control: n/a
- Toxicity control: containing the test item and diethylene glycol
- Other: not specified

Reference substance:

diethylene glycol

Preliminary study:

The preliminary investigation indicated that the test item did not adsorb to filter matrices or activated sewage sludge. Therefore, for the purpose of the test, the samples taken for DOC analysis were filtered to remove the suspended solids present without causing a loss of any test item.

Test performance:

Diethylene glycol attained 99% biodegradation after 14 days and 100% biodegradation after 28 days, thereby confirming the suitability of the inoculum and culture conditions.
The toxicity control attained 98% biodegradation after 14 days and 99% biodegradation after 28 days, therefore confirming that the test item was not toxic to the sewage treatment micro-organisms used in the study.

Key result

Parameter:

% degradation (DOC removal)

Value:

ca. 11

St. dev.:

0

Sampling time:

1 d

Key result

Parameter:

% degradation (DOC removal)

Value:

ca. 15

St. dev.:

0

Sampling time:

7 d

Key result

Parameter:

% degradation (DOC removal)

Value:

ca. 98

St. dev.:

0

Sampling time:

14 d

Key result

Parameter:

% degradation (DOC removal)

Value:

ca. 99

St. dev.:

0

Sampling time:

21 d

Key result

Parameter:

% degradation (DOC removal)

Value:

ca. 99

St. dev.:

0

Sampling time:

27 d

Key result

Parameter:

% degradation (DOC removal)

Value:

ca. 99

St. dev.:

0

Sampling time:

28 d

Details on results:

The procedure control, diethylene glycol attained 99% biodegradation after 14 days and 100% biodegradation after 28 days, thereby confirming the suitability of the inoculum and culture conditions.
The toxicity control attained 98% biodegradation after 14 days and 99% biodegradation after 28 days, therefore confirming that the test item was not toxic to the sewage treatment micro-organisms used in the study.
The pH values did not fall below 6.61 in any test vessel during the study and were readjusted to pH 7 to 8 where necessary on sampling days. Aerobic conditions in the test vessels were maintained throughout the study as dissolved oxygen concentrations remained at or above 7.01 mg O2/L in all culture vessels.
Table 1 shows the results of the percentage biodegradation.

Table 1. Percentage biodegradation

Day	% Biodegradation
	Procedure Control	Test Item	Toxicity Control
1	9	11	12
7	99	15	78
14	99	98	98
21	99	99	99
27	99	99	99
28	100	99	99

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable

Conclusions:

From DOC analysis the test item attained 98% biodegradation after 14 days and 99% biodegradation after 28 days exposure time. Between days 14 and 28 the biodegradation rate reached a plateau.
OECD Guideline No. 302B does not give any definitive pass levels for test items, however the “Revised Introduction to the OECD Guidelines for Testing of Chemicals, Section 3 (2006)” suggests that a figure of more than 20% biodegradation may be regarded as evidence for inherent, primary biodegradability. A figure of more than 70% mineralization may be regarded as evidence for ultimate inherent biodegradation.
The test item can therefore be considered to have exhibited evidence of ultimate biodegradation under the experimental conditions employed in this study.

Description of key information

One study (Covance, 2019) is included in this dossier and regarded as a key study (Klimisch score of 1). The biodegradability of 3-butoxypropan-1-amine was determined according to OECD 302B, EU Method C.9 and EPA OPPTS 835.3110. From DOC analysis the test item attained 98% biodegradation after 14 days and 99% biodegradation after 28 days exposure time. Between days 14 and 28 the biodegradation rate reached a plateau. OECD Guideline No. 302B does not give any definitive pass levels for test items, however the “Revised Introduction to the OECD Guidelines for Testing of Chemicals, Section 3 (2006)” suggests that a figure of more than 20% biodegradation may be regarded as evidence for inherent, primary biodegradability. A figure of more than 70% mineralization may be regarded as evidence for ultimate inherent biodegradation. The test item can therefore be considered to have exhibited evidence of ultimate biodegradation under the experimental conditions employed in this study.

Key value for chemical safety assessment

Biodegradation in water:

inherently biodegradable