Bis(2-(2-butoxyethoxy)ethyl) adipate

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:

22 Sept - 20 Oct 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Analytical purity not stated.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Activated sludge was collected from the aeration stage of the Severn Trent Plc sewage treatment plant at Belper, Derbyshire, which treats predominantly domestic sewage. (date of collection: 22 Sept 1992)
- Pretreatment: The activated sludge was homogenized for 10 min. The solids were then removed by centrifuging and the supernatant was taken for testing.

Duration of test (contact time):

28 d

Initial conc.:

10 mg/L

Based on:

test mat.

Initial conc.:

20 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: Solution 1: FeCl3x6H2O = 0.25 g/L; Solution 2: MgSO4x7H2O = 22.5 g/L; Solution 3: CaCl2 = 27.5 g/L; Solution 4: (NH4)2SO4 = 40 g/L; Solution 5: KH2PO4 = 8.5 g/L, K2HPO4 = 27.75 g/L, Na2HPO4x7H2O = 33.4 g/L, NH4Cl = 1.7 g/L
4 mL Solution 1, 1 mL of each Solution 2, 3 and 4 and 2 mL Solution 5 were added to 1 L of purified water
- Test temperature: 21 ± 1 °C
- pH: day 27: 10 mg/L = 5.4; 20 mg/L = 5.6; control = 5.3; standard = 5.4
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: 5 L glass culture vessel containing 3 L
- Number of culture flasks/concentration: 2 (1 per test substance concentration)
- Method used to create aerobic conditions: The culture vessels were sealed and CO2-free air bubbled through the solution at a rate of ~ 2 bubbles per second and stirred continuously by magnetic stirrers.
- Measuring equipment: Ionics 555 TOC analyser
- Details of trap for CO2 and volatile organics if used: CO2 was absorbed using 2 500 mL Dreschel bottles filled with 350 mL 0.05 M NaOH

SAMPLING
- Sampling frequency: Samples (2 mL, in triplicate) were taken from the first absorber vessel on days 0, 1, 2, 3, 6, 8, 10, 14, 16, 21, 23, 27 and 28. The second absorber vessel was sampled on days 0 and 28.
- Sampling method: On day 27 the pH of each test vessel was measured and 1 mL of concentrated HCl added to drive of inorganic carbonate. The vessels were aerated overnight and the final samples were taken from both absorber vessels on day 28.

CONTROL AND BLANK SYSTEM
- Inoculum blank: 2 (with and without standard)

Reference substance:

benzoic acid, sodium salt

Remarks:

20 mg/L

Parameter:

% degradation (CO2 evolution)

Value:

74

Sampling time:

28 d

Remarks on result:

other: 10 mg/L test substance concentration

Parameter:

% degradation (CO2 evolution)

Value:

82

Sampling time:

28 d

Remarks on result:

other: 20 mg/L test substance concentration

Details on results:

The test substance reached biodegradation values of 74 (10 mg/L) and 82% (20 mg/L) after 28 days test duration. Furthermore,
degradation over 60% took place within the 10d-window period. Therefore, the test substance can be considered as readily biodegradable.

Results with reference substance:

Sodium acetate reached a biodegradation value of 86% at the end of the test. Besides, degradation over 60% occurred within 14 days (79%).

Validity criteria fulfilled:

not specified

Remarks:

See "Any other information on results incl. tables"

Interpretation of results:

readily biodegradable

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

01 Sep 1983 - 20 Jan 1984

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Qualifier:

according to guideline

Guideline:

other: Circular on Test Methods of New Chemical Substances (Japan), Biodegradation test

Deviations:

no

GLP compliance:

not specified

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

14 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

TOC removal

Parameter followed for biodegradation estimation:

test mat. analysis

Remarks:

by LC

Details on study design:

TEST CONDITIONS
- Composition of medium: recomended medium in the guideline
- Test temperature: 25 °C
- Suspended solids concentration: 30 mg/L

TEST SYSTEM
- Culturing apparatus: closed oxygen consumption measuring machine with 300 mL culture bottle
- Number of culture flasks/concentration: 1 (water + test substance), 3 (sludge + test sub.), 1 (sludge + reference sub.), 1 (sludge)

SAMPLING
- Sampling frequency: continuously
- Sterility check if applicable: no
- Sample storage before analysis: no data

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes

Reference substance:

aniline

Parameter:

% degradation (O2 consumption)

Value:

86

Sampling time:

14 d

Parameter:

% degradation (TOC removal)

Value:

98

Sampling time:

14 d

Parameter:

% degradation (test mat. analysis)

Value:

100

Sampling time:

14 d

Details on results:

see table 1

Results with reference substance:

BOD of aniline was 62% at day 7.

Table 1. Results of BOD

	day 7	day 14
	BOD [mg]	BOD [mg]
Sludge + Test sub.	27.8	58.0
Sludge + Test sub.	28.3	59.5
Sludge + Test sub.	32.0	60.3
Water + Test sub.	0	0
Control blank	4.5	5.3
Sludge + Aniline	61.0	73.0

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Description of key information

Readily biodegradable: 74 - 82% in 28 days (CO2 evolution, OECD 301B)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

Two studies investigating the ready biodegradability of Bis(2-(2-butoxyethoxy)ethyl) adipate (CAS No. 141-17-3) are available. The key study was conducted according to OECD 301B under GLP conditions using non-adapted activated sludge as inoculum. Mean degradation of 74 (10 mg test material/L) and 82% (20 mg test material/L) were observed after 28 days. The 10-day-window was met. Hence, the test substance is determined to be readily biodegradable according to OECD criteria. This conclusion is supported by an additional study on aerobic degradation conducted by Japanese authorities according to the “Circular on test methods of new chemical substances, biodegradation test”. In this study the test substance reached a biodegradation of 86% within 14 days. 

Hence, Bis(2-(2-butoxyethoxy)ethyl) adipate can be considered readily biodegradable according to OECD criteria.