Butane-1,3-diol

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 Sep - 15 Oct 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Day 5, two vessels: air flow fell to a minimum of 20 mL/min, which is slightly below the recommended 30 - 100 mL/min

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Deviations:

yes

Remarks:

Day 5, two vessels: air flow fell to a minimum of 20 mL/min, which is slightly below the recommended 30 - 100 mL/min

GLP compliance:

yes

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): Oakley sewage treatment works
- Laboratory culture: no
- Preparation of inoculum for exposure: homogenisation, filtration through Whatman GFC filter paper
- Concentration of sludge: 30 mg suspended solids/L

Duration of test (contact time):

29 d

Initial conc.:

10 mg/L

Based on:

DOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral salts medium
- Test temperature: 21.3 - 23.6 °C
- pH: 7.5-7.7
- pH adjusted: no
- Aeration of dilution water: yes
- Suspended solids concentration: 30 mg/L
- Continuous darkness: yes


TEST SYSTEM
- Culturing apparatus: 5 L glass culture bottles
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: bubbling with CO2-free air (30-100 mL/min)
- Test performed in closed vessels due to significant volatility of test substance: no
- Test performed in open system: yes
- Details of trap for CO2 and volatile organics if used: air outlet was connected to three Dreschel bottles in series, each containing 100 mL of 0.025 N of barium hydroxide


SAMPLING
- Sampling frequency: every second day
- Sampling method: 1st Dreschel bottle was disconnected and used for analysis; a fresh bottle was connected to the outlet at the end of the series


CONTROL AND BLANK SYSTEM
- Inoculum blank: bottles No. 1, 2
- Abiotic sterile control: no
- Toxicity control: bottle No. 6
- Other:
reference: bottle No. 3
test substance: bottles No. 4, 5


STATISTICAL METHODS: CO2/ThCO2

Reference substance:

benzoic acid, sodium salt

Key result

Parameter:

% degradation (CO2 evolution)

Value:

81

Sampling time:

29 d

Results with reference substance:

The reference substance sodium benzoate showed the expected biodegradation results (for details please see table below).

Sampling day	Degradation (% CO2/ThCO2)
	Reference substance	Toxicity control	Test substance
			Culture 1	Culture 2	Mean
2	19	23	1	1	1
4	54	54	28	27	28
6	65	63	40	39	40
8	72	-	49	48	49
10	76	-	57	55	56
12	79	-	62	59	61
14	80	-	67	64	66
19	82	-	77	73	75
24	82	-	82	78	80
28	83	-	82	79	81
29	83	-	82	79	81

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Butane-1,3-diol is readily biodegradable as demonstrated in the Modified Sturm Test performed according to OECD 301B.

Executive summary:

The ready biodegradability of 1,3 -butanediol was studied in a Modfied Sturm Test following OECD 301B. The test substance was degraded to 81% (CO₂/ThCO₂) after 29 days. The 10 -days window was met. The validity criteria were fulfilled. 1,3 -Butanediol is readily biodegradable according to OECD criteria.

Description of key information

Readily biodegradable as demonstrated in OECD TG 301 B (Barnes, 2000). 

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

The ready biodegradability of 1,3 -butanediol was studied in a Modfied Sturm Test following OECD 301B. The test substance was degraded to 81% (CO₂/ThCO₂) after 29 days. The 10 -days window was met. The validity criteria were fulfilled. 1,3 -Butanediol is readily biodegradable according to OECD criteria (Barnes, 2000).