2-Oxepanone, polymer with 1,4-butanediol

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:

Not reported

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:

no

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Secondary (biological) activated sludge was obtained from the RWZI Horstermeer in Nederhorst den Berg, The Netherlands on January 13, 1993. The RWZI Horstermeer was an activated sludge plant treating predominantly domestic waste water. The dry weight of this inoculum appeared to be 4.0 mg/ml.

Duration of test (contact time):

28 d

Initial conc.:

20 mg/L

Based on:

test mat.

Initial conc.:

10 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Reference substance:

acetic acid, sodium salt

Key result

Parameter:

% degradation (TOC removal)

Value:

ca. 60

Sampling time:

7 d

Remarks on result:

other: initial conc. 10 mg/l

Parameter:

% degradation (TOC removal)

Value:

ca. 84

Sampling time:

28 d

Remarks on result:

other: initial conc. 10 mg/l

Parameter:

% degradation (TOC removal)

Value:

ca. 42

Sampling time:

7 d

Remarks on result:

other: initial conc. 20 mg/l

Parameter:

% degradation (TOC removal)

Value:

ca. 56

Sampling time:

28 d

Remarks on result:

other: initial conc. 20 mg/l

Table 1: Results of the biodegradation test with CAPA 203 and sodium acetate. The results are expressed as CO₂ mg (cumulative) formed after 7, 14, 21, 28 and 29 days (n=2)

Concentration CAPA 203 (mg/l)	Concentration Sodium acetate (mg/l)	mg CO2 produced
		7 days	14 days	21 days	28 days	29 days
0	100	44.0	56.9	60.8	59.4	59.8
20	100	37.6	61.5	71.4	73.1	72.9
10	0	28.6	35.7	38.6	40.0	40.2
20	0	39.9	50.8	52.4	53.2	53.2

Table 2: Percentage degradation of 100 mg/l sodium acetate, 20 mg/l CAPA 203 in the presence of 100 mg/l sodium acetate and CAPA 203 at a concentration of 10 and 20 mg/l

	% biodegradation
	7 days	14 days	21 days	28 days	29 days
sodium acetate (100 mg/l)	44	57	61	60	60
CAPA 203 (20 mg/l) in the presence of sodium acetate (100 mg/l)	-7	5	11	14	14
CAPA 203 (10 mg/l)	60	75	81	84	84
CAPA 203 (20 mg/l)	42	53	55	56	56

Table 3: Results of the biodegradability test

Concentration CAPA 203 (mg/l)	Concentration Sodium acetate (mg/l)	mg CO2 of absorbed in the period
		0-7 days	7-14 days	14-21 days	21-28 days	28-29 days
0		15.3	8.6	4.9	1.3	1.1
0		15.8	10.7	8.2	7.4	1.1
average		15.6	9.7	6.6	4.4	1.1
	100	80.3	22.1	10.2	3.1	1.9
	100	38.8	23.0	10.8	2.8	1.1
	average	59.6	22.6	10.5	3.0	1.5
20	100	53.2	33.6	16.5	6.1	0.9
10		43.4	18.5	11.1	9.5	1.4
10		44.9	15.0	7.9	2.1	1.1
average		44.2	16.8	9.5	5.8	1.3
20		74.8	19.6	3.7	1.9	1.1
20		36.2	21.6	12.7	8.5	1.1
average		55.5	20.6	8.2	5.2	1.1

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

The substance CAPA 203 was classified as readily biodegradable, having achieved 60% degradation within 7 days.

Executive summary:

A study was conducted to guideline OECD 301B using the substance CAPA 203. The reference compound (sodium acetate) degraded to 60% within 28 days. The total CO₂-evolution in the inoculum blank at the end of the test was 37 mg, which was below the maximum acceptable amount according to the guideline (40 mg CO₂L). The substance CAPA 203 was 60% degraded within 7 days when incubated at a concentration of 10 mg/L and 42% degraded when incubated at a concentration of 20 mg/L. On the basis of this result, CAPA 203 was classified as readily biodegradable.

Description of key information

One key study is presented. This study demonstrates that 2-oxepanone, polymer with 1,4-butanediol is readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater

Additional information

A reliable study was performed according to the OECD 301B guideline (Ready Biodegradability CO2 Evolution Test) using the test substance 2-oxepanone, polymer with 1,4-butanediol. Results showed 60% degradation of the test substance within 7 days when incubated at a concentration of 10 mg/L and 42% degradation when incubated at a concentration of 20 mg/L. On the basis of this result, the substance was classified as readily biodegradable.