Bicyclo[3.1.1]hept-2-ene-2-ethanol, 6,6-dimethyl-, 2-acetate, (1R,5S)-

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:

19 December 1996 – 17 January 1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study meets OECD Guideline No 301F requirements.

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Principles of method if other than guideline:

not applicable

GLP compliance:

yes

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

Source of activated sludge: biological waste water treatment plant treating predominantly domestic sewage (City of Geneva, Aire)

Preconditioning: the sludge is collected in the morning, washed three times in the mineral medium (by centrifuging at 1000 g for 10 min, discarding the supernatant and resuspending in mineral medium) and kept aerobic until being used on the same day.

Dry weight of suspended solids: 3.793 g/L

Concentration of sludge: 30 mg dw/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: the following stock solutions were prepared
Solution A: KH2PO4: 8.5 g/L, K2HPO4: 21.75 g/L, Na2HPO4.2H2O: 33.4 g/L, NH4Cl: 0.5 g/L
Solution B: CaCl2: 27.5 g/L
Solution C: MgSO4.7H2O: 22.5 g/L
Solution D: FeCl3.6H2O: 0.25 g/L, HCl conc.: one drop
Mineral medium was prepared by mixing 50 mL of solution A and 2000 mL of deionized water, adding 5 mL of each of the solutions B, C and D and making up to 5 L with deionized water.
- Source/preparation of dilution water: deionized water containing less than 10 mg/L dissolved organic carbon
- Test temperature: 22 °C

TEST SYSTEM
- Culturing apparatus: flasks of the volumetric respirometer (SAPROMAT)
- Number of culture flasks/concentration: two
- Details of trap for CO2 if used: evolved CO2 was absorbed by sodalime pellets

MEASURING EQUIPMENTS:
- Respirometer: SAPROMAT D 12 (J. M. VOITH GmbH, Heidenheim, Germany)

SAMPLING
- Sampling frequency: everyday the oxygen consumption of each flask was recorded and correct temperature and stirring were checked. At the end of the test period (normally 28 days), the pH of each flask was measured again.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes; containing inoculum only
- Procedure control: yes; containing reference substance (aniline) with inoculated medium
- Toxicity control: yes; containing test material and reference substance (sodium benzoate) with inoculated medium

Reference substance:

benzoic acid, sodium salt

Remarks:

100 mg/L; purity: min. 99.0 %; source: Fluka, Switzerland

Preliminary study:

no data

Test performance:

no data

Key result

Parameter:

% degradation (O2 consumption)

Value:

78

Sampling time:

28 d

Details on results:

Initial test material concentration: 100 mg/L

Theoretical oxygen demand (ThOD) = 2.61 mg O2/mg

% biodegradation on Day 7: > 10 %

% biodegradation on Days 17 > 60 %

% biodegradation on Days 28 = 78 %

Results with reference substance:

Theoretical oxygen demand (ThOD) = 1.67 mg O2/mg

% biodegradation on Day 5: > 60 %

% biodegradation on Days 14 = 83 %

Table 5.2.1/2: Test material: Biological Oxygen Demand (BOD, mg O2/L, adjusted to nominal concentrations)

 

Days			5	7	14	17	21	28
BOD Sludge	1st flask	B1	22.0	23.0	31.0	32.0	37.0	42.0
	2nd flask	B2	22.0	23.0	30.0	31.0	37.0	44.0
	mean	B	22.0	23.0	30.5	31.5	37.0	43.0
BOD Test substance	1st flask	C1	39.3	42.1	176.2	207.6	240.9	245.6
	2nd flask	C2	39.4	77.6	177.1	217.3	242.2	248.9
	1st flask corrected	C1-B	17.3	19.1	145.7	176.1	203.9	202.6
	2nd flask corrected	C2-B	17.4	54.6	146.6	185.8	205.2	205.9
% Degradation	1st flask	D1	7	7	56	67	78	78
	2nd flask	D2	7	21	56	71	79	79
	mean	D	7	14	56	69	78	78

B = (B1 + B2) /2;

D1 = 100*(C1 - B)/ThOD*[S]; D2 = 100*(C2 - B)/ThOD*[S]; D = (D1 + D2)/2

[S]: Initial test substance concentration (mg/L)

 

 

Table 5.2.1/3: Reference substance (sodium benzoate): Biological Oxygen Demand (BOD, mg O2/L, adjusted to nominal concentrations)

 

Days			5	7	10	14	21	28
BOD Sludge	1st flask	B1	22	23	26	31	37	42
	2nd flask	B2	22	23	24	30	37	44
	mean	B	22	23	25	30.5	37	43
BOD reference substance	1st flask	A1	143	152.9	164.9	172.9	184.9	195.9
	2nd flask	A2	136	145	154.9	163.9	171.9	178.9
	1st flask corrected	A1-B	121	129.9	139.9	142.4	147.9	152.9
	2nd flask corrected	A2-B	114	122	129.9	133.4	134.9	135.9
% Degradation	1st flask	D1	73	78	84	86	89	92
	2nd flask	D2	68	73	78	80	81	82
	mean	D	71	76	81	83	85	87

B = (B1 + B2)/2;

D1 = 100*(A1 - B)/ThOD*[S]; D2 = 100*(A2 - B)/ThOD*[S]; D = (D1 + D2)/2

[S]: Initial test substance concentration (mg/L)

Validity criteria fulfilled:

yes

Remarks:

% degradation in reference material reached the pass levels by Day 14; oxygen uptake of inoculum blank was < 60 mg O2/L; pH of the test solutions at the end of the test was 7.40-7.44; toxicity control showed no toxicity to microorganisms

Interpretation of results:

readily biodegradable

Conclusions:

Nopyl acetate was readily biodegradable in a test carried out according to OECD Guideline No 301 F.

Executive summary:

In a ready biodegradation study performed according to OECD Guideline No 301 F and GLP, nopyl acetate was tested at a concentration of 100 mg/L and the inoculum was activated sewage sludge, domestic. The degradation of the test material was assessed by the determination of the oxygen consumption. The test treatments, inoculum blank, procedure control and toxicity control were measured in duplicates.

 

At 100 mg/L test concentration, greater than 10 % degradation was reached on Day 7 and greater than 60 % biodegradation was reached on Day 17. The pass level for ready biodegradability was reached in the required 10-d window within the 28-d period of the test: 78% degradation on Day 28.

 

The reference material (sodium benzoate) reached greater than 60 % biodegradation within 5 days. The biodegradation curves obtained with the reference substance alone and with test material+reference substance show no toxic effect on the micro-organisms. Hence, it met the validity criteria for reference material and toxicity control.

 

Therefore, nopyl acetate was readily biodegradable.

Description of key information

Screening for ready biodegradability was performed by a manometric respiratory test.
Nopyl acetate is readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Key study conducted according to OECD 301 F Guideline and GLP without deviation.

Nopyl acetate was tested at a concentration of 100 mg/L. The inoculum derived from domestic sewage sludge. Degradation was assessed by measurement of oxygen consumption.

The pass level for ready biodegradability was reached in the required 10-d window within the 28-d period of the test: 78% degradation on Day 28. This result can be used as key value for chemical safety assessment.