3-methyl-2-pent-2-enylcyclopent-2-enone

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:

November 1997 - March 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to a recognised guideline and is GLP compliant.

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic, non-adapted

Details on inoculum:

Fresh activated sludge from a biological waste water treatment plant treating predominantly domestic sewage (City of Geneva, Aire) was used.
The sludge was collected in the morning, washed three times in the mineral medium (by centrifuging at 1000 g for 10 minutes, discarding the supernatant and resuspending in mineral medium) and kept aerobic until being used on the same day.

Duration of test (contact time):

31 d

Initial conc.:

100 mg/L

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

Test substance samples (25 mg, corresponding to 100 mgll in a 250-ml flask) were weighed in small aluminium boats and added directly to the test flasks of the SAPROMAT, whereas reference substance samples (sodium benzoate) were added as 1.0 ml of a 25 mglml solution in mineral medium.
All flasks were filled with 250 ml of mineral medium. Samples of test or reference substance, or both, were added. Then, a volume of suspended sludge corresponding to 7.5 mg dry weight (as determined from 3.6, generally 1 to 3 ml) was added.
About 2 g of soda lime was placed in an attachment of the stopper, the flasks were closed and placed in the water bath of the SAPROMAT. After temperature and pressure equilibration, the oxygen meters of the instrument were set to zero (time zero of the experiment).

Reference substance:

benzoic acid, sodium salt

Preliminary study:

Not applicable

Test performance:

Oxygen uptakes, as read on the SAPROMAT meters, were corrected by deducting the basic oxygen uptake of sludge and to account for differences between actual and nominal concentration of test and reference substances.
Degradation of sodium benzoate exceeded 40 % after 7 days and 65 % after 14 days: the activity of the inoculum is thus verified and the test is considered as valid.

Parameter:

% degradation (O2 consumption)

Value:

68

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

70

Sampling time:

31 d

Details on results:

Jasmone Cis underwent 68 % biodegradation after 28 days (70 % after 31 days) in the test conditions. Biodegradation started on day 17 after a long lag phase and reached 67 % at the end of the 10-day window (days 17 to 27).
Thus, Jasmone Cis should be regarded as readily biodegradable according to this test.
The curves obtained with the reference substance alone and with Jasmone Cis + reference substance showed no toxic effect of Jasmone Cis on the micro-organisms at the test concentration.

Results with reference substance:

Degradation of sodium benzoate exceeded 40 % after 7 days and 65 % after 14 days: the activity of the inoculum is thus verified and the test is considered as valid.

Table 1: Measured concentrations of test substance and reference substance and pH values

Flask No.	Concentrations (mg/L)		pH
	Test substance	Ref. Substance	Initial	Final
1/9	102.8	0	7.28	7.31
1/10	100.5	0	7.28	7.57
1/11	103.0	100.0	7.28	8.35
1/12	103.0	100.0	7.28	8.44
2/5	0	0	7.28	7.75
2/6	0	0	7.28	11.14*
2/7	0	100.0	7.28	8.28
2/8	0	100.0	7.28	11.15*

*Elevated pH values were due to a small leak of soda lime from the attachment of the stopper to the test flask. As oxygen consumption values are comparable with other replicates, this is not considered to have adversely affected the results.

Table 2: Biological oxygen demand and % degradation for test and reference substances

	Days	7	14	17	21	27	31
BOD Sludge	1^stflask	16.0	20.0	21.0	24.0	25.0	26.0
	2^ndflask	13.0	17.0	19.0	21.0	21.0	22.0
	mean	14.5	18.5	20.0	22.5	23.0	24.0
BOD Test Subs.	1^stflask	16.9	26.8	63.8	148.4	193.2	204.9
	2^ndflask	15.0	18.0	53.8	154.3	227.9	239.9
	1^stflask corrected	2.4	8.3	43.8	125.9	170.2	180.9
	2^ndflask corrected	0.5	9.5	33.8	131.8	204.9	215.9
% degr.	1^stflask	1	3	16	45	60	64
	2^ndflask	0	3	12	47	73	77
	mean	1	3	14	46	67	70

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Jasmone Cis underwent 68 % biodegradation after 28 days (70 % after 31 days) in the test conditions. Biodegradation started on day 17 after a long lag phase and reached 67 % at the end of the 10-day window (days 17 to 27).
Hence, Jasmone Cis is considered to be readily biodegradable according to this test.

Executive summary:

The Ready Biodegradability of Jasmone Cis was determined by the Manometric Respirometry Test according to the OECD Guidelines for Testing of Chemicals, Method No. 301 F. Jasmone Cis undergoes 68 % biodegradation after 28 days (70 % after 31 days) in the test conditions. Biodegradation starts on day 17 after a long lag phase and reaches 67 % at the end of the 10-day window (days 17 to 27). Thus, JASMONE CIS should be regarded as readily biodegradable according to this test. At the concentration used in the test (100 mg/l), Jasmone Cis is not inhibitory to the micro-organisms.

Reference 2

Endpoint:

biodegradation in water: screening tests

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

January 1992 - March 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP study, which has not been conducted to standard OECD guidelines for assessing inherent biodegradability (i.e. OECD 302 series). The standard inherent tests have a higher concentration of micro-organisms and hence offer a higher chance of detecting biodegradation than ready tests. In this study, ready test conditions were used and the test prolonged to 56 days, conditions which can only be indicative of inherent and ultimate biodegradability. Thus as an assessment for inherent biodegradability the study is rated as reliable with restrictions.

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Test extended to 56 days and modified by use of sealed vessels for assessment of volatile substances

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

Secondary effluent from an unacclimatised activated sludge plant at URL North. The inoculum used was 10% by volume of activated sludge plant secondary effluent. filtered through a Whatman filter paper (541) to remove coarse particulate matter. The level of dissolved inorganic carbon (DIC) was reduced by sparging the filtered effluent with nitrogen after prior adjustment of the pH to 6.5.

Duration of test (contact time):

56 d

Initial conc.:

10 mg/L

Based on:

other: Organic carbon

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

The test used was based on the sealed vessel test which is suitable for determining the ready and ultimate biodegradability of organic substances. However, by extending the test duration to 56 days from 28 days it is possible to obtain an indication of the inherent biodegradability of a substance. The test was conducted in 160 ml vessels (hypovials) containing 100 ml mineral salts medium inoculated with secondary effluent and the respective test or reference substance. Multiple vessels were prepared per substance sealed with a butyl rubber septum and an aluminium crimp seal. The headspace in each vessel had a volume of 60 ml and, when filled with air, contains approximately 6 times the mass of oxygen required for the complete oxidation of the substance.

The sealed vessels were incubated at 20°C on a rotary shaker and a single determination of the extent of biodegradation is made after 56 days. Firstly the concentration of carbon dioxide in the headspace gas is determined and then the seal was broken and the concentration of inorganic carbon in the test medium was determined. The total inorganic carbon in the vessel was calculated and corrected by subtracting the total inorganic carbon produced in a control. The control vessels were identical to the test vessels except for the omission of the test substance.

Preliminary study:

Not applicable

Test performance:

The air temperature during the 56 day test period was in the range of 14 - 22°C.

Key result

Parameter:

% degradation (CO2 evolution)

Value:

94.3

Sampling time:

56 d

Details on results:

Cis Jasmone was found to be 94.3% degraded after 56 days ( 95% CL = 31.1-157.6). Therefore, it is considered to be inherently biodegradable under the conditions of this test.

Results with reference substance:

No information provided

No further information on results provided.

Validity criteria fulfilled:

not specified

Interpretation of results:

inherently biodegradable, fulfilling specific criteria

Conclusions:

Cis Jasmone was found to be 94.3% degraded after 56 days ( 95% CL = 31.1-157.6). Therefore, it is considered to be inherently biodegradable under the conditions of this test.

Executive summary:

A study was conducted according to OECD 301B in order to determine the inherent biodegradability of a number of perfume ingredients, including Jasmone Cis, in a sealed vessel test. Test vessels containing a nominal 10 mg/L organic carbon of Jasmone Cis were inoculated with secondary effluent and incubated at 20^oC for 56 days. The concentration of carbon dioxide in the headspace was determined on day 56

Cis Jasmone was found to be 94.3% degraded after 56 days ( 95% CL = 31.1-157.6). Therefore, it is considered to be inherently biodegradable under the conditions of this test.

Reference 3

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

February 1991 - March 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Although a GLP compliant study conducted according to OECD Guidelines, there were a number of deficiencies in the study. There was variability between replicates, an anomalous mean value was obtained at 24 days and, for technical reasons, the final result was based only on 4 vessels as opposed to the standard 5. However, based on the results at day 14-21 and day 28 the substance could be classified as readily biodegradable. Thus the study is considered reliable with restrictions.

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

modified by use of sealed vessels for assessment of volatile substances

GLP compliance:

yes

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not applicable

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The inoculum used was 10% by volume of activated sludge plant secondary effluent, filtered through a Whatman filter paper (541) to remove coarse particulate matter. The level of dissolved inorganic carbon (DIC) was reduced by sparging the filtered effluent with nitrogen after prior adjustment of the pH to 6.5.

Duration of test (contact time):

28 d

Initial conc.:

10 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

The test is conducted in 160 ml vessels (hypovials) containing 100 ml mineral salts medium inoculated with secondary effluent and the respective test or reference substance. Multiple vessels are prepared per substance sealed with a butyl rubber septum and an aluminium crimp seal. The headspace in each vessel has a volume of 60 ml and, when filled with air, contains approximately 6 times the mass of oxygen required for the complete oxidation of the substance.
The sealed vessels are incubated at 20°C on a rotary shaker. At intervals during the 28 day test period a vessel is removed and concentration of carbon dioxide in the headspace gas determined. The seal is then broken and the concentration of inorganic carbon in the test medium is also determined. The total inorganic carbon in the vessel is calculated and corrected by subtracting the total inorganic carbon produced in a control. The control vessels are identical to the test vessels except for the omission of the test substance. From a knowledge of the initial organic carbon concentration added as test substance, the extent of mineralisation can be determined.

Preliminary study:

Not applicable

Test performance:

The air temperature during the 28 day test period was in the range of 16 - 23°C. The temperature of the liquid medium in the vessels during the 28 day test period was in the range of 18.5 - 25°C.

Parameter:

% degradation (CO2 evolution)

Value:

60

Sampling time:

28 d

Details on results:

The biodegradation of Cis jasmone exhibited a significant lag period and was quite variable. However, Cis jasmone was classified as readily and ultimately biodegradable on the basis of the results obtained on day numbers 14 - 21 and because the mean biodegradation on day 28 was 60%.

Results with reference substance:

Not stated.

Table 1: Percentage biodegradation of test substance

Day No.	4	7	10	14	18	21	24	28	95% CL
% biodegradation	-1.1	-3.8	-5.2	-5.2	25.3	61.0	40.3	60.0	43.8-76.1

The reported 95% CL indicates that comparable results between replicates (defined as < 20% difference) was not obtained.

The 28 day final analysis was based on 4 vessels as opposed to the standard 5. This was because the analyser malfunctioned on day 3 and a repeat analysis on day 4 meant that another vessel was sacrificed. Thus at the end of the study the number of vessels left for analysis was one short.

Validity criteria fulfilled:

not specified

Interpretation of results:

readily biodegradable

Conclusions:

Based on the results of the study Jasmone Cis is considered to be readily biodegradable.

Executive summary:

A study was conducted according to OECD 301B in order to determine the ready and ultimate biodegradability of a number of perfume ingredients, including Jasmone Cis, in a sealed vessel test. Test vessels containing a nominal 10 mg/L of Jasmone Cis were inoculated with secondary effluent and incubated at 20 ^oC for 28 days. The concentration of carbon dioxide in the headspace was determined on day 4, 7, 10, 14, 18, 21, 24, and 28.

The biodegradation of Cis jasmone exhibited a significant lag period and was quite variable. However, Cis jasmone was classified as readily and ultimately biodegradable on the basis of the results obtained on day numbers 14 - 21 and because the mean biodegradation on day 28 was 60%. Based on the results of the study Jasmone Cis is considered to be readily biodegradable.

Description of key information

Readily biodegradable (68% after 28 d, OECD 301 F)

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Additional information

Three studies are available, in which the ready biodegradability of (Z)-3-methyl-2-(pent-2-en-1-yl)cyclopent-2-enone (CAS 488-10-8) was assessed according to internationally accepted OECD guidelines and GLP.

In the key study, a Manometric Respirometry Test was conducted according to OECD 301 F in which a nominal concentration of 100 mg/L test item was inoculated with activated sludge (7.5 mg dw in 0.25 L) for 31 d. A blank control, toxicity control and reference substance were run in parallel. The evolved carbon dioxide in the respirometer flasks was trapped with soda lime pellets and the biological oxygen consumption (BOD) was continuously quantified. Biodegradation was expressed as percent oxygen demand (measured, blank corrected) of the theoretical oxygen demand (ThOD, calculated).

Biodegradation started on Day 17 after a long lag phase and reached 67% by the end of the 10-day window (Days 17 – 27). Biodegradation reached 68% after 28 d and 70% after 31 d. The reference substance confirmed the suitability of the inoculum and the test item was not inhibitory to microorganisms of activated sludge at the tested concentration. Thus, (Z)-3-methyl-2-(pent-2-en-1-yl)cyclopent-2-enone (CAS 488-10-8) is readily biodegradable according to OECD guideline criteria.

The results of the two supporting studies, in which CO2 Evolution Tests were conducted according to standard and modified OECD guideline 301 B, respectively, confirm the ready biodegradability of (Z)-3-methyl-2-(pent-2-en-1-yl)cyclopent-2-enone (CAS 488-10-8).

In the supporting study according to the standard OECD guideline 301 B dating from 1995, 10 mg/L test item was inoculated with activated sludge for 28 d in sealed hypovials. The concentration of carbon dioxide in the headspace was determined on Day 4, 7, 10, 14, 18, 21, 24, and 28. After 28 d, the mean biodegradation reached 60%.

Similarly, in the supporting study according to the modified OECD guideline 301B dating from 1993, 10 mg/L test item was inoculated with activated sludge for and extended test period of 56 d. After 56 d biodegradation reached 94.3%, indicating that the substance is inherently biodegradable.