Potassium (1R,3R)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylate and Potassium (1S,3S)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylate

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 October 1995 to 16 November 1995

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

reaction mass of (1R,3R)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylic acid and (1S,3S)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylic acid

EC Number:

614-283-9

Cas Number:

68127-59-3

Molecular formula:

C9H10ClF3O2

IUPAC Name:

reaction mass of (1R,3R)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylic acid and (1S,3S)-3-[(1Z)-2-chloro-3,3,3-trifluoroprop-1-en-1-yl]-2,2-dimethylcyclopropanecarboxylic acid

Test material form:

not specified

Details on test material:

- Physical state: White solid.
- Storage condition of test material: In original container, at ambient temperature in the dark.

Specific details on test material used for the study:

The test sample was stored in the dark at ambient temperature, until required for testing.

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Obtained from a sewage treatment plant on 11th October 1995. Sludge was aerated in the laboratory until use.
- Preparation of inoculum for exposure: 500 mL of sludge was washed by centrifuging and decanting the supernatant. The supernatant was replaced with test medium. This process was repeated.
- Pretreatment: The 93 mL of washed inoculum was finally prepared by diluting up to 10 L with additional test medium. Aliquots were then added to culture bottles, where they were further diluted with either the reference substance or deionised water. The cultures were then stirred for 6 days to condition the sludge prior to study initiation.
- Concentration of sludge: Each test bottle contained a nominal activated sludge concentration of 30 mg/L.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

50 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation 1

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation 2

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: The test medium contained the following nutrients per litre of deionised water: KH2PO4, 85 mg; K2HPO4, 217.5 mg; Na2HPO4.2H2O, 334 mg; MgSO4.7H2O, 22.5 mg; FeCl3.6H2O, 0.25 mg; NH4Cl, 5.0 mg; CaCl2.2H2O, 36.4 mg and EDTA disodium salt, 0.4mg.
- Test temperature: Nominal test temperature 20 ± 2 ºC
- pH: Was measured in all samples on Day 28 and ranged from 7.2 to 7.6.
- pH adjusted: No
- Suspended solids concentration: Filterable solids 3601 mg/L.(prior to dilution)
- Continuous darkness: Yes.
- Continuous stirring: Yes.

TEST SYSTEM
- Culturing apparatus: A dark 500 mL glass culture bottle with a magnetic stirrer was used; this was connected to a closed mercury manometer.
- Number of culture flasks/concentration: Six replicate flasks were set up for each concentration.
- Method of addition of test material: A specific volume of the test material was added to samples of conditioned culture medium to achieve the desired test concentrations, see Table 1.
- Measuring equipment: Oxygen uptake by microbial respiration was measured by means of a biochemical oxygen demand (BOD) apparatus. The decrease in pressure, resulting from used oxygen and evolved carbon dioxide being absorbed, was measured directly on a scale of the manometer calibrated in mgO2/L.
- Test performed in closed vessels: Closed system.
- Details of trap for CO2 and volatile organics if used: A potassium hydroxide trap was used in a sealed cup in the neck of each bottle.

CONTROL AND BLANK SYSTEM
- Inoculum blank: Three replicates containing conditioned culture medium and deionised water.
- Positive control: Three replicates, containing conditioned culture medium and the reference substance served as an inoculum viability check.
- Abiotic sterile control: Three culture flasks were set up containing the test material in conditioned culture medium, which were then poisoned with mercuric chloride.
- Other: See Table 1.

EFFECT PARAMETERS

- Biological Oxgen Demand: The decrease in pressure as oxygen was used, and carbon dioxide was evolved (and absorbed in the attached CO2 traps) was read directly on the manometer attached to the culture bottles (calibrated in mg O2/L).

- Chemical Oxygen Demand, COD
Method: Titrimetric endpoint determination procedure. A known amount of the test material was refluxed with an excess of acidifies potassium dichromate in the presence of silver sulphate and chromium III ions. After cooling, the excess dichromate was titrated with ferrous ammonium sulphate using an autotitration system.

- Carbon Analysis, DNPOC
Selected cultures: The blank control, reference substance and three of each test concentration were selected for DNPOC analysis.
Method: Bottles were centrifuged on Day 28 and the supernatant removed for analysis. The content of the control bottles was pooled and samples provided for analysis. Samples were first acidified and purged to remove any inorganic carbon. The remaining carbon was then oxidised to carbon dioxide and quantified by a non-dispersive infra-red detector.

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

< 5

Sampling time:

28 d

Remarks on result:

other: At both concentrations tested

Details on results:

28 Day BOD at a concentration of 50 mg/L < 0.1 g O2/g, which corresponds to < 15% of it's COD
28 Day BOD at a concentration of 100 mg/L < 0.05 g O2/g, which corresponds to < 10% of it's COD

BOD5 / COD results

BOD5 / COD

Key result

Parameter:

COD

Value:

0.79 g O2/g test mat.

Results with reference substance:

28BOD = 0.56 g O2/g which corresponds to 81% of it's COD
COD measured = 0.69 g O2/g
COD theoretical = 0.68 g O2/g
These results confirmed the viability of the test, by confirming that the sludge contained viable organisms.

Any other information on results incl. tables

Carbon Analysis, DNPOC

The results of DNPOC analysis show that, for the 50 and 100 mg/L nominal concentrations test groups, after blank correction, 24 and 49 mg/L of the carbon remained at 28 days, respectively. This corresponds to a <5% loss of carbon over the test period at both concentrations. Results can be seen in Table 3.

Table 2. BOD Results

Flask Content		Time (days)
		5	10	15	20	25	28
Blank Control	Replicates	4.5	7.0	7.5	7.5	7.5	8.0
		4.0	6.0	6.0	6.0	6.0	6.0
		5.0	7.0	8.0	8.0	8.0	8.0
	Mean value (mgO2/L)	4.5	6.5	7.0	7.0	7.0	7.5
Reference Substance	Replicates	105	115	115	115	115	115
		105	120	120	120	120	120
		105	115	115	120	120	120
	Mean blank corrected BOD (mgO2/L)	100.5	110.0	109.5	111.5	111.5	111.0
	BOD (gO2/g)	0.50	0.55	0.55	0.56	0.56	0.56
	% Biodegradability (BOD/COD%)	72	80	80	81	81	81
Test Material 50 mg/L	Replicates	<5	5	5	5	5	5
		5	5	5	5	5	5
		5	5	5	5	5	5
		<5	<5	<5	<5	<5	<5
		<5	<5	<5	<5	<5	<5
		<5	<5	<5	<5	<5	<5
	Mean blank corrected BOD 28 (mgO2/L)	<5	<5	<5	<5	<5	<5
	BOD 28 (gO2/g)	<0.01	<0.01	<0.01	<0.01	<0.01	<0.01
	% Biodegradability (BOD/COD%)	<15	<15	<15	<15	<15	<15
Test Material 100 mg/L	Replicates	<5	<5	<5	<5	<5	<5
		<5	<5	<5	<5	<5	<5
		<5	5	5	<5	<5	<5
		<5	<5	<5	<5	<5	<5
		<5	<5	<5	<5	<5	<5
		<5	<5	<5	<5	<5	<5
	Mean blank corrected BOD 28 (mgO2/L)	<5	<5	<5	<5	<5	<5
	BOD 28 (gO2/g)	<0.05	<0.05	<0.05	<0.05	<0.05	<0.05
	% Biodegradability (BOD/COD%)	<10	<10	<10	<10	<10	<10
Sterile Control	Replicates	<5	<5	<5	<5	<5	<5
		<5	<5	<5	<5	<5	<5
		<5	<5	<5	<5	<5	<5
	Mean blank corrected BOD 28 (mgO2/L)	<5	<5	<5	<5	<5	<5
	BOD 28 (gO2/g)	<0.05	<0.05	<0.05	<0.05	<0.05	<0.05
	% Biodegradability (BOD/COD%)	<10	<10	<10	<10	<10	<10

 

Table 3. 28 Day Dissolved Non-Purgeable Organic Carbon (DNPOC) Results

Flask Content		DNPOC	Blank corrected DNPOC	% carbon loss
Blank Control	Replicates	-	-	-
		1.2	-	-
		1.2	-	-
	Mean	1.2	-	-
Reference Substance	Replicates	2.0	0.8	93
		1.8	0.6	99
		1.8	0.6	99
	Mean	1.9	0.7	97
Test Material 50 mg/L	Replicates	25	24	<5
		23	22	<5
		27	26	<5
	Mean	25	24	<5
Test Material 100 mg/L	Replicates	49	48	<5
		51	50	<5
		49	48	<5
	Mean	50	49	<5

Table 4. Verification of Test Concentration by Liquid Chromatography

Nominal Concentration of Test Material (mg/L)		Measured Concentration of Test Material (mg/)
		Day 28	% of nominal
Blank Control		< 0.02	-
50		50	100
		50	100
		49	98
	Mean	50	99
100		102	102
		97	97
		98	98
	Mean	99	99
Sterile Control		95	95
		102	102
		97	97
	Mean	98	98

Limit of determination 0.02 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

Under the conditions of the test, the BOD value for the test material after 28 days indicated negligible biodegradation (< 5 %) and therefore the test substance can be classified as not readily biodegradable. The study is considered to be reliable, relevant and adequate for risk assessment and classification and labelling purposes.

Executive summary:

The ready biodegradability of the test material was determined in accordance with the standardised guidelines OCED 301 F by the measurement of biochemical oxygen demand (BOD) in a manometric respirometric test. The BOD value for the test material after 28 days indicated negligible biodegradation (< 5 %), and therefore the test substance can be classified as not readily biodegradable.

The results obtained from the reference substance confirm the viability of the test, by confirming that the sludge contained viable organisms. The results from DNPOC analysis showed that <5% of carbon was lost over the study period at both concentrations. Verification of the test concentration showed that samples were 95-102% of the nominal concentration on Day 28, confirming that the test material did not undergo any structural changes over the study period.