1,1,2,2,3,3,4-heptafluorocyclopentane

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

biodegradation in water: inherent biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 2008-08-30 to 2008-10-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study performed to current OECD guidelines with no significant deviations.

Qualifier:

according to guideline

Guideline:

OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II))

Version / remarks:

1981

Deviations:

no

GLP compliance:

no

Remarks:

Non GLP, but in accordance with CMA (China Metrology Accreditation), CNAS (China National Accreditation Service for Conformity Assessment) experimental conditions.

Specific details on test material used for the study:

Batch No.: 7101801
Purity: >97%

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Activated sludge, surface soil and surface water were sampled from ten sites such as Nanjing Suojincun, Chengbei, Baguazhou and Hexi distributing in four districts throughout Nanjing city. 1 L of the sludge, soil, water was collected respectively and mixed thoroughly together.
- Method of cultivation: After removing floating matter and allowing standing, adjust the supernatant to pH 7.0 with sodium hydroxide or phosphoric acid. Used an appropriate volume of the filtered supernatant to fill a fill-and-draw activated sludge vessel and aerated the liquid for about 23.5 h. Thirty minutes after stopping aeration, discarded about one third of the whole volume of supernatant and added an equal volume of a solution (pH 7.0) containing 0.1 % each of glucose, peptone and potassium orthophosphate, to the settled material and re-commence aeration. Repeated this procedure once per day until was used.
- Preparation of inoculum for exposure: The mixture was allowed to stand, and the supernatant was removed before use. Taken a small quantity of sludge to centrifuge (10000 rpm x 10 min) and then weigh. Oven the sludge dry and weigh again in order to calculate the content of dry sludge. Take a certain amount of centrifuged sludge to dilute with basal culture medium to activated sludge suspension with a concentration of 100 mg/L (dry basis).
- Concentration of sludge: 100 mg/L (dry basis)

Duration of test (contact time):

28 d

Initial conc.:

30 mg/L

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: The dilution medium was prepared by adding 3 mL of each of the following stock solutions, prepared in pre-aerated pure water to each litre of pure water.
Stock solution A: KH2PO4 (potassium dihydrogen phosphate) 8.50 g/L, K2HPO4 (dipotassium hydrogen phosphate) 21.8 g/L, Na2HPO4.2H2O (disodium monohydrogen phosphate dihydrate) 22.2 g/L, NH4Cl (ammonium chloride) 1.7 g/L, The pH of this solution was 7.2.
Stock solution B: CaCl2 (Calcium chloride) 27.5 g/L
Stock solution C: MgSO4.7H2O (magnesium sulphate heptahydrate) 22.5 g/L
Stock solution D: FeCl3.6H2O (iron (III) chloride hexahydrate) 0.025 g/L
- Test temperature: 25 ± 1 °C
- Concentration of activated sludge: 100 mg/L (W/V)
- Aeration of dilution water: Stirvigorously with mechanical stirrer
- Continuous darkness: yes

TEST SYSTEM
- Culturing apparatus: Incubator
- Measuring equipment: pH-electrodes, BOD meter
- Test procedure: The test substance was added to the vessels designated "test" to give the required final test concentration (30 mg/L). The reference substance (aniline) was added to the "reference" vessels to give a final concentration of 100 mg/L Each prepared solution was then transferred to the required number of BOD bottles (two "reference", two "control", and two "test" ). Added test micro-organisms to above BOD bottles except "abiotic" bottle, and the concentration of supernatant is 100 mg (dry basis)/L. Finally six BOD bottles were made up to 300 mL with the dilution medium.
Assembled the equipment, checked that it is air-tight, began the stirrers, and started the measurement of oxygen uptake under conditions of darkness.
Checked the temperature, stirrer and recorder, and noted any changes in colour of the contents of the vessels on a daily basis. Read the BOD for the six bottles directly by an appropriate method at the days of 5, 7, 11, 14, 18, 21, 25 and 28d.

Reference substance:

aniline

Key result

Parameter:

% degradation (O2 consumption)

Value:

14.4

Sampling time:

28 d

Parameter:

% degradation (O2 consumption)

Value:

6.4

Sampling time:

14 d

Results with reference substance:

The level of biodegradation of the reference substance exceeded 40% after 7 days, and 65% after 14 days.

Validity criteria fulfilled:

yes

Interpretation of results:

not inherently biodegradable

Conclusions:

The biodegradation of the test item was 6.40% after 14 days, 14.4% after 28 days. Therefore, the test item is not inherently biodegradable in this test condition.

Executive summary:

This test was to determine the inherent biodegradability of organic chemicals in an aerobic, aqueous medium according to OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II)).

Test solutions were prepared in an inorganic salts medium, inoculated with a number of micro-organisms from not less than 10 places throughout Nanjing city, and kept in BOD bottles in the dark at a temperature of 25 ± 1 °C. "Abiotic", "reference" and "control" were set up simultaneity, while "abiotic" contained inoculated mineral salts medium and a measured amount of test substance, "reference" contained inoculated mineral salts medium and a measured amount of a reference substance. And that "control" only contained inoculated mineral salts medium.

 

During the test, the temperature kept at 25 ± 1 °C. The test was valid because the level of biodegradation of the reference substance exceeded 40% after 7 days, and 65% after 14 days.

The biodegradation of the test item was 6.40% after 14 days, 14.4% after 28 days. Therefore, the test item is not inherently biodegradable in this test condition.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 1997-07-08 to 1997-07-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I))

Version / remarks:

Revised July 17, 1992

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

Lot No.: 9704-2A
Purity: 98.17%

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic (adaptation not specified)

Details on inoculum:

- Sampling sites: 10 locations in Japan
- Sludge sampling method:
(1) City sewage: Return sludges from sewage plants were collected.
(2) Rivers, lake and sea: Surface water and surface soil which are in contact with the atmosphere were collected.
- Mixing of fresh and old activated sludge:
The filtrate (5 L) of the supernatant of the activated sludge used at that time was mixed all together with each of the filtrate (500 mL) of the supernatant of a newly
collected sludge (10 sources). The mixed filtrate (10 L) was aerated sufficiently through prefiltered open-air, after the pH value of the mixture was adjusted to 7.0 ± 1.0.
- Cultivation:
In about 30 minutes after ceasing the aeration of the sludge mixture, supernatant corresponding to about 1/3 of the whole volume was removed. Then an equal volume of dechlorinated water was added to the remaining portion. This mixture was aerated, and then a previously decided amount of synthetic sewage was added to the mixture so that the concentration of the synthetic sewage was 0.1 (W/V)% in the volume of the dechlorinated water added. This procedure was repeated once every day. The cultivating was carried out at 25±2°C.
- Concentration of suspended solid: 2400 mg/L.

Duration of test (contact time):

28 d

Initial conc.:

100 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Parameter followed for biodegradation estimation:

test mat. analysis

Details on study design:

TEST CONDITIONS
- Composition of medium: Each 3 mL of solution A, B, C and D, which are prescribed in JIS K 0102-1993-21, were made up to 1000 mL with purified water, and then the pH of this solution was adjusted to 7.0.
- Test temperature: 25 ± 1°C
- pH adjusted: no
- CEC (meq/100 g):
- Suspended solids concentration: 30 mg/L

TEST SYSTEM
- Culturing apparatus: 300 mL in volume (improved type for a volatile matter)
- Number of culture flasks/concentration:
(1) Addition of test substance or aniline
(a) The test solution (water + test substance) (n=1, Vessel No.2)
In one test vessel, 19.0 μL (30 mg) of the sample was added into 300 mL of purified water
(b) The test solution (sludge + test substance) (n=3, Vesel No.1, 3 and 4)
In each test vessel, 19.0 μL [30 mg] of the sample was added into the basal culture medium (300 mL -a volume of the activated sludge inoculated)
(C) The test solution (sludge + aniline) (n=1, Vessel No.5)
In one test vessel, 29.5 μL [30 mg] of aniline was added into the basal culture medium (300 mL - a volume of the activated sludge inoculated)
(d) The test solution (control blank) (n=1, Vessel No.6)
In one test vessel, nothing was added to the basal culture medium (300 mL - a volume of the activated sludge inoculated).
(2) Inoculation of activated sludge
The activated sludge cultivated was added to each test vessel (b), (C) and (d), so that the concentration of the suspended solid reached 30 mg/L
- Measuring equipment: Closed system Oxygen consumption measuring apparatus
- Test performed in closed system: yes

SAMPLING
- Sampling frequency: 28d, after the termination of the cultivation

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: yes
- Toxicity control: yes

Reference substance:

aniline

Test performance:

Percentage biodegradations of aniline calculated by the BOD values was 70 % and 91 % at the 7 and 14th day, respectively. It was concluded that this test conditions were valid.

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Parameter:

% degradation (test mat. analysis)

Value:

2

Sampling time:

28 d

Results with reference substance:

70% degradation after 7 days
91% degradation after 14 days
100% degradation after 21 days
100% degradation after 28 days

Validity criteria fulfilled:

yes

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

The test substance was not biodegraded by microorganisms under the present test conditions.

Executive summary:

This test was performed to evaluate the biodegradability of test item by microorganisms in accordance with OECD301C.

100 mg/L test substance and 30 mg/L activated sludge were cultured at 25°C for 28 days. Percentage biodegradation were determined to be 0% and 2% by BOD or GC, respectively.Therefore, the test substance was not biodegraded by microorganisms under the present test conditions.

Description of key information

Ready biodegradability:

This test was performed to evaluate the biodegradability of test item by microorganisms in accordance with OECD301C. Percentage biodegradation were determined to be 0% and 2% by BOD or GC, respectively.Therefore, the test substance was not biodegraded by microorganisms under the present test conditions.

Inherent biodegradability:

This test was to determine the inherent biodegradability of organic chemicals in an aerobic, aqueous medium according to OECD Guideline 302 C (Inherent Biodegradability: Modified MITI Test (II)).

The biodegradation of the test item was 6.40% after 14 days, 14.4% after 28 days. Therefore, the test item is not inherently biodegradable in this test condition.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater