1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)pentane

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:

4 Mar - 1 Apr 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Sumitomo 3M Ltd, lot #1
- Purity: 99.96%
- Synonyms: T-7869
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature in the dark

Oxygen conditions:

aerobic

Inoculum or test system:

other: secondary effluent

Details on inoculum:

- Source of inoculum/activated sludge: Secondary effluent freshly obtained from a municipal sewage treatment plant:
'Kurume central sewage treatment center, Fukuoka, Japan
- Preparation of inoculum for exposure: Secondary effluent was filtered through a No. 2 filter paper. The filtrate was kept aerated until inoculation.
- Inoculation level: One drop filtered effluent per liter

Duration of test (contact time):

28 d

Initial conc.:

10 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
- Test vessels: 100 mL in volume, sealed
- Composition of medium: Mineral medium, concentrations as per OECD 301D. Medium was pre-inoculated with one drop effluent per liter.
- Solubilising agent (type and concentration if used): None
- Test temperature: Incubator kept at 20 ± 1 °C
- pH adjusted: No
- Aeration: No, however each vessel was stirred continuously by magnetic stirrer

TEST SYSTEM
- Number of culture flasks/concentration: Two per day.
- Sampling frequency: Inoculum blank: day 0, 7, 14, 21 and 28; test substance, day 7, 14, 21, 28; reference substance: day 7 and 14 only. Test substance analysis by GC was done using separate test bottles from the DO measurement.
- DO analysis: Winkler oxygen method
- Test performed in closed vessels due to significant volatility of test substance: yes

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes, 10 bottles plus one additional for GC analysis on day 28 only
- Reference substance: Four bottles
- Abiotic sterile control: Two bottles for GC analysis only on day 28 (no DO measurement).
- Toxicity control: None

STATISTICAL METHODS:
ThOD and BOD calculated per OECD guidelines

Reference substance:

benzoic acid, sodium salt

Remarks:

(3.00 mg/L)

Key result

Parameter:

% degradation (O2 consumption)

Value:

0

Sampling time:

28 d

Parameter:

% degradation (test mat. analysis)

Value:

0

Sampling time:

28 d

Details on results:

Specific results on oxygen concentration and depletion are in Tables 1 and 2. In general, oxygen demand in vessels containing the test substance was less than in the procedural blank throughout the test. Essentially no biodegradation was observed.

After correction for matrix effects, 98-102% of applied test substance was recovered by GC from abiotic blanks and 100-104% recovered from test bottles.

Results with reference substance:

67% biodegradation of reference substance on day 7.

Table 1, Dissolved oxygen measurements at different points in time

Series	Flask	Oxygen	concentration	(mg O2/L)	after	x days
		day 0	day 7	day 14	day 21	day 28
Inoculum blank	A	8.94	8.90	8.80	8.68	8.37
	B	9.41	8.90	8.74	8.80	8.47
	mean	9.18	8.90	8.77	8.74	8.42
Procedure control	A	─	5.40	5.09	─	─
	B	─	5.72	5.13	─	─
	mean	─
Test substance	A	─	8.74	8.76	8.66	8.60
	B	─	8.76	8.86	8.74	8.41

 

Table 2, Mean values of oxygen depletion at different points in time

Series	Flask	Oxygen (% BOD)	depletion	(mg BOD/L)	after x days
		day 7	day 14	day 21	day 28
Procedure control	A	3.50 (70%)	3.68 (74%)	─	─
	B	3.18 (64%)	3.64 (73%)	─	─
Test substance, low	A	0.16 (2%)	0.01 (0%)	0.08 (1%)	0.00 (0%)
	B	0.14 (2%)	0.00 (0%)	0.00 (0%)	0.01 (0%)

Validity criteria fulfilled:

yes

Remarks:

O2 depletion in the inoculum blank was below 1.5 mg O2/l after 28 days, residual O2 in test bottles > 0.5 mg/l at any time, control substance degraded >60% within 14 days, differences of duplicate biodegradation values less than 20% as mg O2/L

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

HFE s-601 was not biodegraded in an OECD 301D test

Executive summary:

Biodegradation of HFE s-601 was assessed in a closed bottle test (OECD TG301D). Sodium benzoate was used as reference. HFE s-601 did not measurably degrade during the test period. In direct analysis by GC, HFE s-601 was recovered from biotic and abiotic test bottles at the same rate (ca. 100%). HFE s-601 is not readily biodegradable.

The study was conducted in accord with internationally accepted guidelines under GLP criteria. It is reliable without restriction and is suitable for use in Risk Assessment, Classification & Labelling, and PBT Analysis.

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 Dec 2003 - 13 Jan 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 D (Ready Biodegradability: Closed Bottle Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: 41-2601-2240-7 Lot #1
- Expiration date of the lot/batch: 30 Nov 2005
- Purity: 99.96%
- Synonyms: T-7869
STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature in the dark

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, predominantly domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Secondary effluent freshly obtained from a municipal sewage treatment plant:
'Waterschap de Maaskant','s-Hertogenbosch, The Netherlands
- Preparation of inoculum for exposure: Secondary effluent was filtered through a coarse filter paper, the first 200 ml was discarded. The filtrate was kept aerated until inoculation.
- Inoculation level: 4 mL/L, ca 1.2 mL in test bottles

Duration of test (contact time):

28 d

Initial conc.:

2 mg/L

Based on:

test mat.

Initial conc.:

5 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

TEST CONDITIONS
- Composition of medium: Mineral medium, concentrations as per OECD 301D
- Solubilising agent (type and concentration if used): None
- Test temperature: 19.5 °C to 20.5 °C (test probe in water bottle in same chamber)
- pH: 7.4 - 7.5 at test initiation
- pH adjusted: No
- Aeration of dilution water: Dilution water not used, mineral medium was left at room temperature overnight before test, DO concentration measured before test began to assure saturation.
- Continuous darkness: yes
- Other: Filtered effluent aerated until inoculation, ca. 1.0 - 1.2 mL added per test bottle.

TEST SYSTEM
- Culturing apparatus: ca. 250-300 mL BOD bottles with glass stoppers
- Number of culture flasks/concentration: Two per concentration per sampling day.
- Method used to create aerobic conditions: Aeration of medium before inoculation
- Measuring equipment: WTW Inolab Oxi Level 2 supplied with a WTW CellOx 325 oxygen electrode, electrolyte type ELY/G.
- Test performed in closed vessels due to significant volatility of test substance: yes

SAMPLING
- Sampling frequency: At day 0, 7, 14, 21 and 28. Bottles measured at the start were also measured on day 7. pH in sample bottles measured at start of test only.

CONTROL AND BLANK SYSTEM
- Inoculum blank: Yes (eight bottles)
- Abiotic sterile control: No
- Toxicity control: Yes (eight bottles), same amount of test and reference substances combined as in test substance low concentration (2 mg/L) and reference substance (2 mg/L) bottles separately.
- Reference substance: eight bottles

STATISTICAL METHODS:
ThOD and BOD calculated per OECD guidelines

Reference substance:

acetic acid, sodium salt

Remarks:

(2 mg/L)

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 0

Sampling time:

28 d

Remarks on result:

other: (range, -5 to 9% for low and high concentrations)

Details on results:

Specific results on oxygen concentration and depletion are in Tables 1 and 2. In general, oxygen demand in vessels containing the test substance was less than in the procedural blank throughout the test. Essentially no biodegradation was observed.

Results with reference substance:

55% biodegradation of reference substance on day 7.
Toxicity was assessed by comparison of toxicity test bottle BOD with sum of reference substance and low test substance BOD results. Little difference in oxygen consumption was observed (see Table 2), so the test substance was not considered to inhibit activated sludge.

Table 1, Dissolved oxygen measurements at different points in time

Series	pH at τ=0	Flask No.	Oxygen	concentration	(mg O2/L)	after	x days
			0	7	14	21	28
Inoculum blank	7.5	A	8.94	8.03	8.15	7.63	7.54
		B	9.00	7.93	8.19	7.41	7.64
		mean	8.97	7.98	8.17	7.52	7.59
Procedure control	7.4	A	9.10	7.23	7.06	6.87	6.41
		B	9.01	7.17	7.05	6.70	6.46
		mean	9.06
Test substance, low	7.4	A	9.06	8.51	8.24	7.99	7.61
		B	9.05	8.51	8.28	8.01	7.63
		mean	9.06
Test substance, high	7.4	A	9.04	8.64	8.43	7.98	7.77
		B	9.06	8.61	8.32	7.97	7.73
		mean	9.05
Toxicity control	7.4	A	9.10	7.43	7.16	7.00	6.84
		B	9.05	7.49	7.17	6.95	6.70
		mean	9.08

 

Table 2, Mean values of oxygen depletion at different points in time

Series	Flask	Oxygen	depletion¹	(mg BOD/L)	after x days
		day 7	day 14	day 21	day 28
Procedure control	A	0.835 (54%)	1.195 (77%)	0.735 (47%)	1.265 (81%)
	B	0.895 (57%)	1.205 (77%)	0.905 (58%)	1.215 (78%)
Test substance, low	A	-0.445²	0.015 (2 %)	-0.385²	0.065 (9%)
	B	-0.445²	-0.025²	-0.405²	0.045 (6%)
Test substance, high	A	-0.580²	-0.180²	-0.380²	-0.100²
	B	-0.550²	-0.070²	-0.370²	-0.060²
Toxicity control	A	0.655 (29%)	1.115 (49%)	0.625 (27%)	0.855 (37%)
	B	0.595 (26%)	1.105 (48%)	0.675 (29%)	0.995 (43%)

1, corrected for oxygen depletion in the blank control

2, %BOD not calculated when sample oxygen demand was less than inoculum blank

Validity criteria fulfilled:

yes

Remarks:

O2 depletion in the inoculum blank was below 1.5 mg O2/l after 28 days, residual O2 in test bottles > 0.5 mg/l at any time, control substance degraded >60% within 14 days, differences of duplicate biodegradation values less than 20% as mg O2/L

Interpretation of results:

under test conditions no biodegradation observed

Conclusions:

HFE s-601 was not biodegraded in an OECD 301D test

Executive summary:

Biodegradation of HFE s-601 was assessed in a closed bottle test (OECD TG301D). Sodium acetate was used as reference. HFE s-601 did not measurably degrade during the test period. In toxicity controls, HFE s-601 at a concentration of 2 mg/L did not measurably prevent the reference substance from being degraded. HFE s-601 is not readily biodegradable but is not toxic to activated sludge.

The study was conducted in accord with internationally accepted guidelines under GLP criteria. It is reliable without restriction and is suitable for use in Risk Assessment, Classification & Labelling, and PBT Analysis.

Description of key information

HFE s-601 is not biodegradable under conditions of a closed bottle test (OECD 301D)

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Type of water:

freshwater

Additional information

Biodegradation of HFE s-601 was assessed in two key studies done using a closed bottle method (OECD TG301D). In the first test, sodium acetate was used as reference. HFE s-601 did not measurably degrade during the test period. In toxicity controls, HFE s-601 at a concentration of 2 mg/L did not measurably prevent the reference substance from being degraded. In the second key test, sodium benzoate was used as reference.  No biodegradation of HFE s-601 was observed v. control.  In direct chemical analysis, measured concentrations of test substance did not change over the course of the test.  HFE s-601 was not biodegraded under conditions of either closed bottle test, but is not inhibitory to biodegradation.