Isodecyl pivalate

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions (temperature was not in the range as recommended in the guideline).

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Test was conducted at room temperature and not under controlled temperature of 22 ± 2 °C

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Sewage treatment plant Wavre, France (2nd stage)
- Laboratory culture: No
- Initial cell/biomass concentration: > 10^6 CFU/mL (Verification with Sanicheck)

Duration of test (contact time):

28 d

Initial conc.:

ca. 20 mg/L

Based on:

other: TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: 4 mL Fe Chloride solution, 1 mL Mg Sulphate solution, 1 mL Ca Chloride solution, 2 mL Phosphate solution in 1 L of High Quality Water (Water containing a tiny amount of carbon < 2.0 mg/L, no toxic substances and a resistivity > 18)
- Test temperature: 23.6 - 26.4 °C
- pH: 7.31 - 7.40
- pH adjusted: no

TEST SYSTEM
- Culturing apparatus: Red containers of 5 L
- Number of culture flasks/concentration: 4
- Method used to create aerobic conditions: The system was purged with air containing no CO2 for 24 h before adding sample.
- Test performed in open system: No
- Details of trap for CO2 and volatile organics if used: 100 mL flasks to absorb CO2 in a barium hydroxide (Ba(OH)2) solution.

SAMPLING
- Sampling frequency: Samples were taken on day 2, 5, 9, 13, 16, 21 and 28.
- Sampling method: The closest to the container flask containing Ba(OH)2 was removed and a new one was added to the end of the queue. The closest to the container flask containing Ba(OH)2 was removed and a new one was added to the end of the queue. The barium hydroxide solution was titrated with 0.05 M HCl using phenolphthalein as the indicator.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes
- Abiotic sterile control: no
- Toxicity control: no
- Other: Positive control

Reference substance:

benzoic acid, sodium salt

Remarks:

Concentration: 3 g/L

Parameter:

% degradation (CO2 evolution)

Value:

35.4

Sampling time:

28 d

Results with reference substance:

Degradation: 92.6% after 9 days, 60% pass level was reached.

Under the test conditions, 34.4% of the test substance was degraded within 28 days. Therefore, the substance is not readily biodegradable.

Table 1: Biodegradation of the reference substance and the test substance under test conditions.

Day	Reference substance	Test substance
	% CO2 total	% CO2 total
0	0.0	0.0
2	13.5	1.8
5	50.2	3.2
9	71.0	9.0
13	79.2	26.4
16	83.3	29.5
21	89.0	34.0
28	92.6	34.4

Validity criteria fulfilled:

not specified

Interpretation of results:

inherently biodegradable, not fulfilling specific criteria

Reference 2

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

Start date: 30 Nov 2011

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions (no GLP, no purity data)

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 1992

GLP compliance:

no

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum: Activated sludge was obtained on 29 Nov 2011 from the sewage treatment plant at Maxéville, France, which treats predominantly domestic sewage (98%).
- Treatment of sludge: On the day of collection, the sludge was washed three times with culture medium (centrifugation for 10 min at 1100 x g followed by resuspension) and sieved through a sieve (100 µm mesh size).

Duration of test (contact time):

28 d

Initial conc.:

26.9 mg/L

Based on:

test mat.

Initial conc.:

20 mg/L

Based on:

other: TOC

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: as stated in the guideline 301 A
- Test temperature: 22 ± 2 °C
- Suspended solids concentration: ≤ 30 mg/L

TEST SYSTEM
- Volume in test flasks: 150 mL
- Number of culture flasks/concentration: 5
- Measuring equipment: indirect measurement of produced carbon dioxide using an automatic respirometer

SAMPLING
- Sampling frequency: continuous measurement (respirometer)

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, 10 replicates
- Toxicity control: not included; respiration inhibition test (OECD 209) with NOEC (3 h) ≥ 1000 mg/L is referenced.
- Positive control: acetic acid, sodium salt, 5 replicates
- Abiotic sterile control: no

Reference substance:

acetic acid, sodium salt

Parameter:

% degradation (CO2 evolution)

Value:

34

Sampling time:

28 d

Details on results:

- The 10-day-window was defined from day 9 to day 19. As the test item attained 9% degradation on day 9 and 24% on day 19, this criterion is not fulfilled.
- The test item attained 34% degradation after 28 days. Hence degradation did not reach the pass level of 60%.

Results with reference substance:

The reference substance attained 81% degradation after 14 days, 60% pass level was reached.

Table 1: Degradation kinetics of the test item

Replicate	Degradation (%) on day
	1	5	10	15	20	25	28
Positive control (mean)	22	60	73	82	86	88	88
Test item 1	0	2	8	11	17	27	34
Test item 2	0	3	9	16	26	38	42
Test item 3	0	3	11	19	24	28	29
Test item 4	0	4	11	19	29	38	41
Test item 5	1	5	13	19	23	25	27
Test item (mean)	0	3	11	19	24	28	34

 

Validity criteria fulfilled:

yes

Interpretation of results:

inherently biodegradable, not fulfilling specific criteria

Description of key information

Not readily biodegradable: 35.4% after 28 d (OECD 301B)

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

Two studies are available investigating the biodegradation of isodecyl pivalate (CAS 60209-82-7). The key study was performed according to OECD 301B (non-GLP) with domestic activated sludge as inoculum and a test substance concentration of approximately 20 mg/L based on TOC. At the end of the study, a mean biodegradation of 35.4% was observed based on CO2 evolution. Therefore, the substance is not readily biodegradable according to the OECD criteria. This is supported by an additional study which was performed under the same conditions as the key study. After 28 d 34% of the test substance was degraded. These results confirmed that the substance is not readily biodegradable according to the OECD criteria.