1-{[1-({1-[(2,2-dimethylpropanoyl)oxy]propan-2-yl}oxy)propan-2-yl]oxy}propan-2-yl 2,2-dimethylpropanoate

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:

14 November - 20 December 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 310 (Ready Biodegradability - CO2 in Sealed Vessels (Headspace Test)

Version / remarks:

2014

GLP compliance:

yes

Remarks:

Statement on compliance with GLP included (15 Jan 2019)

Test material

Test material information

Constituent 1

Reference substance name:

1-{[1-({1-[(2,2-dimethylpropanoyl)oxy]propan-2-yl}oxy)propan-2-yl]oxy}propan-2-yl 2,2-dimethylpropanoate

Molecular formula:

C19H36O6

IUPAC Name:

1-{[1-({1-[(2,2-dimethylpropanoyl)oxy]propan-2-yl}oxy)propan-2-yl]oxy}propan-2-yl 2,2-dimethylpropanoate

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Details on inoculum:

- Source of inoculum/activated sludge: Treatment plant at San Rocco - Monza, Italy. Mixed treatment plant of urban (about 66%) and industrial (about 34%) liquid sewage.
- Storage conditions: aerobic conditions
- Storage length: 2 d
- Preparation of inoculum for exposure: Mud samples before use were analyzed to check the ability to form colony units. Then mud was centrifuged, washed and analyzed to quantify the suspended solids concentration for inoculum preparation.
- Pretreatment: Sampled muds were mixed and let settle.
- Concentration of sludge: 4 mg/L

Duration of test (contact time):

28 d

Initial test substance concentration

Initial conc.:

20.68 mg/L

Based on:

TOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Test temperature: 20 °C
- Suspended solids concentration: 4 mg/L

TEST SYSTEM
- Number of culture flasks/concentration: 20 total replica: 3 replica / check point (days) and 5 replica at 28th day.

SAMPLING
- Sampling frequency: The concentration of inorganic carbon was measured weekly.
- Sampling method: At least 1 h before every determination of inorganic carbon the reaction in one bottle of blank on of reference substance and one for the test item were stopped and 6 mL of 1 M sodium hydroxide was added.

CONTROL AND BLANK SYSTEM
- Inoculum blank: 20 total replica: 3 replica / check point (days) and 5 replica at 28th day (culture medium + inoculum).
- Abiotic sterile control: 8 total replica: 3 replica / check point (days) and 5 replica at 28th day (test item + 50 mg/L HgCl2)
- Toxicity control: 8 total replica: 3 replica / check point (days) and 5 replica at 28th day (43.16 mg test item + reference item per L, based on TOC measurement).
- Reference control: 20 total replica: 3 replica / check point (days) and 5 replica at 28th day.

Reference substance

Reference substance:

other: 1-Octanol

Remarks:

22.04 mg/L (TOC)

Results and discussion

% Degradation

Parameter:

% degradation (inorg. C analysis)

Value:

21

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

99% biodegradation after 28 d.

Any other information on results incl. tables

- The mean amount of TIC present in the blank controls at the end of the test was < 3 mg/L C/L.

- Abiotic degradation was not observed. The TIC was < 10% during the test.

Table 1: % of biodegradation.

Day	% biodegradation
	Reference substance	Test item	Reference substance + test item
0	0	0	0
1	5	1	4
9	96	4	-
17	94	11	-
27	89	16	-
28	99	21	69

Table 2: Validity criteria for OECD 310.

Criterion from the guideline	Outcome	Validity criterion fulfilled
The mean percentage degradation in vessels containing the reference substance is >60% by the 14^thday of incubation	96% on day 9	yes
The mean amount of TIC present in the blank controls at the end of the test is <3 mg C/L	0.716 mg/L C/L	yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

For further information see "any other information on results incl. tables"

Interpretation of results:

not readily biodegradable