3,5-DICARBOXYPHENYLBORONIC ACID

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Minor deviations; no impact on study reliability

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

5-(dihydroxyboranyl)benzene-1,3-dicarboxylic acid

Cas Number:

881302-73-4

Molecular formula:

C8H7BO6

IUPAC Name:

5-(dihydroxyboranyl)benzene-1,3-dicarboxylic acid

Test material form:

solid

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge (adaptation not specified)

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 4 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

% Degradation

Key result

Parameter:

% degradation (O2 consumption)

Value:

ca. 0

St. dev.:

1.4

Sampling time:

28 d

BOD5 / COD results

Results with reference substance:

Based on a biodegradation rate higher than 60% in 14 days (experimental value: 62.8 % in 10 days) in
the reference control, the test was carried out under good conditions.

Any other information on results incl. tables

In the toxicity control, the biodegradation rate at 14 days was higher than 25%, that highlighted that the test item was not toxic to micro-organisms.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Under the test conditions the substance is not readily biodegradable.

Executive summary:

The objective of this study was to assess the aerobic ready biodegradability of test item 3,5- DICARBOXYPHENYLBORONIC ACID by measurement of oxygen consumption in closed bottles over a 28-day period according to the OECD 301D guideline (July 1992).

The test item, at approximately 4 mg/L, as the sole source of carbon and energy, was incubated in a buffer-mineral salts medium which was inoculated with a mixed population of micro-organisms and kept in completely full, closed bottles in the dark at constant temperature. Degradation is followed by analysis of dissolved oxygen over a 28-d period. The amount of oxygen taken up by the microbial population during biodegradation of the test substance (corrected for uptake by blank inoculum, run in parallel) was expressed as a percentage of ThOD.

As the test item is soluble in test conditions, the test solutions were prepared by dilution of test item stock solution.

 

The study is valid since:

Based on a biodegradation rate higher than 60% in 14 days (experimental value: 62.8 % in 10 days) in the reference control, the test was carried out under good conditions.

The oxygen uptake of the inoculum blank is less than 1.5 mg dissolved oxygen/l after 28 days (experimental value: 1.1 mg/L).

At the end of the test, measurements of oxygen in two replicates of the test item solution did not show a difference of more than 20% (experimental value: 1.4 %).

The residual concentration of oxygen in the test bottles did not fall below 0.5 mg/L at any time.

In the toxicity control, the biodegradation rate at 14 days was higher than 25%, that highlighted that the test item was not toxic to micro-organisms.

 

Results are the following:

Percentage of biodegradation at 28 days: 0 %

Conclusion : Not biodegradable