Resinoid of Boswellia serrata (Burseraceae) obtained from exudate by hexane extraction

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

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Resinoid of Boswellia serrata (Burseraceae) obtained from exudate by hexane extraction

EC Number:

948-256-0

IUPAC Name:

Resinoid of Boswellia serrata (Burseraceae) obtained from exudate by hexane extraction

Specific details on test material used for the study:

Name: Resinoid of Boswellia serrata (Burseraceae) obtained from exudate by hexane extraction
EC number: 948-256-0
Batch number: 06/1234
Appearance: Amber crystal
Purity: 100% UVCB
Expiry date: 29 February 2020
Storage conditions: Refrigerated (2-8°C), protected from light and humidity (store in a tightly closed container)
Safety precautions: Routine safety precautions (gloves, goggles, face mask, lab coat) for unknown materials were applied to ensure personnel health and safety.

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic, non-adapted

Details on inoculum:

The inoculum: Secondary effluent, microorganisms from a domestic waste water treatment plant.
Origin: The secondary effluent was supplied from the sewage plant for domestic sewage in Veszprém, Hungary.
Conditioning: The secondary effluent used for this study was allowed to settle approximately for an hour, then the decanted effluent was aerated until use (not later than an hour).

Duration of test (contact time):

ca. 28 d

Initial test substance concentration

Initial conc.:

ca. 1.9 mg/L

Based on:

COD

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

O2 consumption

Details on study design:

--> Preparation of Test Flasks

Sufficient number of BOD flasks was cleaned with 5 - 10 mL of a wash liquid (2.5 g iodine and 12.5 g potassium iodide per litre of 1 % w/v sulphuric acid) by shaking well to coat the bottle walls. After allowing to stand for 15 minutes, the wash liquid was poured off, and the bottles were thoroughly rinsed with tap water and deionised water. Then, the previously described test solutions were filled into the bottles bubble-free until the bottles were completely filled. Then they were tightly closed with glass stoppers.
Test item (flasks 1a and 1b) and procedure control (flasks 4a and 4b) test solutions were agitated on each working day during the experiment.


--> The Test Bottles


The number of test bottles was the follow:
10 bottles containing the test item and inoculum
10 bottles containing the reference item and inoculum (procedure control)
10 bottles containing only inoculum (inoculum control)
10 bottles containing the test item, reference item and inoculum (toxicity control)

The reference item and inoculum (procedure control) were also part of a concurrent study performed in the same experimental period using the same batch of chemicals and solutions. Raw data sheets are clearly associate data with the appropriate study number. Copies of all raw data of positive and negative controls run in parallel were placed in the study file.

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Preliminary study:

The chosen test item concentration was based on the measured chemical oxygen demand (COD): 3.20 ±0.243 mg test item and on the performed 14-d preliminary test. During the preparation of the test solutions they were mixed by mechanical stirring using ultrasonic bath for 10 minutes.

Test performance:

The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item Sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.

% Degradation

Key result

Parameter:

% degradation (DOC removal)

Value:

ca. 19.7

Sampling time:

28 d

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

Under the test conditions the percentage biodegradation of Test Item reached a mean of 19.7 % after 28 days based on the COD of the test item. According to the test guidelines the pass level for ready biodegradability is removal of 60 % ThOD/COD. Therefore, the test item is considered not readily biodegradable.

Executive summary:

The test item (Resinoid of Boswellia serrata (Burseraceae) obtained from exudate by hexane extraction) was investigated for its ready biodegradability in a Closed Bottle Test over a period of 28 days. The biodegradation was followed by the oxygen uptake of the microorganisms during exposure. As a reference item Sodium benzoate was tested simultaneously under the same conditions as the test item, and functioned as a procedure control.

The test system was a microbial inoculum of good quality, collected from a sewage plant for domestic sewage. The sludge was allowed to settle and then aerated until use.

Under the test conditions the percentage biodegradation of Test Item reached a mean of 19.7 % after 28 days based on the COD of the test item. According to the test guidelines the pass level for ready biodegradability is removal of 60 % ThOD/COD. Therefore, the test item is considered not readily biodegradable.

The reference item Sodium benzoate was sufficiently degraded to a mean of 79.2 % after 14 days, and to a mean of 81.7 % after 28 days of incubation, based on ThOD, thus confirming the suitability of the used inoculum.

In the toxicity control containing both, the test item and the reference item Sodium benzoate, a mean of 37.0 % biodegradation was noted within 14 days and 39.2 % biodegradation after 28 days of incubation.

According to the test guidelines the test item can be assumed to be not inhibitory at the applied concentration level of 1.9 mg/L on the secondary effluent microorganisms because degradation was >25 % within 14 days.

The test item was not considered to have significant inhibitory effects on the secondary effluent microorganisms.

Based on the results of this study, the test item is considered not readily biodegradable.