Sandalwood, ext.

Biodegradation in water: screening tests

Link to relevant study record(s)

Reference

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Remarks:

ISO/IEC 17025:2005

Specific details on test material used for the study:

East Indian Sandalwood Oil, Lot APISO-150302SD/SA was used for the study

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, non-adapted

Details on inoculum:

The Inoculum was collected from the Escatawpa, Mississippi POTW on October 18, 2017. This inoculum was immediately taken to the lab, homogenized, then placed into a 6 L Erlenmeyer flask. A Teflon stir bar was then added to the flask. The inoculum was placed on a magnetic stir plate. A CO2-free aeration system, which uses a CO2 scrubber system consisting of NaOH, was connected to the inoculum. The inoculum continued stirring and aerating, uninterrupted, throughout the 1 day conditioning period.

Duration of test (contact time):

28 d

Initial conc.:

521.5 mg/L

Based on:

TOC

Remarks:

stock solution

Initial conc.:

20 mg/L

Based on:

TOC

Remarks:

test solution

Initial conc.:

20 mg/L

Based on:

TOC

Remarks:

positive control

Parameter followed for biodegradation estimation:

TOC removal

Details on study design:

Prior to test setup the appropriate number of 160 mL Hypo-vials were washed and rinsed with tap water. The bottles were then rinsed three times with deionized water (DI H2O) and placed in an oven to dry. They were then removed and placed on the lab bench, labeled, and covered with aluminum foil until use.
The appropriate number of 5 L Pyrex reactor bottles was also washed and rinsed with tap water. The bottles were then rinsed three times with distilled water (DI H2O) and allowed to dry. A bottle was designated as the Blank, Positive Control (PC), and Test Chemical (TC) reactors.
The mineral salt stock solutions for the project were prepared in media bottles using the appropriate chemicals and DI H2O. The chemicals were weighed out using an analytical balance, and the deionized water was measured out using several 1000 mL or 100 mL volumetric flasks. Individual solutions were made up as follows:
Solution 1: The following compounds were added to 1000 mL of DI H2O: 8.50 g of KH2PO4, 21.75 g of K2HPO4, 33.40 g of Na2HPO4 * 2 H2O, and 0.50 g of NH4Cl; The pH of the solution was then adjusted to 7.4.
Solution 2: 36.40 g of CaCl2 * 2 H2O was added to 1000 mL of DI H2O.
Solution 3: 22.50 g of MgSO4 * 7 H2O was added to 1000 mL of DI H2O.
Solution 4: 0.25 g of FeCl3 * 6 H2O was added to 1000 mL of DI H2O:
All mineral salt stock solutions were kept in cold storage at 4 °C chiller until used. A record of all chemical lot numbers and expiration dates are maintained in the laboratory Quality Standards Log.

This particular study commenced on October 19, 2017 and was executed for 28 days.
On the day of project initiation, a 15 liter mineral stock solution was made up according to OECD method 310 specifications. The resulting solution was prepared in a clean 20L carboy as follows:
Aerated DI H2O: 14,805 mL, Solution 1: 150 mL, Solution 2: 15 mL, Solution 3: 15 mL, and Solution 4: 15 mL
A Total Suspended Solids test was performed on the inoculum using a Hach Lange DR5000. The test was performed on a 1:10 dilution of inoculum to DI H20 in triplicate. The average TSS was calculated to be 1,512 mg/L.
The 310 method requires 4 mg of TSS to be added per liter of nutrient solution. Therefore, 10.6 mL of inoculum was added to each designated 5 L reactor bottle already containing the mineral medium.
Total Organic Carbon Analysis
On October 18, 2017, RespirTek, Inc. performed an analysis of the reference and test materials to obtain Total Organic Carbon (TOC) values.
The TOC concentration values obtained during the preparation of the reference and test materials are tabulated below:
Sodium Benzoate (Positive control, PC) 345.5 TOC mg/L
East Indian Sandalwood Oil, (SAN-TC1) 521.5 TOC mg/L
Using the concentrated stock solution TOC values, appropriate test chemical and positive control additions were made to obtain a final reactor TOC value of 20 mg/L for both the PC and TC.
The total amount of product to be added to the nutrient-inoculum solution was added to enough mineral stock solution to obtain a final total reactor composition of 4 L.
- East Indian Sandalwood Oil, Lot APISO-150302SD/SA (SAN-TC1): 153.4 mL SAN-TC1 Stock Solution + 3,500 mL CO2 Free Mineral Stock Solution + 336 mL DI H2O + 10.6 mL of biomass.
- Sodium Benzoate (PC): 231.5 mL PC Stock Solution + 3,500 mL CO2 Free Mineral Stock Solution + 257.9 mL DI H2O + 10.6 mL of biomass.
- Blank (B): 3,500 mL CO2 Free Mineral Stock Solution + 489.4 mL DI H2O + 10.6 mL of biomass.
Each final solution mixture was made up in a 5 L glass bottle for each sample type (Blank, Positive Control (Sodium Benzoate), Test Material(s)). All hypo-vials were separated according its description (Blank, Positive Control (Sodium Benzoate), Test Material(s)). Once the final solution was prepared, it was homogenized with a stir bar and a Cole-Parmer Masterflex Peristaltic Pump was utilized to transfer 100 mL of this solution to each individual vial. The additions to the vials were made by 2 team members, one making the addition, and the other double-checking. As the vials were prepared, they were immediately capped off using aluminum crimp caps and butyl rubber septa.

Reference substance:

benzoic acid, sodium salt

Parameter:

% degradation (TOC removal)

Value:

76

Sampling time:

28 d

Details on results:

The positive control showed 74.3% biodegradation (SD 7.1) whereas the test substance showed 73.1% biodegradation (SD 2.2) (both blank corrected and both measured in triplicates) after 28 days.

Results with reference substance:

The positive control showed 74.3% biodegradation (SD 7.1)

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Sandalwood Oil achieved 76% biodegradation in this OECD 310 study and thus is considered readily biodegradable.

Executive summary:

Sandalwood oil (East Indian Sandalwood Oil sample) was tested for ready biodegradability according to OECD guideline 310 in an ISO / IEC 17025:2005 approved laboratory. Based on the testing conducted in accordance with the specified method above, test product, East Indian Sandalwood Oil, Lot APISO-150302SD/SA, achieved 76% biodegradation. A positive control (sodium benzoate) was run in parallel, showing the test method and microorganism being suitable. The product met the method requirements for a Ready Biodegradability classification.

Description of key information

Sandalwood oil (East Indian Sandalwood Oil sample) was tested for ready biodegradability according to OECD guideline 310. The test product, East Indian Sandalwood Oil, Lot APISO-150302SD/SA, achieved 76% biodegradation. A positive control (sodium benzoate) was run in parallel, showing the test method and microorganisms being suitable. Thus, the test material Sandalwood oil is considered being readily biodegradable.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater