Allyl (3-methylbutoxy)acetate

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

(Modified Sturm Test)”, adopted on 17 July 1992.

GLP compliance:

yes (incl. QA statement)

Oxygen conditions:

aerobic

Inoculum or test system:

sewage, domestic, adapted

Details on inoculum:

The inoculum was secondary effluent, collected from a treatment plant receiving predominantly domestic sewage. This effluent was used as test system as it is recommended in the guideline. A fresh sample of secondary effluent was collected from the treatment plant and was kept aerobic during transport.

This effluent was allowed to settle for one hour, decanted and the decanted effluent was used in the test.

Source of the Inoculum

Sewage Treatment Plant
Eurofins Advinus Limited
Bengaluru – 560 058
India

Determination of Bacterial Population in the Inoculum

The bacterial population in the inoculum was determined as colony forming units (CFU/mL) by diluting the inoculum to an appropriate dilution and then plating on nutrient agar plates.

Preconditioning of the Inoculum

The decanted effluent was preconditioned by aerating for 5 days at 22 to 24C.

Duration of test (contact time):

ca. 28 d

Initial conc.:

ca. 240 mg/L

Based on:

test mat.

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

Preparation of Test Flasks

Flask No. Contents
1 & 2 Test suspension – test item and inoculum
3 & 4 Inoculum blank – only inoculum
5 Procedure control – reference item and inoculum
6 Toxicity control – test item, reference item and inoculum

To each 5 L flask, 2400 mL of mineral medium was added and mixed with 300 mL of the pre-conditioned inoculum. A separate 3000 mL of mineral medium was also prepared in a flask to use it for further dilutions.

A sample of the mineral medium was checked for the inorganic carbon content.

These flasks were aerated with CO2 free air at 43 to 50 mL/minute, overnight to purge the system of carbon dioxide.

Key result

Parameter:

% degradation (CO2 evolution)

Value:

>= 75.18 - <= 81.05

St. dev.:

4.15

Sampling time:

13 d

Parameter:

% degradation (CO2 evolution)

Value:

>= 52.33 - <= 58.46

Sampling time:

10 d

Details on results:

8.3 Production of Carbon-dioxide during the Treatment Period
The carbon dioxide production during the treatment period is given in Table 1. pH of the test solutions at the end of the test is given in Table 2.

The mean carbon dioxide produced from the inoculum blank (Flask No. 3 and 4) on Days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the treatment was 20.63, 16.61, 11.88, 26.68, 14.80, 11.77, 10.89, 10.01 and 7.81 mg, respectively. The total carbon dioxide produced from the inoculum blank for throughout the test period was 43.69 mg/L.

The cumulative carbon dioxide produced from the test item was 15.56, 40.64, 71.77, 99.76, 138.31, 178.79, 214.65, 248.97 and 281.31 mg in Flask 1 on Days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the treatment, respectively. Similarly, in Flask 2 it was 12.81, 31.62, 61.43, 89.31, 128.30, 168.34, 204.09, 238.19 and 271.41 mg on Days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the treatment, respectively.

The cumulative carbon dioxide produced from the reference item (Flask No. 5) was 29.97, 65.61, 103.78, 100.31, 125.55, 141.83, 159.76, 183.41 and 199.69 mg, on Days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the treatment, respectively.

The cumulative carbon dioxide produced from the toxicity control (Flask No. 6) was 21.17, 50.98, 82.55, 71.16, 93.87, 114.66, 128.08, 144.03 and 157.78 mg, on Days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the treatment, respectively.

The pH of the test solutions at the end of the test was 7.81, 7.82, 7.81, 7.82, 7.81 and 7.82 in Flask 1, 2, 3, 4, 5 and 6 respectively.

8.4 Percent Degradation
The percent degradation of the test item, reference item and toxicity control is presented in Table 3 and Figure 1.

The percent degradation of test item was 164.84% and 159.04% in the Flask No. 1 and 2, respectively at the end of the test. The mean per cent degradation of test item was 161.94% at the end of test while, the percent degradation of reference item was 119.32% and the toxicity control was 93.66% at the end of the test. It was observed that the mean degradation of test item reached 78.12% on Day 13 after reaching 21.17% on Day 6. The degradation of test item, Allyl Amyl Glycolate reached more than 60% pass level in 10-day window period after reaching 10% of ThCO2 production and within the 28-d period of the test.

Based on the results, the test item was concluded as readily biodegradable as 78.12% mean degradation was achieved in between Days 6 and 13, crossing 60% pass level in 10-day window period after reaching 10% of ThCO2 production and within the 28-d period of the test.

Validity criteria fulfilled:

yes

Interpretation of results:

readily biodegradable

Conclusions:

Based on the results, the test item was concluded as readily biodegradable as 78.12% mean degradation was achieved between Days 6 and 13, crossing 60% pass level in 10-day window period after reaching 10% of ThCO2production and within the 28-d period of the test.

Executive summary:

The ready biodegradability of Allyl Amyl Glycolate was tested using the CO2 Evolution Test. The test item was added to two test vessels at the concentration of 24 mg/L (equivalent to 15.5 mg of Total Organic Carbon/L).  Two control treatments containing only the inoculum, one reference item treatment and one toxicity control treatment containing the test item and the reference item were also tested. All the treatments were added with equal volume of inoculum which was collected from the secondary effluent treatment plant receiving predominantly domestic sewage.

Treatment mixtures were aerated for 29 days with carbon dioxide (CO2) free air. The CO2 released was trapped in a series of bottles containing barium hydroxide, which were connected to the outlet of each test vessel. The residual barium hydroxide was measured on Days 3, 6, 8, 10, 13, 16, 20, 24, 27 and 29 after the initiation of the test.

The mean per cent degradation of test item was 161.94% at the end of test while, the percent degradation of reference item was 119.32% and the toxicity control was 93.66% at the end of the test. It was observed that the mean degradation of test item reached 78.12% on Day 13 after reaching 21.17% on Day 6. The degradation of test item, Allyl Amyl Glycolate reached more than 60% pass level in 10-day window period after reaching 10% of ThCO2 production and within the 28-d period of the test.  

The test fulfilled all the validity criteria.

Based on the results, the test item was concluded as readily biodegradable as 78.12% mean degradation was achieved between Days 6 and 13, crossing 60% pass level in 10-day window period after reaching 10% of ThCO2 production and within the 28-d period of the test.

Key value for chemical safety assessment

Biodegradation in water:

readily biodegradable

Type of water:

freshwater