Reactions mass of N-{2-[(4-bromo-6-substituted-2-alkyl-1,3-dioxo-2,3-dihydro-1H-isoindol-5-yl)diazenyl]-[alkyl(2-methoxyalkyl)amino]phenyl}acetamide) and N-{2-[(4-bromo-6-substiuted-2-alkyl-1,3-dioxo-2,3-dihydro-1H-isoindol-5-yl)diazenyl]-[alkyl(2-hydroxy-3-phenoxypropyl)amino]phenyl}acetamide

Biodegradation in water: screening tests

Description of key information

The experiment was performed to assess the inherent biodegradability of the test item in an aerobic aqueous media.
An experiment of ready biodegradability was also performed to determine the biodegradation of FAT 41044/A TE.

Key value for chemical safety assessment

Biodegradation in water:

under test conditions no biodegradation observed

Additional information

1) The study was performed to assess the inherent biodegradability of the test item in an aerobic aqueous medium. The method followed was designed to be compatible with CONCAWE (October 1999) “A Test Method to Assess the Inherent Biodegradability of Oil Products” and US EPA Fate, Transport, and Transformation Test Guidelines OCSPP 835.3215 (Paragraph (m)).

 

Methods:

Following the recommendations of the Test Guidelines, the inoculum used in the biodegradation test was pre-exposed to the test item in order to enhance the biodegradative potential of the inoculum.

 

Following the recommendations of the International Standards Organisation (ISO 1995) and the published literature (Handleyet al, 2002), the test item was dissolved in an auxiliary solvent prior to being adsorbed onto a filter paper and subsequent dispersal in test media. Using this method enables small amounts of test item to be accurately added to the test vessels.

 

The test item, at a concentration of 10 mg C/L, was exposed to a mixed inoculum with mineral medium in sealed 125 mL glass Wheaton bottles (total volume when full 160 mL) each containing 107 mL of solution in the dark at 20 ± 1 °C for 56 days.

 

The biodegradation of the test item was assessed by the determination of carbon dioxide produced on Days 0, 7, 14, 21, 28, 35, 42, 49 and 56. Control solutions with inoculum and the reference item, n-hexadecane, together with a toxicity control were used for validation purposes. 

 

 

The test item attained 0% degradation after 56 days based on carbon dioxide production and therefore cannot be considered to be inherently biodegradable under aerobic conditions under the conditions of this test.

2) The ready biodegradability study was performed to assess the ready biodegradability of the test item in an aerobic aqueous media. The method followed was designed to be compatible with the OECD Guidelines for Testing of Chemicals (1992) No. 301F, “Ready Biodegradability; Manometric Respirometry Test” referenced as method C.4-D of Commission Regulation (EC) No. 440/2008 and US EPA Fate, Transport, and Transformation Test Guidelines OCSPP 835.3110 (Paragraph (q)).

 

The test item at a concentration of 100 mg/L was exposed to sewage treatment micro-organisms with mineral medium in sealed culture vessels in diffuse light at approximately 23 ºC for 28 days. 

 

The biodegradation of the test item was assessed by the measurement of daily oxygen consumption values on Days 0 to 28. Control solutions with inoculum and the reference item, aniline, together with a toxicity control were used for validation purposes.

 

The test item attained -10% biodegradation calculated from oxygen consumption values after 28 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F.

 

Statistical analysis carried on the Day 28 Biological Oxygen Demand (BOD) values indicated a statistical difference between the test item and inoculum control vessels, thereby indicating that the test item may be exhibiting an inhibitory effect on the sewage treatment micro-organisms.  

 

The toxicity control containing both the test item and aniline attained 42% degradation after 14 days and 43% degradation after 28 days.

Conclusion

The test item attained -10% biodegradation calculated from oxygen consumption values after 28 days and therefore cannot be considered to be readily biodegradable under the strict terms and conditions of OECD Guideline No. 301F.

 

Statistical analysis carried on the Day 28 Biological Oxygen Demand (BOD) values indicated a statistical difference between the test item and inoculum control vessels, thereby indicating that the test item may be exhibiting an inhibitory effect on the sewage treatment micro-organisms.  

 

The toxicity control containing both the test item and aniline attained 42% degradation after 14 days and 43% degradation after 28 days.

CONCLUSION:

FAT 41044/A TE is not inherently biodegradable and not readily biodegradable.