1-Propanol, 2-methyl-3-[(1,7,7-trimethylbicyclo[2.2.1]hept-2-yl)oxy]-

Biodegradation in water: screening tests

Description of key information

Two studies are available to assess the ready biodegradability of Bornafix. In the key study performed according to OECD guideline 301D (Closed Bottle test) sealed bottles containing the test substance (adsorbed onto glass filter paper) and inorganic nutrient medium were inoculated with activated sewage sludge bacteria and incubated for up to 28 days at 20 ± 1°C. Percentage biodegradation values were determined by comparing the extent of oxygen depletion with the Theoretical Oxygen Demand (5.52 mg O2/L). Additional bottles, containing both the test substance and a readily biodegradable standard substance were prepared in order to provide additional information on the inhibitory effect of the test substance. Bornafix attained only 2 % biodegradation after 28 days and may therefore not be termed as readily biodegradable. Bornafix was not found to be inhibitory to activated sewage sludge bacteria under the conditions of this test.

Key value for chemical safety assessment

Biodegradation in water:

not biodegradable

Additional information

Two studies are available to assess the ready biodegradability of Bornafix. The study performed according to OECD 301D is identified as the key study because this method is considered more suitable compared to OECD 301B for substances that are volatile.

In the supporting study performed according to OECD test method 301B (modified version) a theoretical test concentration of 10 mg C L-1 was used. The inoculum used was secondary effluent obtained from a laboratory rolling tube treatment unit which is fed on 100% settled sewage obtained from Newton Abbot sewage treatment works, which treats sewage of predominantly domestic origin. The bottles were sealed with butyl rubber septa and aluminium crimp caps and placed in an orbital incubator at a nominal test temperature of 20 ± 2°C. They were incubated for 28 days in the dark whilst being shaken at a nominal 150 rpm. Biodegradation was monitored by regular analysis of sacrificial test bottles to determine the amount of inorganic carbon evolved. After 28 days, the test article had undergone 2% biodegradation in the test bottles and therefore cannot be considered readily biodegradable in the test system.