to the sludge/solids compartment of the sewerage system which is expected to be incinerated, disposed of to landfill or spread onto agricultural land. The notable exception is the soluble component present at less than 5% which is likely to remain in solution where it will undergo biodegradation. . Fate Stepan TabTM-2 is a reaction mixture containing products of low water solubility (with the exception of one minor component) and therefore leaching from landfill sites or agricultural land is not expected. Incineration of the notified substance will produce oxides of carbon. Upon release to the environment in sewage effluent, the notified substance would be expected to disperse and partition to sediment. The biodegradation potential of the notified substance was assessed using a "closed bottle test" with activated sludge bacteria. Testing was over a 28 d period, with the samples incubated in the dark at a temperature of 20 1°C. Analysis for degradation (by oxygen consumption) is indirect and therefore the insolubility of the notified substance in water does not interfere with the analysis. The notified substance was to degrade 57.1% after 28 d in a mg.L-1 solution, indicating that it is not readily biodegradable. According to the OECD guidelines (No 301D) for the "closed bottle test" the cut-off figure to be considered readily biodegradable is 60%. This result probably reflects the ready biodegradability for some components but not others. Although no bioaccumulation data was presented, the high fat solubility of the notified substance would suggest that the notified substance has a potential to bioaccumulate. However, the low water solubility of the bulk of the notified substance negate this initial indicator since without an effective transport mechanism bioaccumulation is unlikely.
to the sludge/solids compartment of the sewerage system which is expected to be incinerated, disposed of to landfill or spread onto agricultural land. The notable exception is the soluble component present at less than 5% which is likely to remain in solution where it will undergo biodegradation. . Fate Stepan TabTM-2 is a reaction mixture containing products of low water solubility (with the exception of one minor component) and therefore leaching from landfill sites or agricultural land is not expected. Incineration of the notified substance will produce oxides of carbon. Upon release to the environment in sewage effluent, the notified substance would be expected to disperse and partition to sediment. The biodegradation potential of the notified substance was assessed using a "closed bottle test" with activated sludge bacteria. Testing was over a 28 d period, with the samples incubated in the dark at a temperature of 20 1°C. Analysis for degradation (by oxygen consumption) is indirect and therefore the insolubility of the notified substance in water does not interfere with the analysis. The notified substance was to degrade 57.1% after 28 d in a mg.L-1 solution, indicating that it is not readily biodegradable. According to the OECD guidelines (No 301D) for the "closed bottle test" the cut-off figure to be considered readily biodegradable is 60%. This result probably reflects the ready biodegradability for some components but not others. Although no bioaccumulation data was presented, the high fat solubility of the notified substance would suggest that the notified substance has a potential to bioaccumulate. However, the low water solubility of the bulk of the notified substance negate this initial indicator since without an effective transport mechanism bioaccumulation is unlikely.
NA117FR.docx