[Biologic degradation of phenoxypropanolene. Biodegradability of phenoxypropanols]

Phenoxypropanols have been used for some time as ingredients in surface and instrument disinfectants. Since the residual solutions of these preparations are discharged into the waste-water, the biodegradability of the ingredients used is of great importance. Tests by means of the Zahn-Wellens test in accordance with OECD guidelines have shown that phenoxypropanols are biodegradable. In further studies it was investigated whether unwanted intermediate products are formed in considerable amounts. Of particular interest was the question of the possible development of phenol outside the bacterial cells. To test the biodegradability of the aromatic alcohols and to ascertain whether there is extracellular formation of phenol, microorganisms were isolated from the municipal sewage plant at Stellinger Moor, Hamburg, and from water from the River Elbe. Phenoxypropanol-containing solutions were then inoculated with the bacteria and incubated at 30 degrees C. At regular intervals both the concentration of the alcohols was determined and the test for phenol was performed by means of liquid chromatography on reverse phase material (RP 18) and detection with a photodiode array detector. The breakdown of the phenoxypropanols was monitored for a period of up to 4 weeks. During this period a clear breakdown of the aromatic alcohols was observed. No phenol was detected.