A special filter for identifying UVCB substances (Substances of Unknown or Variable Composition, Complex Reaction Products and Biological Materials) has been developed and implemented in QSAR Toolbox. The filter analyzes the name of the substance by searching of a key word such as "oil", "wax", "tallow",etc. If a key word is found, then UVCB substance type is assigned to the substance. 

All substances which are recognized as UVCBs have (N/A) as profiling results. These substances are not profiled due to the complex and unknown composition of these substances.