With support from RIFM (Research Institute for Fragrance Materials) since 2012, our team at Stockholm University has been pursuing a research project aimed at assessing the environmental persistence (P) and potential for bioaccumulation (B) of natural complex substances (NCS). The initial vision for the project was to integrate the P and B assessment, thereby avoiding the allocation of resources to assessing one of these characteristics for chemicals which did not satisfy the other, and in that way facilitating the identification of problematic chemicals. Over the past year the work has focused on developing a method to assess B for NCS. The work on B assessment has had two major thrusts. One has been the development of an analytical method for trace analysis in fish that is applicable to the broad spectrum of chemicals that are found in NCS. The second major thrust has been the evaluation of an abbreviated BCF test that relies on benchmarking techniques. We applied this test to the NCS model compound mixture that contained several chemicals with well-characterized BCF values. We showed that there was good agreement between the BCF values measured with our abbreviated method and those that had been measured in more complex experiments with single chemicals.