Workshop Report 24

Challenges in the assessment of natural complex substances

Dan Salvito 1 and Georg Kreutzer2, Karen Jenner 3 1 Research Institute for Fragrance Materials, Inc. (RIFM), USA; 2 Givaudan, Switzerland; 3 Givaudan, Switzerland

Natural Complex Substances (NCS) are materials extracted from plants and used in the preparation of fragrance mixtures for a variety of consumer products. Typically these are classified as UVCBs (Unknown, Variable Composition, or Biologicals), or, minimally, Multi-Component Substances (MCS) for the less chemically complex extracts. Assessment of these materials is required under various regulatory schemes including REACH. While there are methods for considering the ecotoxicity of a mixture using additivity, little has been published on approaches for either environmental fate studies or other assessment methods for NCS. The International Fragrance Association’s Environmental Task Force has provided recommended approaches for NCS biodegradation assessment. Presented here are some recent studies using NCS as examples to assess the ready biodegradability of key constituents of these mixtures in order to provide an overall assessment of the biodegradability of the NCS itself. Particularly challenging was the assessment of sesquiterpene compounds; many of which are not used individually within fragrance preparation and, therefore, data are not readily available for constituent assessment.