Kad je riječ o tvarima s više sastojaka, UVCB-ovima i smjesama, trebalo bi razmotriti topljivost u vodi svakog relevantnog sastojka radi utvrđivanja odgovarajućih koncentracija pri izlaganju.
EPA, Office of Chemical Safety and Pollution Prevention (2011), Chemical Substances of Unknown or Variable Composition, Complex Reaction Products and Biological Materials: UVCB Substances, http://www.epa.gov/opptintr/newchems/pubs/uvcb.txt.