A Bioconcentration factor (L/kg) can either be expressed as the ratio of the concentration of a substance in an organism to the concentration in water once a steady state has been achieved (static BCF), or, on a non-equillibrium basis, as the quotient of the uptake and depuration rate constants (dynamic BCF). Static and dynamic BCFs can be equally used for regulatory purposes. The parameter gives an indication of the accumulation potential of a substance.