Estimates of daily di-isodecyl phthalate (DIDP) intake calculated from urinary biomonitoring data

Biomonitoring of chemical species in biologic media can be a valuable tool in risk assessment since it informs directly on aggregate exposures. While advances in the analytical techniques required for biomonitoring have resulted in increased sensitivity for the detection of chemical species, the detection of a chemical substance in a biological medium (such as blood, urine or breast milk) does not mean that the chemical causes or is associated with an adverse health outcome. In this paper, intake estimates for di-isodecyl phthalate (DIDP), a high molecular weight general purpose plasticizer, were calculated from urinary biomonitoring data representing various population segments and geographic locales. From these data, intake estimates converge on a mean that is <1 μg/kg/day (95th% < 5 μg/kg/day). This intake estimate is at least two orders of magnitude lower than the health-based exposure guidance values (38-150 μg/kg/day) which have been proposed by regulatory authorities and other authoritative bodies as safe exposure levels.