Managing emissions of active pharmaceutical ingredients from manufacturing facilities: an environmental quality standard approach.

Active pharmaceutical ingredient (API) residues have been found to be widespread in the aquatic environment, albeit in most cases at trace levels, with the route to the environment predominantly being via therapeutic use and subsequent excretion to sewer. Although manufacturing discharges may be a low overall contributor to environmental concentrations, they need to be managed effectively so that they do not adversely affect the local receiving environment. In order to achieve this, a risk-based approach is proposed that identifies the long-term and short-term concentrations, referred to as environmental reference concentrations (ERCs) and maximum tolerable concentrations (MTCs), respectively, of an API which should not be exceeded in the aquatic environment receiving effluent from pharmaceutical manufacturing sites. The ERC approach is based on established environmental quality standard concepts currently used in much national and international legislation. Building on these concepts, the approach takes into account indirect exposure of potential consumers such as fish-eating mammals and humans, as well as primary producers (e.g., algae) and primary and secondary consumers (e.g., invertebrates and fish). Although chronic toxicity data are preferred for ERC derivation, acute data, with appropriate considerations of uncertainty, may be used when chronic data are not available. This approach takes all available information into account, particularly for older established medicines that may predate current regulatory requirements for environmental data, and consequently helps prioritize resources for environmental testing. The ERC approach has been applied to 30 of AstraZeneca's APIs. Merits of the approach are discussed together with opportunities for potential future refinement.