Indoor household pesticides: hazardous waste concern or not?

Many indoor household pesticides are efficient and useful tools for a variety of functions necessary to maintain clean, sanitary, and pleasant homes and institutional facilities, and to provide significant public health benefits. They do so by incorporating active ingredients and formulation technology that have not been associated with significant environmental impact in use or when disposed in landfills. Chemical and environmental fate properties, toxicological characteristics, and use patterns of indoor household pesticides that distinguish them from other categories of pesticides which have been associated with environmental contamination should be recognized when HHW policy is debated and established by governmental agencies. Most indoor household pesticides as defined here should not be considered hazardous waste or HHW because those relatively few containers, often no longer full, that have been disposed with MSW over the years have not been associated with environmental contamination. The tiny amounts of those product residues that will reach MSW landfills have been shown, in general, not to have chemical or environmental fate characteristics that would make them susceptible to leaching. Those that do have the potential to leach based on these characteristics, in most cases, do not represent a threat to human health based on toxicological considerations. However, compounds such as propoxur, which are very mobile and relatively persistent in soil and in addition have been associated with significant potential health effects, may be targeted by the screening process as described here and could be selected for further investigation as candidates for special waste management status (such as HHW). Our analysis and recommendations have not been extended to the many types of lawn and garden pesticides that are commonly used by homeowners and are frequently brought to HHW programs. However, their potential for groundwater contamination could also be judged using the same technical considerations as applied in this review to indoor household pesticides. In light of the very high costs of diverting wastes from the MSW stream and into HHW programs, it is recommended that, as a matter of public policy, all categories of household waste that might be considered as HHW be carefully and objectively evaluated for their potential to harm public health or the environment after disposal at MSW landfills.