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Novel or Newly Discovered Hazards
Safe Pesticides &
Safe Products
Despite the rigorous testing requirements that are part of the registration process for manufactured chemicals and pesticides, unanticipated issues periodically emerge that require EPA to revisit the risk potentials of certain compounds. To meet this challenge, a focus of EPA research is on new or novel hazards that require additional research be conducted in a timely fashion.
Two classes of chemicals currently under investigation because of the unique problems they pose are (1) perfluoroalkyl acids and (2) high potency herbicides. Perfluoroalkyl acids, or PFAAs, are unique among chemicals in the biological responses they elicit. High potency herbicides pose a danger because it is difficult to detect the presence of these chemicals in the soil or plant tissues that may be affected.
Perfluoralkyl Acids
PFAAs are of great concern for the following reasons: their global distribution, persistence in the environment, accumulation in humans and wildlife, proven toxicity in tests on animals, and a paucity of information about their mechanism of toxicity and of potential replacements.
EPA scientists are working to determine the mechanism by which PFAAs induce their toxic effects. Specific attention is focused on the developmental, immunological, reproductive, hormonal, and carcinogenic effects of this class of chemicals. The hope is that research on specific PFAAs will provide information that will be useful in predicting the effects of similar compounds, such as those that may be developed as replacements for the current PFAAs, and that will assist scientists in making predictions about human health effects based on the effects observed in tests on animals.
High Potency Herbicides
New low-dose, high-potency herbicides, i.e., herbicides with a maximum application rate of 0.5 pounds of active ingredient per acre, are of special concern in terms of potential effects beyond on the targeted plants because their low application rate makes it difficult to detect their presence in soil or plant tissues that may be affected. Thus there is a need to understand the effects these pesticides can have on individual plant species, agricultural ecosystems, and on native plant ecosystems.
Research is underway to develop databases and risk-assessment tools and models, tests for evaluating the adverse effects of herbicides at critical stages in a plant's life, and molecular markers or tests to characterize risks to a wide array of species.
