Under United States law, pesticide misuse is considered to be the use of a pesticide in a way that violates laws regulating their use or endangers humans or the environment; many of these regulations are laid out in the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). The most common instances of pesticide misuse are applications inconsistent with the labeling, which can include the use of a material in any way not described on the label, changing dosage rates, or violating specific safety instructions. Pesticide labels have been criticized as a poor risk communication vehicle, leading some officials and researchers to question whether "misuse" is an appropriate term for what are often "unintended uses" resulting from a poor understanding of safety and application instructions.