Nanoparticles are used for enhanced oil recovery to affect viscosity, interfacial tension, and wettability of the residual oil and to stabilize foam. While nanotechnology has the potential to provide benefits to oil and gas operations, some of the unique properties of the nanoparticles that make them beneficial raise questions about potential negative impacts on the environment and human health. S. Smita et al. developed a causal diagram to handle the complexity of issues on nanoparticle safety, from their exposure to the effects on the environment and health. The exposure to nanoparticles and their accumulation in microbiota, plants, and humans may result in various adverse effects. In the United States, nanoscale materials are regulated under the Toxic Substances Control Act (TSCA). The Environmental Protection Agency is pursuing a comprehensive regulatory approach under TSCA including an information gathering rule on new and existing nanomaterials and pre-manufacture notifications for new nanomaterials.