By law, EPA is responsible for regulating the pesticides that are used by growers to protect crops and for setting limits on the amount of pesticides that may remain in or on foods marketed in the USA. These limits on pesticides left on foods are called "tolerances" in the U.S. (they are referred to as maximum residue limits, or MRLs, in many other countries).
EPA establishes tolerances for each pesticide based on the potential risks to human health posed by that pesticide. Some risk assessments are based on the assumption that residues will always be present in food at the maximum level permitted by the tolerance. Other risk assessments use actual or anticipated residue data, to reflect real-world consumer exposure as closely as possible.
As stated above, EPA sets the tolerance limits for each pesticide that may be found on foods. But the US Department of Agriculture (USDA) enforces tolerances established for meat, poultry and some egg products, while the Food and Drug Administration (FDA) enforces tolerances established for other foods. In this way, these federal agencies ensure that the nation's food supply is maintained safely at all times.
PubChem, released in 2004, provides information on the biological activities of small molecules. It is a component of NIH's Molecular Libraries Roadmap Initiative.
PubChem is organized as three linked databases within the NCBI's Entrez information retrieval system. These are PubChem Substance, PubChem Compound, and PubChem BioAssay. PubChem also provides a fast chemical structure similarity search tool. More information about using each component database may be found using the links in the homepage.
Links from PubChem's chemical structure records to other Entrez databases provide information on biological properties. These include links to PubMed scientific literature and NCBI's protein 3D structure resource. Links to PubChem's bioassay database present the results of biological screening. Links to depositor web sites provide further information. A PubChem FTP site, Download Facility, Power User Gateway(PUG), Standardization Service, Score Matrix Service, Structure Clustering, and Deposition Gateway are also available.
PubChem provides tips and example code to allow users to add PubChem search tool (free) in their sites. A PubChem publication site provides links to published articles.
Substance Registry Services (SRS) is the Environmental Protection Agency's (EPA) central system for information about substances that are tracked or regulated by EPA or other sources. It is the authoritative resource for basic information about chemicals, biological organisms, and other substances of interest to EPA and its state and tribal partners.
The SRS makes it possible to identify which EPA data systems, environmental statutes, or other sources have information about a substance and which synonym is used by that system or statute. It becomes possible therefore to map substance data across EPA programs regardless of synonym.
The system provides a common basis for identification of, and information about: