from NLM Technical Bulletin:
On December 16, 2019, the National Library of Medicine (NLM) TOXNET (TOXicology Data NETwork) website will be retired. Most content will remain available through other NLM databases as well as from external websites.
TOXNET has served as an integrated system of toxicology and environmental health information. The most frequently used databases are being incorporated into three NLM core resources: PubChem, an open chemistry database; PubMed, a resource for biomedical literature; and Bookshelf, a free online resource to access books and documents in life science and healthcare.
Several resources in TOXNET came from other organizations, such as the U.S. Environmental Protection Agency, and will continue to be available from those sources. Some databases will be retired.
The TOXNET transition page provides a list of its databases and how to access their content. Please check that page and the NLM Technical Bulletin for updates.
If you have questions, please contact NLM Customer Support at https://support.nlm.nih.gov/.