EPA announced March 15, 2010, that its inventory of more than 84,000 selected chemicals manufactured, used, or imported into the US is now available online at no cost. The inventory had been available, but for a fee.
The inventory can be useful in several ways, such as searching for certain basic information about a chemical, confirming that a chemical is in this inventory that is mandated by the Toxic Substances Control Act (TSCA), or sorting the inventory in various ways, such as finding all chemicals that are regulated under a particular rule or statute.
It also provides a better-defined total for all these chemicals, which until recently tended to float between about 60,000 and 100,000, depending on who you asked (including EPA). About 17,000 of the 84,000 chemicals still remain hidden from the public, EPA says, due to claims of business confidentiality, but the agency says it is working to reduce that number.
Internationally, the Commission for Environmental Cooperation (CEC) says there are about 239,000 toxic chemicals that are regulated or in inventories, and that there are about 27 million chemical substances tracked by the Chemical Abstracts Service.
- CEC, "Taking Stock 2005"  (published in 2009); see page 11.
- Chemical Abstracts Service  (fee-based service).
There are several sources for getting more health and environmental information about any chemical that is in the inventory. Many of the information sources are listed at:
- EPA, Existing Chemicals  (see "Finding Public Information on Chemicals").
Each source has its strengths and limitations, and it will help if you take the time to explore these and find ones suited to your beat. Some of the prospects include:
- Agency for Toxic Substances and Disease Registry, Toxic Substances Portal  (limited number of chemicals; information can be dated and not reflective of the full range of scientific evidence; but publications for each chemical such as ToxFAQs, Public Health Statement, or Toxicological Profile are relatively easy to understand).
- eChemPortal  (provides chemical-specific results from up to a dozen or so databases maintained by agencies in numerous countries, offering much more detail than the ATSDR summaries)
- National Library of Medicine, TOXNET  (can provide additional information, such as what products a chemical is in, or locations a chemical is found in the environment).