Users of TRI data should be aware that TRI data reflect disposal or other releases and other waste management activities of chemicals, not whether (or to what degree) the public has been exposed to those chemicals. Both the toxicity of a chemical and exposure considerations should be taken into account when using the data.

• TRI chemicals vary widely in toxicity or their potential to produce toxic effects. Some high-volume releases of less-toxic chemicals may appear to be a more serious problem than lower volume releases of highly toxic chemicals, when just the opposite may be true.
• The potential for exposure may be greater the longer the chemical remains unchanged in the environment. Sunlight, heat, or microorganisms may or may not decompose the chemical. Smaller releases of a persistent, highly toxic chemical may create a more serious problem than larger releases of a chemical that is rapidly converted to a less-toxic form.

Editor's note: These questions are from EPA documents or BLR subscribers. Do you have a question or comment concerning a particular regulation we could answer in this newsletter? Contact Ana Ellington by phone at 800-727-5257, ext. 2169, fax at 860-510-7224, or e-mail at aellington@blr.com.