The Toxic Substances Control Act (TSCA) was passed October 11, 1976, and it has been amended several times since then. Currently (August, 2010), there is draft legislation that is being discussed in Congress that would significantly reform TSCA with the intent to make it less unwieldy, i.e., easier to apply to chemicals in commerce (Toxic Chemicals Safety Act of 2010; HR 5820). Chemicals that are specifically subject to other statutes, such as the Federal Insecticide, Fungicide, & Rodenticide Act (FIFRA) and the Food, Drug, & Cosmetics Act (FD&CA), are exempt from TSCA.

We provide risk assessment support to clients with chemicals subject to TSCA. The part of TSCA that has been very actively implemented and is therefore most relevant to our support in this area has been section 5, Premanufacture Notification (PMN) and related Significant New Use Rule (SNUR) actions. Among the draft bills being considered during the current TSCA reform are several provisions that would increase the overall focus on risk assessment, especially under section 5, and one draft even proposes that the EPA determine that chemicals pose a "reasonable certainty of no harm" for all intended uses, which is the standard required under the more vigorous FIFRA/FQPA (Food Quality Protection Act) program. (This standard may be problematic to implement.) Thus we anticipate a broader need for environmental fate and risk assessment support after the next round of TSCA amendments. (TSCA reform proposals are being tracked and analyzed in more detail by the ACTA Group.)

There has also been a greater focus in recent years on regulation of "persistent, bioaccumulative, and toxic" (PBT) compounds, and on the need to establish a scientific assessment and regulatory framework for nanoparticles.

PBT Chemicals. "Bright line" (cutoff) criteria have been established: as part of the U.S. EPA's TSCA programs for new chemicals (section 5) and within the TSCA PBT profiler; under the Canada Environmental Protection Act; within the United Nations Environmental Program (UNEP; Stockholm Convention); and as part of the European Union's overall chemical regulation program, REACH. Increasingly, scientists realize that bright line/cutoff PBT criteria should be replaced by a more integrated approach that better predicts persistent environmental risks. However, until this happens, chemical substances often face the possibility of severe regulation if any or all of the cutoff values are exceeded.

Nanomaterials. Nonmaterials or nanoparticles are often defined as substances that have a size of approximately 1 to 100 nanometers (10-9 meter, 0.00000004 inch) in any dimension. Practically, they are bigger than a typical molecule but smaller than a typical solid. Examples are carbon nanotubes, fullerenes, nano silver (AgNP), nano titanium dioxide, nano zinc oxide, and combustion soot.

Regulation of nanomaterials is in its infancy, and the science in this area is also rapidly evolving (e.g., U.S. EPA 2008, Nanomaterial Research Strategy, EPA/600/S-08/00; Handy, von der Kammer et al., 2008, The Ecotoxicology and Chemistry of Manufactured Nanoparticles, Ecotoxicology 17:287-314).

Examples of nascent regulatory activities in this area:

• EPA/FIFRA evaluation of silver nanoparticles;
• EPA/TSCA information requirements under section 8(a), as well as Significant New Use Notice requirements; and
• Consumer Product Safety Commission review under the Federal Hazardous Products Act.