New chemical substances that are not on EPA’s existing Toxic Substances Control Act (TSCA)chemical inventory are subject to premanufacturing notice and approval requirements.  Many NGOs have urged EPA to treat all nanoscale materials as new chemical substances under TSCA because of potential environmental, health, and safety concerns shown in laboratory settings.  Such treatment would trigger TSCA’s premanufacturing notice and approval requirements.  This past July, EPA indicated it did not currently intend to accept this approach because it considers "new" chemicals as those that have molecular identities that are not reflected on the inventory.


On September 7, the National Institute of Occupational Health and Safety (NIOSH) submitted written comments on EPA’s new Nanoscale Materials Stewardship Program in which it urged EPA to change its position and treat all nanoscale materials as new chemical substances under TSCA. In support of its position, NIOSH suggested that "EPA consider particle size . . . in its decision criteria for determining if a nanoscale material is considered a new chemical for the TSCA Inventory. Reducing the particle size to the nanoscale can result in unique or enhanced properties of the nanoscale substance, which can also alter or increase the biological activity and potential toxicity. Thus, the hazard potential of a nanoscale form of a substance may differ substantially (qualitatively and/or quantitatively) from the parent/bulk material that may be listed on the Inventory."
This sets up a possible showdown between EPA and NIOSH on the future treatment of nanomaterials under TSCA. Stay tuned.