Chemical Identity Issues EPAs Dilemma

On 23 January 2008, the EPA published a general approach to determining if a particular substance, including nano-substances, is present on the TSCA Inventory [1]. As a general matter, under the TSCA, the EPA regulates substances of a particular molecular identity, traditionally stating that particle size and shape are not factors in this definition. 

With the rapid advancement of nanotechnology and the introduction of nanoscale substances into US commerce, the EPA has had to consider 

The TSCA Inventory, established under Section 8(b) ofthe Act, comprises substances considered to exist in US commerce. A substance not already included on the Inventory is considered to be a new chemical substance pursuant to TSCA Section 3(9). Under TSCA Section 5(a), a person must submit a Premanufacture Notification (PMN) to the EPA at least 90 days before commencing manufacture or import, for a commercial purpose, of a chemical substance not on the Inventory, unless the substance is exempt from reporting. After PMN review and upon receipt of a Notice of Commencement of Manufacture or Import (NOC), the EPA adds the chemical substance to the Inventory, which then becomes an existing chemical substance. Certain nanoscale substances that will be manufactured or imported for commercial purposes are expected to be new chemical substances and therefore subject to the TSCA new chemical reporting requirements, as are any other new chemical substances. 

The EPA does not expect all nanoscale substances to qualify as new chemicals under the TSCA. The EPA intends to determine whether nanoscale substances are new or existing chemical substances based on the case-by-case approach that it has historically applied in determining the Inventory status of chemical substances. 

TSCA Section 3(2)(A) defines the term chemical substance to mean any organic or inorganic substance of a particular molecular identity. .. [3]. Thus, in determining whether a chemical substance is a new chemical for purposes of TSCA Section 5, or instead is an existing chemical, the EPA determines if the chemical substance has 

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