Definition of "nanomaterial"

The Environmental Protection Agency detailed its plans on Tuesday for research into the possible health and environmental risks of nanomaterials, tiny substances that are finding growing use in products like sunscreens and industrial adhesives.

2009 September 30, Cornelia Dean, “Nanomaterials Under Study by the E.P.A.”, in The New York Times‎

Nanomaterials, substances broken down by technology into molecule-size particles, are starting to enter the food chain through well-known food products and their packaging, but there is little acknowledgment by the companies using them, according to a new report from a nonprofit group that works to enhance corporate accountability.

2013 February 6, Stephanie Strom, “Study Looks at Particles Used in Food”, in The New York Times‎