Sunday, January 14, 2007

The Particle Police

The title of this New York Times piece is almost as cute as the graphic: "Teeny-Weeny Rules for Itty-Bitty Atom Clusters." Last month the City of Berkeley "became the first government body in the United States — and possibly anywhere, according to some analysts — to explicitly regulate businesses that make or use nanoparticles." The city was responding to an environmental impact filing by the Lawrence Berkeley National Laboratory three years ago which declared its intention to build a "molecular foundry." Somewhat ironically, LBNL and the University of California are exempt from the statute.

The most interesting part of the piece for me was a marketing director's argument for why nanoparticles do not (yet) require regulation. Dennis Schneider, with NanoHorizons in State College, Pa., said “You can’t pump them or blow them,” (referring to his company’s products). “You have to bind them to something and drag them around, then change the binding forces to put them somewhere. Or grow them where they are going to be used.” The journalist translates this as meaning that "the nanoparticles now being used are made in such small volume and are so bound up in other material that people are not exposed to quantities worth regulating."

I don't follow the logic here. Claims both for and against nanoparticles assume tiny quantities can have big effects, and particles don't lose their properties when they are "bound" in another material: their properties are often useful (and/or potentially dangerous) only when bound in this way.

Technical insight, anyone?


  1. I recently talked with a materials scientist who works for Michelin. We discussed whether or not Michelin is doing nano...he referred to the longstanding usage of nano-size 'carbon black' as a tire reinforcement and noted that it remains an industry mystery where the particles go as they wear away from tires and are deposited all along the world's highways. Does Berkeley imagine itself regulating auto tires? By their logic, this seems plausible.

  2. Well, the bound/unbound distinction makes *some* sense to me in that if the nanoparticle is part of some stable matrix it's unlikely to get inhaled or absorbed into the bloodstream. After all, no one seems concerned by the nanostructures in their computer, since those are bound to a silicon matrix (the environmental/health issues I've heard about disposal of electronics has to do with chemical properties of heavy metals, rather than their specifically nano properties). On the other hand, a "stable" matrix like a tire can wear down (or get destroyed in a fire or be sawed open by a handyman or whatever). On the third hand, though, we've been releasing nanoparticles that way (e.g. carbon black) for well over a century, so surely the new regulations need some justification that takes that longer history into account.