(NHI Nanoblog) The Environmental Protection Agency has published a new “significant new use rule,” or SNUR, for multi-walled carbon nanotubes in today’s Federal Register. The new rule takes effect June 6.
The move requires manufacturers who want to “manufacture, import or process” multi-walled nanotubes in a new way to notify the EPA at least 90 days before doing so. The agency issued a similar edict for both single- and multi-walled nanotubes last fall.
“EPA believes this action is necessary because chemical substance may be hazardous to human health,” the rule says. The rule allows the agency to review the new uses of a substance before approving a company’s planned action.
Nanotechnology leverages super-small particles (a nanometer is a billionth of a meter) to create products with amazing properties. These materials can make bike frames lighter and stronger and sunscreen more transparent on the skin, as well as new medical instruments and medicines that can save lives.
There is broad agreement that nanomaterials hold great promise for a wide variety of applications. But shrinking these substances can change their properties; scientists are struggling to figure out whether, how and why that shift can make them dangerous in the process.
Carbon nanotubes, among the most-studied nano-sized material, are tiny and light. They add strength to products they’re incorporated into, such as steel. Since they can also insulate and conduct electricity, the cylinders hold great promise for a number of other uses. They’re already used in products such as lithium-ion batteries.
Unfortunately, nanotubes also behave like fibers — and, because of their minuscule size, can be inhaled and get stuck in the lungs. That has prompted comparisons to asbestos and has colored the debate over the material.
Since applications that use carbon nanotubes typically encapsulate the material in something solid, the main concern is for workers, who could be exposed to the super-small tubes during the manufacturing process. The National Institute of Occupational Safety and Health issued draft guidelines late last year on how to best protect workers.