Oregon State University researchers tested more than 200 nanomaterials as part of a program studying potential risks posed by nanotechnology in pesticides. The study published Oct. 4 in the International Journal of Occupational and Environmental Health determined that most nanomaterials tested did not pose any toxic concerns.
But some nanoparticles did show potential safety problems, leading researchers to determine that pesticide manufacturers will need to disclose exactly what nanoparticles are in their products and ensure the compounds are tested in the same way people would be exposed to them in the real world.
The debate over how safe nano-enabled products are in consumer use and the workplace has created uncertainty for manufacturers utilizing nanotechnology and a potential mess of regulatory requirements. Proposed testing laws could make it costly and difficult for manufacturers to comply, say some industry experts.
One of the ways the Environmental Protection Agency plans to regulate nanotechnology is through the Toxic Substances Control Act. The EPA is developing new Significant New Use Rules under TSCA that would require anyone who intends to manufacture, import or process new nanoscale materials based on chemical substances listed on the TSCA inventory to notify the EPA at least 90 days before they begin such activities.
The notification would need to include risk-related data, such as chemical identification, material characterization, physical properties, commercial uses and toxicity. The EPA also is proposing a rule that would require manufacturers of nanoscale materials to provide the agency with more detailed information, including production volume, methods of manufacture and processing, exposure and release information and available health and safety data.
The EPA plans to submit its proposals regarding nanotechnology testing and reporting before the end of the year.
The EPA's Office of Pesticide Programs is examining potential hazard, exposure, policy, regulatory and international issues that may be associated with pesticides that contain nano-scale materials.
The EPA defines nanoscale materials as "an ingredient that contains particles that have been intentionally produced to have at least one dimension that measures between one and 100 nanometers," according to testimony April 29 by William Jordan, Office of Pesticide Programs' senior adviser.
Main health concerns include skin absorption and inhalation, according of a transcript of Jordan's testimony during the EPA's Pesticide Program Dialogue Committee meeting. Skin absorption can be an issue because nanoparticles are small enough to pass through cell membranes. Inhalation presents another potential safety problem because the particles can move deep into the lung and may translocate to the brain, he says.
Nanosilver is one type of nanoscale material that is receiving particularly close attention from the EPA. Nanosilver has gained widespread use for its antimicrobial properties in various consumer products including socks and washing machines.
In August the EPA proposed a requirement under the Federal Insecticide, Fungicide and Rodenticide Act, or FIFRA, that manufacturers register pesticides containing nanosilver for a four-year period. Under the proposal, manufacturers also would be required to provide information about product chemistry, toxicology, exposure, and environmental data. The EPA would then evaluate the data to confirm the product does not pose a health or environmental threat.
The prospect of having to conduct further testing and re-register a product with the EPA could be quite costly, says John DiLoreto, publisher of the NanoReg Report, an online publication and newsletter that provides information on nanotechnology-related environmental health and safety issues.
"Registration is easily in the multimillion-dollar range," says DiLoreto. "Now the EPA is saying not only does nanosilver require new registration, but any pesticide that has already been registered and found to have a nanoscale material in it is also subject to review and may possibly require a new registration, as well."
DiLoreto says he's not suggesting that some nanoscale materials don't pose a potential risk, but says the agency is presuming a substance to be hazardous just because it's at the nanoscale.
"There needs to be some validation of that rather than just casting a negative light on all nanomaterials because we know that at the nanoscale level many effects of the nanoscale have nothing to do with toxicity," he says.
For instance, certain elements may change color when they're ground down to the nanoscale, but the toxicology of the substance may not be impacted, DiLoreto says.
But some environmental groups say further testing and investigation into potential hazards posed by nanomaterials is necessary to ensure safety. A nonprofit association called the Environmental Working Group sent a letter Sept. 30 to the EPA opposing the agency's proposal to approve a Swiss nanosilver textile coating for sale in the United States.
"Until EPA develops a solid scientific basis for assuring the public that nanosilver presents no danger to people and the environment, EWG argues that the Swiss company should not be granted a permit to market its textile coating," the group contends.
Safety in the Workplace
Questions regarding the safety of nanomaterials also extend to the plant floor. Some of the safety concerns involve the production of carbon nanotubes, says Michael Holman, research director at Lux Research. A number of studies have shown inhaling carbon nanotubes can present health risks, Holman says.
Diversified manufacturer 3M Co. utilizes nanomaterials in various products, including dental restoratives and optical film. The company conducts extensive air sampling to confirm that there are no nanoparticles present in manufacturing areas, says 3M corporate scientist Bill Schultz.
Chemicals manufacturer BASF performs risk assessments at its workplaces to determine potential employee exposure to nanoscale aerosols, says Rudiger Iden, BASF's nanotechnology spokesman. The company also participates in research related to occupational safety, including the development of global standards for testing and assessing exposure in the workplace.
BASF supports the European Union's Registration, Evaluation, Authorization and Restriction of Chemicals, or REACH, legislation as an appropriate means to regulate nanomaterials.
"REACH is a suitable political instrument for documenting nanomaterials because it is for substance regulation and nanomaterials are substances," says Iden. "Political debate in Europe is centering on whether REACH in its current form is sufficient for nanomaterials or whether adjustments are required. The basic science required to answer that question is being developed in the EU Commission's REACH Implementation Projects. BASF is participating in these projects."
The hodgepodge of federal, state and international nanotechnology regulations is one of the biggest challenges manufacturers of nanomaterials face, says DiLoreto. He likens the current regulatory atmosphere to the classic Whack-A-Mole arcade game. Once one regulation is proposed another pops up from different legislative authority, he says.
But there are efforts underway to unite industry groups to establish a common voice for addressing nanotechnology regulatory issues, DiLoreto says. As an example, he referenced a recent meeting involving 16 different organizations that are looking to establish a broader coalition that would address various issues relating to nanotechnology regulation.