Two experts from Wake Forest University School of Medicine discussed the good, the bad and the ugly aspects of nanomaterials at the American Society of Safety Engineers (ASSE) Safety 2010 conference in Baltimore.
Celeste Caskey, CSP, and Christopher Kolbash, CIH, AOEE, of the Center for Nanotechnology and Molecular Materials Wake Forest University, told ASSE attendees that nanotechnology would likely be in full swing by 2015 and generate $1 trillion in global commerce.
“The good news about the nanotechnology revolution is that nanomaterial usage is broad in range,” said Caskey.
Indeed, many industries stand to benefit from nanotechnology. Nanomaterials, which measure one-billionth of a meter, can be used in molecular switches, solar cells, textiles, electronics, sunscreen, food/beverages and much more. Biomedical applications include drug carriers, tumor imaging, cell-targeted therapy, wound dressing, cell sensors/microchips and cell and tissue scaffolds, among others.
But the small size and surface area that make nanomaterials so useful also makes them more reactive and possibly more toxic.
Kolbash pointed out that nanomaterials may be able to penetrate cellular membranes. They are respirable, so they can be inhaled deep into the lungs and then possibly pass into the bloodstream. Some researchers also are concerned that nanomaterials could migrate through the skin.
A typical approach to protect workers and the environment from hazardous substances includes using PPE, regulations, engineering controls, toxicological data and administrative controls. The dilemma with nanomaterials, Kolbash said, is the uncertainty surrounding them: Which PPE should researchers use? Will there be specific regulations for nanomaterials in the future? Can fume hoods sufficiently contain nanomaterials? What toxicological data should be used?
“It’s ever-changing,” Kolbash said. “You find new information out all the time.”
The university’s chemical safety committee released a nonmaterial protocol in the fall of 2008, but Kolbash acknowledged that many committee members and environment, health and safety staff lacked the expertise to review the protocol. Wake Forest researchers initiated a literature review and identified faculty with expertise in nanomaterials. They developed a training presentation and created a subcommittee to develop guidelines. The resulting charter set out to “use the best available science to make interim recommendations for workplace safety, health and environmental practices during the use, handling and disposal of nanomaterials.”
Researchers developed a color-coded risk communication system that grouped nanomaterials in the following risk categories:
Level 1 – These nanomaterials have been determined to present little or no hazard
Level 2 – For nanomaterials suspended in liquid or matrix. This requires a base level of PPE and work must be done in a fume hood or biosafety cabinet, not on a bench top.
Level 3 – For dry nanomaterial use or when limited hazard information is known. Researchers must use a hard-ducted biosafety cabinet, double nitrile gloves and, for dry nanomaterials, non-woven lab coats.
Level 4 – Nanomaterials at this level are suspected to present a substantial personal or environmental hazard. PPE would include an N95 or N91 respirator.
“The ugly is really the unknown,” Kolbash said. “There’s a lot of other questions we haven’t gotten to addressing yet.”
Uncertainties at Wake Forest include how to find enough space on campus to work with nanomaterials safely, especially since hard-ducted biosafety cabinets are limited; whether animals can shed nanomaterials; how to properly monitor employee exposure; and how to address a major nanomaterial spill.
“We have tried use prudent practices in the absence of the regulations,” Caskey said. “We will continue modifying the information and protecting our employees as more information comes forward.”