Nanotechnology: Being proactive
Companies work to protect employees despite unknowns
- Many nanotech companies are taking proactive steps to protect their workers.
- NIOSH has issued recommended occupational exposure limits for two types of nanomaterials: carbon nanotubes and titanium dioxide.
- Studies involving animals have indicated nanoparticles could have adverse health effects.
A few years after it was founded in 2002, nanotechnology company QuantumSphere called upon NIOSH to help protect its workers.
NIOSH visited the Santa Ana, CA-based manufacturer of nanocatalysts four times over three years to review environmental and engineering controls and suggest improvements.
“There’s nothing more important than our workers and our safety,” said Brendan McKenney, QuantumSphere production manager. “We thought it was necessary to do, not just a nice thing to do.”
Nanomaterials are tiny particles – a nanometer is one-billionth of a meter. According to the Centers for Disease Control and Prevention, the materials are used in more than 1,000 consumer products, including cosmetics, clothing and paint. As the industry booms, worker safety in the nanotechnology field is gaining attention.
The National Science Foundation estimates that 6 million people will work in the nanotechnology field by 2020. In addition, workers outside the field may encounter nanomaterials through the handling of products that contain the tiny particles. However, little is known about the materials’ effects on worker health, and no regulatory standards for nanomaterials exist in the United States.
As new nanomaterials are created, some employers are taking measures to protect workers even before they learn how the materials fully affect a person’s health.
QuantumSphere uses personal protective equipment, engineering controls and intensive training. “We’re a small company. We’re not able to do all the testing maybe a larger company might be able to do,” McKenney said. “We have a vision of zero exposure to any of the workers.”
Companies that are proactive in protecting their workers are outnumbering those taking a wait-and-see approach, said Charles Geraci, coordinator of the NIOSH Nanotechnology Research Center. “It’s better to act now than wait to see more information,” Geraci said. “That’s being driven by the reality that there’s something new every day coming out of nanotechnology, so you’ll never have the final answer to everything.
“So, a good approach – and NIOSH’s original premise on this was good – [is that] basic risk management practices can be followed and should be effective for these materials. You just need to have the skill to pick the right ones.”
Nanoparticles behave differently from their larger counterparts. For example, nano-size gold particles are red (instead of yellow) and are reactive, becoming magnetic at about 3 nanometers. These changes can broaden horizons for products. For instance, if certain nanomaterials are added to paint, it can become more sun- or weather-resistant or stick to a surface better.
However, nanomaterials that are inhaled or ingested, or that penetrate skin, may lead to adverse health effects, according to NIOSH.
Bruce Lippy is a Baltimore-based certified industrial hygienist and director of safety research for the Center for Construction Research and Training, also known as CPWR. Lippy pointed out that some nanomaterials are insoluble, so they stay in the body longer. Others may penetrate cell membranes and cause damage, while some kinds of nanoparticle dust could be combustible, NIOSH states. The agency notes that studies have indicated that nanoparticles can move from the respiratory system to other organs.
“They get down deep into the lungs,” Lippy said. “At this size, less than a hundred-billionths of a meter, they do all kinds of strange things.”
Further illustrating why so little is known about nanotech safety is that 7 percent of the National Nanotechnology Initiative’s 2015 budget is earmarked for environmental health and safety, Lippy notes. “There’s not as much money going into it as there should be,” he said. “The other thing is we don’t have any human health data to speak of.”
Several studies have tested nanotechnology’s effects on animals. However, one highly publicized case, published in the American Journal of Industrial Medicine (Vol. 57, No. 5), involved a human. On a lab bench with no protective measures, a 26-year-old chemist handling nickel nanoparticle powder developed throat irritation, nasal congestion, post-nasal drip, facial flushing and skin reactions to her earrings and belt buckle.
Nickel is known to cause sensitization, but was the worker’s reaction instead caused by the size of the particle? The answer is unclear. But companies need to be mindful of when they are working with nanomaterials and how that alters their protective practices, Geraci said.
“What we would have liked is the company to recognize that they were working with the nanoscale form of the material,” Geraci said. “That changes how you think about the material and how you would redo your hazard assessment, and likely would have had that person dispensing that material in an enclosure versus out on an open bench top.”
OSHA, too, notes that exposure limits for a substance may not protect workers from the nano-sized version because some nanoparticles might be more harmful than their larger version.
Shane Journeay, co-author of the study, points out that the chemist handled the nanomaterials in the same manner she might handle larger-size materials: in open air, without ventilation and without other major protective measures.
“It’s reasonable to assume if some types of particles will cause toxicity … it’d be more prudent to wear protective equipment in some of those cases,” Journeay said. “We just don’t know which types of materials those apply to.”
Workers in various industries are end-users of products containing nanomaterials. According to the National Institute of Environmental Health Sciences, those include health care workers (nanosilver used in disinfectants) and cleanup workers (nanoparticles found in hazardous waste). Other potential end-users include firefighters, truck drivers and hotel staff.
Lippy claims that construction workers are a particularly at-risk group. CPWR surveyed 79 union trainers in 2013 and 2014 and found that almost half were unaware nanotechnology had been applied to construction materials. Many small construction firms lack safety and health support, he said, and mobile workers as well as Spanish-speaking workers might not receive proper communication about hazards. In addition, high dust levels can injure the lungs, and construction workers sometimes have flexed, damaged or diseased skin, which could provide entry for particles into the body, Lippy noted.
NIOSH has guidance related to workers dealing with nanomaterials at any time in the material’s life cycle, from production to disposal. OSHA has not issued nano-specific regulations and refers to NIOSH guidance, but said its general industry or construction standards apply to the production and use of nanomaterials. The agency is coordinating with other federal entities to address nanotechnology issues regarding health and the environment.
According to NIOSH, eliminating or substituting nanomaterials for less-hazardous materials is a top control method but may not be an option. For engineering controls, the agency recommends exhaust ventilation, isolation measures, and applying water or other material to suppress dust. Workers should wear gloves, gauntlets and laboratory clothing because nanoparticles can potentially penetrate the skin. Many techniques used to control dry powder processes are effective for protecting against nanomaterials, Geraci added.
An OSHA fact sheet, published in April 2013, states that easily dispersed nanomaterials, or those not contained, pose greater hazards. Employers should provide training and information on results of exposure assessments, PPE, and emergency measures to take in the event of a spill or release.
Meanwhile, NIOSH employs three field teams to provide nanotech guidance to companies.
Geraci said NIOSH advises companies to recognize they are making or using nanomaterials, re-evaluate their processes, check for worker exposures, determine how to eliminate those exposures, and bring in an industrial or safety professional.
“A lot of good questions are being asked out in front of many of these uses and applications,” Geraci said. “We’re not waiting for bad things to happen. Companies, government agencies, academic researchers are all asking the questions up front. That’s helpful for regulatory agencies.”
Lexington, MA-based QD Vision, which bolsters TVs and other displays with light-emitting quantum dots (nanocrystals made of semiconductor materials), received two visits from NIOSH: one in 2006 and another in 2011.
For safety measures, the company manipulates chemicals in a liquid state in fully enclosed containers, company co-founder and chief technology officer Seth Coe-Sullivan said. NIOSH verified the PPE being used and was pleased that the company used sticky mats in front of every entrance and exit of its chemical lab to prevent materials from migrating, he said. Workers also are trained in nano-safety.
Being proactive in protecting workers was an ethical decision. “I was personally hiring chemists young and old. I couldn’t say at the time with absolute certainty it was safe to be working with [nanotechnology],” Coe-Sullivan said. “It had been in university labs for decades and without any effect or repercussion, but we knew there were information gaps, so one of the first ones and easiest ones to address was: ‘Can we keep these workers safe? Can we make sure … the exposures are zero?’”
However, some companies are not as aggressive.
Journeay, a toxicologist and CEO and president of Toronto-based Nanotechnology Toxicology Consulting and Training, said the issue of what companies should do involves two sides.
One side claims that everyone should take protective measures. The other side encourages waiting to see what data emerges because a blanket approach would be costly. Journeay said he has seen “a significant amount of complacency,” as employees do not know they work with nanomaterials or companies feel confident the materials do not pose a hazard. At minimum, companies should examine their materials, identify exposures and determine risks, he said.
“A lot of companies are saying, ‘Let’s take this on a case-by-case basis,’” Journeay said. “But our feeling is whether the particles are toxic or not, companies should be researching this a bit more and trying to identify these issues and seeing where there are areas of risk.”
A broader approach
Although no blanket regulations for nanotechnology and worker safety exist, NIOSH is taking a leading role in conducting research.
The agency has recommended exposure limits for two types of nanomaterials. Based on lab studies, research and observations of industrial practices, NIOSH set the limit at 1 microgram per cubic meter of air for carbon nanotubes and carbon nanofibers. The agency recommends exposure limits of 2.4 milligrams per cubic meter for fine titanium dioxide and 0.3 milligrams per cubic meter for ultrafine titanium dioxide.
NIOSH further noted that rodent studies indicate inhalation of carbon nanotubes or nanofibers might pose a respiratory hazard, and expressed concern about the potential “carcinogenicity” of ultrafine titanium dioxide.
Nanosilver might be the next nanomaterial to receive a recommended exposure limit from NIOSH, Geraci said. The agency has issued a call for information on human exposure and health effects and will possibly conduct a risk assessment.
To help tackle the complexity of new nanomaterials constantly emerging, NIOSH is looking at five or six major classes of nanomaterials, Geraci said.
“What NIOSH is promoting is to take a broader and more general approach at classes of these materials and recognize there will never be enough time, money or people to test every single one of them,” Geraci said. “But if we start understanding the basic characteristics and behavior of groups of them, you’ll be able to manage them responsibly, keep your workers safe and go forward with your business.”