NIOSH has released a new document discussing approaches and strategies to protect workers from harmful exposure during nanomaterial manufacturing, use, and handling processes.
The purpose of the document is to provide the best available current knowledge
of how workers may be exposed and provide guidance on exposure control and evaluation.
According to NIOSH, engineered nanomaterials are “materials that are intentionally produced and have at least one primary dimension less than 100 nanometers (nm).” Nanomaterials have properties different from those of larger particles
of the same material, making them unique and desirable for specific product applications. There are currently more than 1,000 nanomaterial-containing products including makeup, sunscreen, food storage products, appliances, clothing, electronics, computers, sporting goods, and coatings found on the consumer markets today.
It is difficult to estimate how many workers are involved in this field. By one estimate, there are 400,000 workers worldwide in the field of nanotechnology, with an estimated 150,000 of those in the United States. The National Science Foundation in the U.S. has estimated that approximately 6 million workers will be employed in nanotechnology industries worldwide by 2020.
Occupational health risks
associated with manufacturing and using nanomaterials are not yet clearly understood. However initial toxicological data indicate that there is a reason for great concern. Nanomaterials and their potential for harm have been likened to asbestos. As a 2010 report published by the Quebec-based, Institut de recherché Robert-Sauve en santé et en securite du travail (IRSST) noted, “Attention is particularly focused on carbon nanotubes which seem to show, in different animal studies, toxicity similar to that of asbestos
and consequently causing great concern in the international scientific community.” The report found that in general, nanoparticles will normally be more toxic than the same chemical substance of larger dimensions.
What makes nanoparticles particularly concerning is their size and greater surface area which allows them to penetrate deeper into the human body with greater reactivity. Studies have shown that nanoparticles of similar chemical composition have a higher potential toxicity than a micron-sized particle.
Not surprising many, including the European Union’s Agency for Safety and Health at Work reports nanoparticles (NPs) and ultrafine particles are the greatest emerging risk
posed to worker health. They summarize what research has been done into the health effects as follows: “Several studies indicate that, once in the body, NPs can translocate to organs or tissues distant from the portal of entry. Durable, biopersistent NPs may bioaccumulate in the body – in particular in the lungs, the brain and liver. Ultrafine particles have been found to act as an important environmental risk factor
for cardiopulmonary mortality and there is considerable evidence that some NPs are toxic to human health. The basis of toxicity is not fully established, but appears to be primarily expressed through an ability to cause inflammation. NPs could also … [raise] the potential for autoimmune effects. Damage to the cells through oxidative stress, believed to induce many diseases such as cancers is also suggested.”
In response, the IRSST says, “It will be important to develop a precautionary approach
, introduce prevention strategies, foster good work practices and avoid occupational risks so that we may prevent an increase in occupational disease and accidents.”
Environment Canada has also raised the risk to the environment and public health associated with nanomaterials. They believe contamination of the environment by nanomaterials could have significant consequences
in the near future. This contamination can occur when nanomaterials are released into the environment during the manufacturing process. Further contamination may occur when nano-containing products are recycled or otherwise disposed of. Concerns are also growing with respect to exposures through the use the nano-containing products.
However, the greatest exposures to raw nanomaterials are likely to occur in the workplace during production, handling, secondary processing and packaging. NIOSH’s new document recommends that similar to controlling hazards in traditional macro-scale manufacturing, engineering controls should be implemented to reduce exposures to nanomaterials. The identification and adoption of effective control technologies
is an important first step in reducing worker exposure to engineered nanoparticles. Properly designing and evaluating the effectiveness of these controls is a key component in a comprehensive health and safety program.
Want to read the new NIOSH document Current Strategies for Engineering Controls in Nanomaterial Production and Downstream Handling Processes?