Hazards

The Nanotechnology Industries Association (NIA) maintains a Regulatory Monitoring Database of nanotechnology related topics. Regulations and standards are gathered from around the world.

Furthermore, the  National Institute for Occupational Safety and Health (NIOSH) has recently published recommendations on safety when working with nanomaterials, named “Current Strategies for Engineering Controls in Nanomaterial Production and Downstream Handling Processes”. The IOSH in the UK has also granted funds for nanotech health of market and potential market materials. The Institute of Demolition Engineers and the National Federation of Demolition Contractors is further involved to determine potential methods for demolition and recycling of such products.

||Cell damage

Substantial damage from commercially available Ag and ZnO NPs is found. These NPs produce free radicals (i.e. reactive oxygen species or ROS). In turn, cells can experience cancerous mutations or even death. The threshold concentration is currently found to be 10 micrograms per milliliter. Ag is further found to be significantly toxic when penetrating cells. These findings are in contradiction to the benefits of traditionally using Ag colloid potions for their antiseptic properties. Along the same lines, traditionally beneficial Au used for drug delivery can disrupt the production of progesterone and affect a woman’s fertility.

SiO2 NPs are found to be toxic and have significant adverse effects on macrophages (failure to take up lipids) This leads to atherosclerotic lesion development and its consequent cardiovascular events, such as heart attack or stroke.

Astrocytes help regulate the exchange of signal-carrying neurotransmitters in the brain and supplying their energy. TiO2 NPs are found to cause abo 67% mortality of these cells at 100 ppm.

||Personal protection

Gloves of different thicknesses made of nitrile, latex, neoprene and butyl were exposed to the passage of commercial TiO2 NPs. With the exception of butyl, a higher risk of penetration was seen with colloidal NPs, especially when subject to biaxial dynamic deformation.

||Product end-of-life cycle

Thermal, biological, or mechanical-biological waste treatment plants are not entirely familiar on how waste containing nanomaterials would behave in their facilities. These facilities need to handle all nano waste cycles, including by-products, contamination, and end-of-life. With incineration processes, it is so far believed that CNTs degrade almost completely. Graphene is also suseptible to hydroxyl radicals as a part of an oxidation process (such as TiO2-UV). However, most inorganic oxides are still present in the form of bottom ash, slag, or filter residue. Understanding of nano exposure limits is still being developed and any handling with these products should be exercised with caution. In summary:

  • when incinerated, nanomaterials can be destroyed, remain unchanged, or converted into oxides, chlorides or other
  • nanomaterials >100 nm are efficiently filtered
  • nanomaterials <100 nm are partially retained by filters, possibly up to 80%
Advertisements