CPWR, The Center for Construction Research and Training, a not-for-profit institution, currently serves as the NIOSH-funded National Construction Research Center via a multi-year cooperative agreement. CPWR recently extended its cooperative agreement with NIOSH that includes a 5-year research project dedicated to the use of nanotechnology in construction. This website is part of our initiative.
Nano-enabled products are emerging in most areas of commerce, including construction. We define nano-enabled products as those to which nanomaterials have been added or the nano-structure has been altered to produce desired effects. They bring clear benefits, but also potential risks. Workers shouldn’t disproportionately bear the risks, as has occurred too often in the past. The first step towards affording workers adequate protection is to ensure they are informed about the use of nanotechnology in construction. That is the goal of this site.
Nano-enabled construction materials are showing up on jobsites.
Construction materials are being significantly improved through the addition of engineered nanomaterials (ENMs) and by changing the nano-structure of materials. Nanotechnology is already being applied to standard building materials such as cement, wood, glass, masonry surfaces, stone, metal, insulation, and epoxies with much more coming. Use of nano titanium dioxide in cement, for instance, can create self-cleaning surfaces that reduce air pollutants, improving air quality and reducing the impact of climate change. Nano-sensors can monitor the structural integrity of buildings, roads, and bridges in real time, possibly preventing catastrophic failures like the Minneapolis Bridge that collapsed into the Mississippi in 2007, killing 13 people.
The risks of nano-enabled construction materials are unclear.
Much is still unknown about the potential for ENMs to cause adverse health effects, but there is cause for concern. ENMs can be more biologically reactive than larger particles composed of the same material weighing the same amount. In some cases ENMs can cross barriers in the body where larger particles cannot. NIOSH has issued Recommended Exposure Limits (RELs) for carbon nanotubes (CNTs) and ultrafine titanium dioxide (TiO2). Nanoscale TiO2 is considered a potential inhalation occupational carcinogen by NIOSH, and CNTs have been linked to asbestos-like lung problems, including mesothelioma, in mice.
Degree of use and exposure to these materials in construction is unclear.
NIOSH has produced excellent guidance on reducing exposures to ENMs. Very little of the guidance developed thus far, however, has been aimed at workers. The NIEHS Worker Education and Training Program has issued the only federal guidance on training workers about the risks of nanomaterials.
There are no requirements in the U.S. for companies to report the inclusion of nanoparticles in product safety data sheets. Unsurprising, NIOSH has reported two-thirds of nano SDSs they collected in 2010-2011 “provided insufficient data for communicating the potential hazards of ENM [Engineered Nanomaterial] documented.” The life cycles of construction products complicate hazard awareness. The most serious exposures may not occur during installation; they may occur years or decades later when the facility is being renovated or demolished. Without labeling requirements, there is no practical way workers would know they may be exposed.
The methods for the CPWR nano inventory
To identify products that appear to be commercially available, we have been monitoring industry news sources and scientific literature; we have also used standard web-based searches, listservs, RSS feeds, and social media. As of September, 2014, there were over 400 items in the inventory. We include an item if any of these conditions are met:
- The word “nano” appears in the company or product name.
- The distributor or manufacturer indicates use of nanotechnology, addition of nanoparticles, or describes the product as a nano-product (e.g. use of the term ‘nano-coating’).
- Use of nanotechnology is ascribed to the product in peer-reviewed scientific literature, trade journals, or other third-party sources publicly available online.
- The Safety Data Sheet references use of nanotechnology.
- The company claims the product is “photocatalytic,” a relatively new property of materials achieved by adding photocatalysts such as titanium dioxide, zinc oxide, or cadmium sulfide. Photocatalytic materials do not by definition contain nanoparticles, but their inclusion greatly increases the desired effect. Consequently, it is likely that nano-sized photocatalysts are being used more frequently due to enhanced performance over larger particles of the same composition.
- Electron microscopy indicates or confirms that ENMs are present or released from a product.
In most cases, we do not have proof of the presence of ENMs in these products; only a reasonable belief the product may be nano-enabled. We provide explanations for why each product is included in the inventory.
The inventory is primarily aimed at construction contractors and workers, as well as health and safety practitioners. It will be regularly updated and new additions will be highlighted. Our database has the following fields:
- Typical Use
- Apparent Use of Nanotechnology
- Reason for Inclusion
- Company Location
- Safety Data Sheet (SDS)
- Related Information
Our inventory will further be used to select candidates for exposure assessment. We have sampled personal exposures while a worker cut and ground several cement-based products and will continue to measure exposures during common construction tasks in both indoor and outdoor environments. We are collaborating with researchers at the University of Loughborough in England who are analyzing construction materials for the presence of nanoparticles and we will link to their findings as they post them.
If you want to cite our work
Please use: eLCOSH Nano, Construction Nanomaterial Inventory (2014). Retrieved [date accessed], from http://www.elcosh.org.