Construction

Construction - Overview - EHS - Text

Construction materials using nanotechnology were identified and were evaluated as follows: carbon nanotubes, carbon nanofibres, copper, graphene, graphite nanoparticles, iron oxide, molybdenum, silicon carbide, silicon dioxide crystalline (silica), silicon dioxide, synthetic amorphous (silica), titanium dioxide, tungsten oxide, vanadium pentoxide and zinc oxide.

The basis for the evaluation was “Stoffenmanager Nano” application [1,2] a risk-banding tool developed for employers and employ­ees to prioritise health risks occurring as a result of respiratory exposure to nanoparticles for a broad range of worker scenarios.

The respiratory route is the main route of exposure for many occupational scenarios, while the oral route of exposure is considered minor and sufficiently covered, from a safety point of view, by good hygiene practices established in production facilities as prescribed through general welfare provisions in national health and safety legislation in EU countries [3]. In view of the nature of the products in this sector, oral exposure of consumers is also considered to be minor.

The dermal route may be the main route of exposure for some substances or exposure situations, and cause local effects on the skin or systemic effects after absorption into the body [4]. However, nanoparticles as such are very unlikely to penetrate the skin [5] and consequently nano-specific systemic toxicity via the dermal route is improbable. Therefore, when evaluating risks from nanotechnology for the respiratory route, the most important aspects of occupational and consumer safety are covered.

Roughly four phases can be discerned in the life cycle of construction materials: production, building, use and demolition. If in a phase different degrees of exposure may occur, the highest exposure scenario is taken into account in the risk assessment (worst case scenario).

Within the construction industry, since it does not manufacture the nanomaterials itself, the building phase generates the highest exposure (worst case exposure), the use phase the lowest exposure and the demolition phase intermediate exposure.

Due to the high expected exposure, all nanomaterials reach the highest risk priority during the building phase.

In the use phase, amorphous silicon dioxide, titanium dioxide, spherical SiC and zinc oxide nanoparticles have a low risk priority while carbon nanotubes, molybdenum, nanographite, silicon carbide fibres and whiskers, crystalline silicon dioxide, tungsten oxide and vanadium pentoxide have the highest risk priority and the remainder of the nanomaterials have an intermediate risk priority. It should be noted that in the use phase all nanomaterials are contained in a solid matrix, meaning exposure will be negligible and thus health risks will be low.

In the demolition phase, risk management/evaluation of building materials containing carbon nanotubes, molybdenum, nanographite, silicon carbide fibres and whiskers, crystalline silicon dioxide, tungsten oxide and vanadium pentoxide should receive the highest priority, while amorphous silicon dioxide and zinc oxide have a low risk priority. The building materials containing the remainder of the listed nanomaterials should receive intermediate priority during the demolition phase.

[1] Marquart, H., Heussen, H., Le Feber, M., Noy, D., Tielemans, E., Schinkel, J., West, J., Van Der Schaaf, D., 2008. 'Stoffenmanager', a web-based control banding tool using an exposure process model. Ann. Occup. Hyg. 52, 429-441.

[2] Van Duuren-Stuurman, B., Vink, S., Verbist, K.J.M., Heussen, H.G.A., Brouwer, D., Kroese, D.E.D., Van Niftrik, M.F.J., Tielemans, E., Fransman, W., 2012. Stoffenmanager Nano version 1.0: a web-based tool for risk prioritization of airborne manufactured nano objects. Ann. Occup. Hyg. 56, 525-541.

[3] ECHA, 2012. Chapter R.14: Occupational exposure estimation in: Anonymous Guidance on Information Requirements and Chemical Safety Assessment., Version: 2.1 ed. European Chemicals Agency, Helsinki, Finland.

[4] Ibid

[5] Watkinson, A.C., Bunge, A.L., Hadgraft, J., Lane, M.E., 2013. Nanoparticles do not penetrate human skin - A theoretical perspective. Pharm. Res. 30, 1943-1946

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