Preliminary evaluation of risks related to waste incineration of polymer nanocomposites.

If nanotechnology proves to be successful for bulk applications, large quantities of nanocomposites are likely to end up in municipal solid waste incineration (MSWI) plants. Various studies indicate that nanoobjects might be harmful to human health and the environment. At this moment there is no evidence that all nanoobjects are safely removed from the off-gas when incinerating nanocomposites in MSWI plants. This paper presents a preliminary assessment of the fate of nanoobjects during waste incineration and the ability of MSWI plants to remove them. It appears that nanoobject emission levels will increase if bulk quantities of nanocomposites end up in municipal solid waste. Many primary and secondary nanoobjects arise from the incineration of nanocomposites and removal seems insufficient for objects that are smaller than 100nm. For the nanoobjects studied in this paper, risks occur for aluminum oxide, calcium carbonate, magnesium hydroxide, POSS, silica, titanium oxide, zinc oxide, zirconia, mica, montmorillonite, talc, cobalt, gold, silver, carbon black and fullerenes. Since this conclusion is based on a desktop study without accompanying experiments, further research is required to reveal which nanoobjects will actually be emitted to the environment and to determine their toxicity to human health.