<i>"... The liquid glass spray produces a water-resistant coating only around 100 nanometers (15-30 molecules) thick. On this nanoscale the glass is highly flexible and breathable. The coating is environmentally harmless and non-toxic, and easy to clean using only water or a simple wipe with a damp cloth. It repels bacteria, water and dirt, and resists heat, UV light and even acids. ... Liquid glass spray is perhaps the most important nanotechnology product to emerge to date. It will be available in DIY stores in Britain soon ..."</i><p>Not news but a PR release. It pays to be cautious when making claims to be <i>"new"</i>, <i>"harmless"</i> and <i>"available in stores soon"</i>. The claim the particles are 100 nanometers is significant.<p>Why?<p>Well it appears that a lot of research is done on nanometer particles, health and lung function and the threshold for damage around 100 nanometers ~ <a href="http://www.google.com/search?q=100+nanometer+particles+and+lung+function" rel="nofollow">http://www.google.com/search?q=100+nanometer+particles+and+l...</a> even more for 50nm. Below a certain size, particles are membrane permeable - when breathed in, pass directly through the air/blood membranes of the lung into the bloodstream. There is a lot of research to suggest that sub .25µm particles of diesel (2.5 micrometers = 2500 nanometers) causes health problems ~ <a href="http://www.google.com/search?q=.25+micron+diesel+particles+health" rel="nofollow">http://www.google.com/search?q=.25+micron+diesel+particles+h...</a>  An explanation here to why ~ <a href="http://www.lungoregon.org/air/Diesel.html" rel="nofollow">http://www.lungoregon.org/air/Diesel.html</a><p><i>"... PM (Particulate Matter) has now been linked to a broad range of adverse health effects, both respiratory and cardiovascular, in epidemiologic and toxicologic research.  ... The primary impetus for the 1997 PM NAAQS and the current proposed revision has been epidemiologic evidence that associates PM with increased risk for mortality ..."</i> ~ <i>"Small Particles with Big Effects"</i>, William N. Rom, M.D., M.P.H.", <a href="http://ajrccm.atsjournals.org/cgi/content/full/173/4/365#BIB2" rel="nofollow">http://ajrccm.atsjournals.org/cgi/content/full/173/4/365#BIB...</a><p>So I'd really like to know when materials like this are even suggested before they are released for commercial and human use without significant long term testing. Think asbestos and the long lead time for <a href="http://en.wikipedia.org/wiki/Asbestosis" rel="nofollow">http://en.wikipedia.org/wiki/Asbestosis</a>