The weathering of soda-lime-silica float glass. exposed to a polluted, urban environment was conducted in Paris. Both "tin bath" and "air" faces were exposed in two locations: sheltered and unsheltered locations from the rain. Samples were withdrawn after 1, 2, 6, 12 & 24 months and analysed by SIMS, EPMA, FTIR spectroscopy and SEM. Analyses show the formation of leached layers some tens of nanometers thick as a consequence of exposure. For all exposure modes the surfaces were depleted in sodium and, to a lesser extent calcium, and relatively enriched in silica. In general, unsheltered samples are more weathered than their sheltered homologues, and the "air side" appears more weathered than the "tin bath" side. For all the samples the thickness of the leached layer grows over time. Hydration of this layer is clearly detected by SIMS.
