This paper summarises recent work conducted on the development of exposed core microstructured optical fibres for distributed corrosion sensing. Most recently, exposed-core fibres have been fabricated in silica glass, which is known to be reliable under a range of processing and service environments. We characterise the stability of these new silica fibres when exposed to some typical sensing and storage environments. We show the background loss to be the best achieved to date for exposed-core fibres, while the transmission properties are up to ~2 orders of magnitude better than for the previously reported exposed-core fibres produced in soft glass. This provides a more robust fibre platform for corrosion sensing conditions and opens up new opportunities for distributed optical fibre sensors requiring long-term application in harsh environments.