I have been asked to put a protective film onto glass to give it 30 minutes fire protection. The company is Envirograf but never heard of them of any film that is effective in stopping smoke and fire for 30 minutes. Has anybody used it and is it any good ?? Thanks.

Envirograf have been trading since 1983 & are the leading provider of passive fire protection products for the upgrading of legacy walls, floors & doors where rebuilding/replacement is not an option (such as heritage properties).

They (& to my knowledge no one) do not make a fire rated film for glazing as such a product does not exist - there are protective films for decorating/construction to keep glass clean that are fire resistant so as not to spread flame but do not increase the overall fire resistance, similarly there are films to upgrade glass safety for impact safety with similar properties but nothing to upgrade the overall performance that I'm aware of.

Usually with glass that cannot be replaced (e.g. heritage stained glass) it's more common to fix a panel of FR glazing over it using a purpose built frame:

https://envirograf.com/product-category/glazing/

Thank you for your advice and reply.