Are Leadlights Safe?
Yes, in normal glazing situations, it is very safe.
Leadlight behaves differently to normal panes of glass, as it absorbs vibrations and movement more readily, therefore it doesn’t shatter as easily. During the Second World War, most of the leadlights in the churches around London survived the bombing raids while every normal window near by were blown out!
There are safety standards for the use and glazing of normal glass and leadlights in areas of the home where human impact may be a concern, eg: in bathrooms or glass panes that go down to the floor and these are always followed and discussed where applicable.
Like all glass, it is susceptible to heavy blows and ball damage, break–in’s etc have to be taken into account when considering leadlights.