Lead Equivalence of various materials

This section presents of useful table of lead equivalence for a number of typical building materials. Use caution when using this data as its from pulsating potential x-ray generators with narrow beams. However, from an educational perspective its quite useful when thinking about the design of hospital diagnostic treatment rooms, by looking at where shielding credit could be claimed from the constructional materials used.

The definition of 'safe' is not strictly an engineering term; it's a societal term. Does it mean absolutely no loss of life? Does it mean absolutely no contamination with radiation? What exactly does 'safe' mean?

– Henry Petroski -