1950’s Fire King Milk Glass Dishware - Is it Lead Free?

I've always liked milkglass, and saw some on Etsy from the 1950's (I think, given the stamp and what google says about the date stamp). 

From all what I can learn through google, there was arscenic in milk glass back in the 1800's, and then they stopped that and used lead for awhile instead to acheive the same milky look, up to the early 1900's.