Why is lead used in glass?

Question

Can't high levels lead to lead poisoning? Also, can you give me a link to your source.

Answer 1

http://www.answers.com/topic/lead-glass-...

Answer 2

Lead silicate is a strong glass of high clarity.  In order for it to be toxic, it would have to have a significant (but not necessarily substantial) solubility.  The fact that lead crystal glassware is still in use leads me to believe that its solubility, even in acidic media, is too slight to be of any consequence.

Answer 3

It increase the refractive index so it seems to sparkle like diamonds which also have a high refractive index.

http://en.wikipedia.org/wiki/Lead_crysta...

Answer 4

The lead will stay in the glass unless it is leached out with acid.  Consequently, the  following advice:

Don't store wine, spirits, or vinegar-based salad dressings in lead crystal decanters for long periods of time, as lead can leach out into the liquid.

http://www.nlm.nih.gov/MEDLINEPLUS/ency/...

Lead crystal and food safety

It has been proposed that the historic association of gout with the upper classes in Europe and America was, in part, caused by their extensive use of lead crystal decanters to store fortified wines and whisky.[2] Lin, et al. have statistical evidence linking gout to lead poisoning [3]

Significant amounts of lead can migrate from lead crystal containers into beverages stored in them.[4] Lead crystal typically contains 24–35 percent lead oxide. In a study performed at North Carolina State University, the amount of lead migration was measured for port wine stored in lead crystal decanters. After two days, lead levels were 89 µg/L (micrograms per liter). After four months, lead levels were between 2,000 and 5,000 µg/L. White wine doubled its lead content within an hour of storage and tripled it within four hours. Some brandy stored in lead crystal for over five years had lead levels around 20,000 µg/L.[5][6] To put this into perspective, EPA's lead standard for drinking water is 15 µg/L = 15ppb.[7] Citrus juices and infant formula leach lead from crystal just as effectively as alcoholic beverages. Several companies do make lead crystal baby bottles and it is suspected they may present a health danger to infants.[8]

http://en.wikipedia.org/wiki/Lead_crysta...

Rare earth elements are also used to raise the index of refraction of glass.  They are responsible for the odd colors sometimes seen in high quality camera lenses.