Is ice tea safe to drink in large amount?

Iced tea: Iced tea is generally safe -- how "large" of an amount are you talking about? If not loaded with sugar or other additives, it should be fine. For instance, "long island" iced tea (containing alcohol) would be another issue.

Depends: Be aware of sugar content in it, may be too much on a daily basis.

How much is large: Amt ? Verdose of green tea (usually extract) may lead to irritability, insomnia, irregular or rapid heart rate, muscle twitching, nausea, vomiting, diarrhea, abdominal cramps, liver damage, trouble breathing, dizziness, fever, confusion, hallucinations, diuresis, seizures, loss of consciousness ; even death.