Steel Bottle vs Copper vs Plastic
Good bottles made of 304 food grade stainless steel are one of the safest material for food or water storage at high or cold temperatures.
while Copper bottles aren’t recommended to store hot or cold water as read here. Copper bottles can also get dark stains because of oxidisation and some studies have seen too much copper in bottles to cause diarrhoea , vomiting etc.
Plastic is notorious for being extremely harmful and toxic to life on earth and can harm our health in various ways.
This is the reason we currently deal only in Stainless Steel bottles.