We Asked Experts Whether Drinking Days-Old Water Is Dangerous – And Their Answer Was Surprising

I regularly drink from stray glasses of water I see scattered around my house that were poured the day before. I think I’m being efficient and resourceful, but am I being safe? 

Experts say there is actually a tipping point at which it is better for your health to dump that glass of water and start afresh. 

Kristen Smith, a dietitian and spokeswoman for the Academy of Nutrition and Dietetics, said that she personally follows a 12-hour rule for a glass of water. After 12 hours, Smith will pour it out and drink a new glass.