Eli5 If warm water is generally better for cleaning things, including our skin, then why do we use cold water to brush our teeth?

Question

Eli5 If warm water is generally better for cleaning things, including our skin, then why do we use cold water to brush our teeth?

In: 14

Answer 1

It isn’t generally advised to ingest the water from hot taps because they have a greater chance of containing harmful contaminants like lead and nickel (depending on plumbing, of course). Unlike the cold water supply, hot water spends time sat in boilers or hot water tanks within the home, which also increases contamination risk.

You could of course boil a kettle and mix it with cold water to clean your teeth, but that is less convenient. In any case, toothpastes are designed to be used with cold water, and the cleaning difference is probably minimal anyway.