There are multiple safe sources of drinking water and usually we pick based on taste, amount of packaging, or convenience.
- Tap water
- Fridge-filtered tap water
- Pitcher-filtered tap water
- Bought drinking water
- Bought spring water
- Bought distilled water
But if you’re going to use it for a sinus rinse (a.k.a. nasal lavage, jala neti) it’s safest to use either distilled water or drinking water that has been boiled and allowed to cool.
A recent article recommends twice-daily sinuses rinses to reduce risk of hospitalization after testing positive for COVID-19 and many of the people sharing it are conflating distilled water with other types of water available at the grocery store. I’ve been doing neti since about 1998 and I highly recommend it for a few different conditions.
Content Note: Creepy pathogen information follows. If weird medical stuff bothers you, close this tab now and don’t read further.
Some things survive municipal water treatment but they don’t hurt us when we drink them or bathe in them.
But the sinuses are close to the brain. (This is your last warning to stop reading to avoid the creepy stuff.) There’s an occasional news article about someone getting warm pond water up their nose then gradually dying from brain-eating amoebas. Confirmed cases of this are very rare, but I’m not confident that adults who were already sick with something else are ever checked for brain-eating amoebas so we don’t know how common this really is. Brain-eating amoebas survive the treatments drinking water goes through. So when you’re intentionally putting water up your nose, stick with water that you know is safe for drinking AND has been boiled.