NEW YORK (FOX 5 NY) - Do not use tap water in your neti pot or similar sinus wash device. Using tap water may be easy and convenient but something in it could literally kill you. It is very rare, but it happened to a woman in Washington State.
Dr. Clinton Coleman of Holy Name Medical Center in New York told Fox 5 that the death of a 69-year-old Seattle woman who frequently used a neti pot to clear her sinuses could have been avoided had she just used sterile distilled water, such as store-bought or boiled at home for five minutes.
The woman developed a quarter size rash on her nose. Then a seizure revealed a lesion on her brain. The lesion was the result of an amoeba. The woman filtered the water with a Brita filter, which she thought was good enough.
Dr. Coleman said that most such products filter large particles but don't filter out viruses, bacteria, or parasites. Boiled, sterile or distilled water is the preferred solution. You can also find special filters designed to remove microbes.
You should refer to the CDC's safety information about sinus washing.