Nasal Rinsing Works, and the Water You Use Can Kill You

Jala neti, rinsing the nasal passages with warm salt water, is one of the shatkarma, the six cleansing practices of hatha yoga. It has been absorbed into mainstream medicine as saline nasal irrigation, sold in every pharmacy, and recommended by ear, nose and throat specialists.

It is a rare case of a traditional practice crossing over almost intact. It also carries a specific and serious hazard, and the hazard is entirely about the water rather than the technique.

The rule, first, because it is the important part

Never use water straight from the tap.

The United States Food and Drug Administration is explicit. Use distilled or sterile water, or water that has been boiled for at least one minute and then cooled. Ordinary filter jugs of the Brita type do not make tap water safe for this purpose.

The reason is a free-living amoeba called Naegleria fowleri. It can be present at low levels in water that is entirely safe to drink, because stomach acid destroys it. Introduced into the nose, it can travel along the olfactory nerve into the brain and cause primary amoebic meningoencephalitis.

This is very rare. It is also very nearly always fatal. In the United States there were 164 reported cases between 1962 and 2023, with four survivors. Two deaths in Louisiana in 2011 were linked by the state health department to neti pot use with contaminated tap water.

Rare and nearly always fatal is an unusual combination, and it means the arithmetic is not about probability. Sterile water costs almost nothing and boiling costs a minute, and there is no benefit whatsoever to using tap water. There is simply no reason to accept the risk.

The rest of the safety instructions

Make the saline correctly. Roughly a level teaspoon of non-iodised salt per 500ml, sometimes with a pinch of bicarbonate of soda. Plain water without salt stings badly, because it is hypotonic relative to the tissue and draws water into the mucosa.