there is a risk of infection if the water is not sterile or the device is not cleaned after use. if the device is used improperly this can be harmful. in fact, proper application suggests the use of boiled water or saline water. in 2018, a patient was reported to have contracted "balamuthia mandrillaris" after using tap water during nasal irrigation. rare cases of fatal naegleriasis have occurred due to nasal insufflation of the amoeba "naegleria fowleri" from untreated tap water.