Prenatal and postnatal infants have very weak immune systems, so the purity and safety of the water they ingest are extremely important. Typical chlorine or UV-light disinfection methods used by municipalities and bottlers are ineffective at eliminating the toughest bacteria and pathogens from tap and bottled water. Bottled water, although an essential disinfection method for preparing baby formula, can concentrate some harmful chemicals like nitrates or lead. Bottled and tap water often contain carcinogenic disinfection by-products like bromate or tri-halomethanes (THMs), which have been associated with adverse pregnancy outcomes, including miscarriages, birth defects, and low birth weights.