Potassium bicarbonate (also known as potassium hydrogen carbonate or potassium acid carbonate) is a colorless, odorless, slightly basic, salty substance. According to the US Food and Drug Administration (FDA), potassium bicarbonate is "generally recognized as safe". Potassium bicarbonate is soluble in water, and is often found added to bottled water to affect taste; however, it is not soluble in alcohol. Decomposition of the substance occurs between 100 °C and 120 °C into K₂CO₃ (potassium carbonate), H₂O (water), and CO₂ (carbon dioxide). In concentrations greater than 0. 5%, KHCO₃ can have toxic effects on plants (potassium bicarbonate has widespread use in crops, especially for neutralizing acidic soil, and is also under consideration as an organic fungicide), although there is no evidence of human carcinogenicity, no adverse effects of overexposure, and an undetermined LD₅₀. Physically, potassium bicarbonate occurs as a crystal or a soft white granular powder. It is manufactured by reacting potassium carbonate with carbon dioxide and water: K₂CO₃ + CO₂ + H₂O → 2 KHCO₃. Potassium bicarbonate is very rarely found in its natural form, the mineral called kalicinite