Distillation is one of the oldest and most effective water purification methods available to consumers. By boiling water and condensing the steam, distillers leave behind contaminants that do not volatilize — including most PFAS compounds. However, distillation has practical limitations that make it a niche solution despite its effectiveness.
How Distillation Removes PFAS
Most PFAS compounds have very low vapor pressures and high boiling points. When water is heated to boiling, PFAS molecules remain in the liquid phase rather than volatilizing with the steam. The condensed distillate is therefore largely free of PFAS. Studies have shown distillation to achieve PFAS removal rates exceeding 99% for common long-chain compounds like PFOA and PFOS.
Limitations of Distillation
Distillers are slow — typically producing 1 gallon every 4 to 6 hours — and energy-intensive. Operating a countertop distiller continuously for a family’s drinking water needs can add meaningfully to electricity costs. Some very short-chain, highly volatile PFAS compounds may co-distill with water vapor and appear in the distillate, though this is a minor concern for most water supplies. Additionally, distillation removes minerals from water, producing flat-tasting water that some consumers find unpalatable without remineralization.
Best Use Case
Distillation is a strong choice for households needing high-confidence PFAS removal without ongoing filter replacement costs, particularly where water usage for drinking and cooking is modest. Combining a distiller with a small activated carbon post-filter addresses both the taste concern and any residual volatile compounds, providing comprehensive protection.