Reverse osmosis and distillation are the two highest-performing consumer technologies for PFAS removal, and both are appropriate for households seeking maximum protection. A detailed comparison helps consumers choose based on their specific situation and priorities.
Mechanism and Performance
RO uses pressure to push water through a semipermeable membrane that physically rejects PFAS molecules based on size and charge. Distillation heats water to boiling and collects the condensed steam, leaving high-boiling-point PFAS in the boiling chamber. Both achieve 96 to 99.5% removal for long-chain PFAS. Distillation has a slight advantage for some short-chain compounds that may partially pass RO membranes, while RO is more effective for any volatile short-chain compounds that could co-distill with steam.
Water Production Rate and Volume
RO systems produce 50 to 100 gallons per day with tank storage, readily meeting household drinking and cooking needs. Countertop distillers produce 1 gallon per 4–6 hours — sufficient for modest consumption but inadequate as the sole filtered water source for larger families. Whole-house RO systems produce more than enough volume for all household uses but at significantly higher cost.
Operational Considerations
RO requires stable water pressure, periodic filter and membrane replacement, and produces reject water. Distillers require only electricity, produce no reject water, and need regular chamber cleaning but have minimal consumable costs. In power outages, neither functions — RO additionally fails during water pressure loss. For emergency preparedness, having backup certified pitchers or stored pre-filtered water supplements either technology.