Distilled Water: The Complete Guide

Water distillation replicates the natural hydrological cycle — the same process by which the Earth has purified water through evaporation and rainfall for billions of years. A home water distiller mimics this cycle in a controlled, enclosed environment.

The distillation process is effective against an exceptionally broad range of contaminants. Unlike filtration methods that target specific categories of pollutants, distillation works on the fundamental principle that pure water vapor leaves virtually everything else behind.

The EWG's 2025 Tap Water Database, compiled from data across nearly 50,000 US water systems, identified 324 distinct contaminants in American drinking water. The database found that PFAS "forever chemicals" are present in the drinking water of over 143 million Americans, and that hexavalent chromium (chromium-6) — a known carcinogen — reaches more than 260 million Americans' taps despite having no federal limit.

PFAS — per- and polyfluoroalkyl substances — are a class of more than 10,000 synthetic chemicals used in industrial manufacturing, food packaging, non-stick cookware, firefighting foam, and hundreds of other applications. They are called "forever chemicals" because they do not naturally break down in the environment or in the human body. They accumulate over time.

In April 2024, the EPA finalized the first-ever National Primary Drinking Water Regulation establishing legally enforceable maximum contaminant levels (MCLs) for six PFAS compounds, including PFOA and PFOS, set at 4 parts per trillion. The EPA estimates that once fully implemented, the rule will prevent thousands of deaths and reduce tens of thousands of serious PFAS-attributable illnesses annually.

Why distillation is uniquely effective against PFAS

PFAS compounds have boiling points that are substantially higher than water — typically ranging from 200°F to over 400°F above water's boiling point. When water is boiled in a distillation chamber, PFAS compounds remain in liquid phase and do not vaporize. They are simply left behind. This is a fundamental physical separation that does not rely on filter media, membrane integrity, or regular maintenance to work correctly.

Independent laboratory tests have demonstrated PFAS removal rates exceeding 99.9% for commonly detected compounds including PFOA and PFOS. H2O Labs distillers pair the distillation process with an activated carbon post-filter to capture any shorter-chain PFAS that may have boiling points closer to water's, providing a complete two-stage barrier against forever chemicals.

Microplastics are plastic particles smaller than 5 millimeters — and often microscopic in size — that have entered the environment through the degradation of larger plastic items, synthetic textile washing, and industrial processes. Research has found them in oceans, rivers, groundwater, rain, soil, and increasingly in human tissue including the lungs, liver, and bloodstream.

A widely cited study by Orb Media, conducted in collaboration with the University of Minnesota School of Public Health, tested 159 tap water samples from across 14 countries and found that 83% were contaminated with plastic fibers. The United States had the highest contamination rate of any country tested, at 94%.

A separate 2018 study by Orb Media found that 93% of bottled water samples also contained microplastics — in some cases at higher concentrations than tap water — partly because the repeated opening and closing of plastic screw caps generates approximately 500 microplastic particles per twist.

The EPA flagged microplastics as priority drinking water contaminants in 2026, acknowledging that plastic particles have been found accumulating in human organs. Research to date raises concerns about chemical leaching (microplastics can carry BPA, phthalates, and heavy metals), cellular disruption, and inflammation.

Home water purification encompasses several distinct technologies. Each makes different trade-offs in terms of contaminant coverage, maintenance requirements, cost, and purity of output. Here is how distillation compares to the most common alternatives.

Reverse osmosis is often positioned as distillation's closest competitor — and it does produce high-quality water. However, RO systems require professional installation and plumbing connections, produce significant wastewater (typically 3–4 gallons of reject water for every gallon produced), require periodic membrane replacement, and can allow volatile organic compounds to pass through since VOCs are not rejected by the membrane the way dissolved solids are.

Distillation with a carbon post-filter addresses both dissolved solids and VOCs in a single, self-contained unit that requires no plumbing, no installation, and no specialized maintenance beyond regular cleaning.

Many people turn to bottled water under the assumption that it is cleaner and safer than tap water. The evidence suggests this assumption is often incorrect — and always expensive.

Bottled water purity: The FDA, which regulates bottled water, allows it to meet standards equivalent to EPA tap water standards — not higher. Much bottled water is sourced directly from municipal tap water supplies and receives only minimal additional treatment. There is no mandatory federal testing for PFAS in bottled distilled water.

Microplastic contamination: A 2018 Orb Media investigation tested 259 bottles from 11 brands purchased in nine countries and found that 93% contained microplastics. The Environmental Working Group notes that the repeated twisting of plastic screw caps alone generates approximately 500 microplastic particles per opening, contributing significantly to contamination levels in bottled water.

Cost: Bottled water retails at $1–$3 per gallon or more. A home water distiller produces water for approximately $0.30–$0.45 per gallon in electricity costs, plus the minimal cost of a carbon post-filter. A typical distiller pays for itself within months of regular use and continues generating savings for the entire life of the unit.

Environmental impact: The US generates enormous volumes of single-use plastic waste from bottled water. Home distillation eliminates this waste stream entirely — the water is made fresh, on-demand, and stored in reusable glass or stainless steel.

Yes. Distilled water is safe for daily drinking and has been consumed by people around the world for generations. It is the same grade of water used in medical procedures, dental care, laboratory experiments, and pharmaceutical manufacturing — precisely because its purity is guaranteed.

The most common question about distilled water concerns minerals: since distillation removes dissolved minerals along with contaminants, does drinking it cause mineral deficiency? The answer, supported by the World Health Organization and mainstream nutritional science, is no — for two reasons.

First, the minerals removed by distillation (calcium, magnesium, and others) are inorganic dissolved minerals. The human body absorbs minerals most effectively from food sources, not from water. Dietary intake from vegetables, fruits, dairy, nuts, and other foods provides the overwhelming majority of daily mineral requirements. The contribution of drinking water to total daily mineral intake is generally small.

Second, for those who prefer to supplement, H2O Labs offers a range of electrolyte and trace mineral drops designed specifically for use with distilled water. A small amount added to each glass provides a measurable mineral boost without compromising water purity.