Understanding the Units — ppm and mM
🔹 Plain English FirstWhen you see a hydrogen-rich water product labeled “1.6 ppm H₂” or “0.8 mM H₂,” those numbers describe how much dissolved hydrogen gas is in the water. Parts per million (ppm) is a mass-based unit — milligrams of H₂ per liter of water. Millimolar (mM) is a mole-based unit. For H₂, 1 ppm ≈ 0.5 mM.
🔬 The ScienceFor dissolved H₂: 1 ppm = 1 mg H₂ per liter of water. Since the molecular weight of H₂ is 2.016 g/mol, 1 ppm ≈ 0.496 mM ≈ 0.5 mM. The atmospheric saturation concentration of H₂ in water at 37°C and 1 atm is approximately 0.8 mM (1.6 ppm). This is the maximum concentration achievable by simply dissolving H₂ at atmospheric pressure. Concentrations above 1.6 ppm require pressurized packaging to maintain the elevated dissolved H₂ against the equilibrium driving force.
🍃 Why It MattersUnderstanding the units and the saturation limit allows you to evaluate product claims critically. A product claiming 5 ppm dissolved H₂ in a standard plastic bottle is making a physically implausible claim — H₂ would permeate through the plastic and the concentration would drop to near zero long before consumption.
Concentrations Used in Research
🔹 Plain English FirstThe concentrations used in human clinical research on hydrogen-rich water provide a reference point for evaluating product claims. Most human studies have used concentrations in the range of 1–1.6 ppm (0.5–0.8 mM). This is the range that H2ForLife targets in its products.
🔬 The Science| Concentration Range | Context | Notes |
|---|---|---|
| 0.5–1.0 ppm (0.25–0.5 mM) | Lower range of human clinical research | Some studies; below atmospheric saturation |
| 1.0–1.6 ppm (0.5–0.8 mM) | Primary range of human clinical research | Most HRW studies; at or near atmospheric saturation |
| 1.6 ppm (0.8 mM) | Atmospheric saturation limit at 37°C | Maximum achievable without pressurized packaging |
| >1.6 ppm | Above atmospheric saturation | Requires pressurized packaging to maintain |
There is no established minimum effective concentration for any specific outcome in humans. The research does not yet support a precise dose-response relationship for dissolved H₂ in human clinical outcomes.
🍃 Why It MattersTargeting a concentration in the research-relevant range — and verifying that concentration through independent testing — is the basis for H2ForLife’s product quality standard.
Concentration at Consumption — The Relevant Metric
🔹 Plain English FirstA product’s dissolved H₂ concentration at the time of manufacture is not the same as the concentration at the time of consumption. H₂ escapes from water over time, and the rate of loss depends on packaging material, storage conditions, and time. The concentration that matters is the one the consumer actually receives.
🔬 The ScienceDissolved H₂ concentration decreases over time due to permeation through packaging materials and equilibration with headspace gas. Aluminum cans are impermeable to H₂ and maintain dissolved concentration throughout the product’s shelf life under normal storage conditions. Standard plastic bottles are permeable to H₂ — concentration loss begins immediately after filling and continues throughout the supply chain. See KA-008 — Packaging Science for the full analysis.
🍃 Why It MattersWhen evaluating a dissolved H₂ concentration claim, ask: when was the concentration measured? At the time of manufacture, or at the end of the stated shelf life? Under what storage conditions? The answer determines whether the claim reflects what the consumer actually receives.
Frequently Asked Questions
Is more dissolved H₂ always better?
The research does not yet support a clear dose-response relationship for dissolved H₂ in human clinical outcomes. Targeting a concentration in the research-relevant range (approximately 1–1.6 ppm) is the evidence-based approach. Claims of dramatically higher concentrations should be evaluated critically, particularly regarding packaging format and independent verification.
What concentration does H2ForLife target?
H2ForLife targets dissolved H₂ concentrations in the research-relevant range, verified through independent laboratory testing. Specific concentration data is available in our independent test documentation.
How does concentration relate to the research?
Most human clinical research on hydrogen-rich water has used concentrations in the 1–1.6 ppm range. H2ForLife targets this range because it is the concentration range studied in the peer-reviewed literature. See KA-003 — What Is Molecular Hydrogen? for the research overview.
