# Safety of hydrogen inhalers

Aggregated literature, accident records, and regulatory background on the safety of hydrogen inhalation. Safe concentration handling matters: the classical 4% LFL is a closed-system value; the empirical inhalation-environment ceiling is approximately 10%. See [the inhalation concentration explainer](/en/safety-notes/inhalation-concentration) for the rationale.

## Related papers (7)

- [Sixty-minute inhalation of molecular hydrogen decreases blood oxygen saturation but does not alter autonomic cardiac regulation at rest in healthy females: a randomized, double-blind, placebo-controlled crossover study.](/en/papers/41401441) — Can J Physiol Pharmacol 2026 — inhalation — mixed
- [Respiratory-physiology modeling of therapeutic hydrogen inhalation: defining the fraction of inspired hydrogen (FiH) and flow-rate requirements.](/en/papers/42050516) — Respir Res 2026 — inhalation — not assessed
- [Performance of Unmodified Mechanical Ventilators With 2% Hydrogen Gas Mixtures.](/en/papers/39969918) — Respir Care 2025 — inhalation — not assessed
- [Hydrogen inhalation: in vivo rat genotoxicity tests.](/en/papers/38432775) — Mutat Res Genet Toxicol Environ Mutagen 2024 — inhalation — null
- [Hinhalation therapy in patients with moderate COVID-19 (HCOVID): a prospective ascending-dose phase I clinical trial.](/en/papers/39016593) — Antimicrob Agents Chemother 2024 — inhalation — positive
- [Low-Flow Nasal Cannula Hydrogen Therapy.](/en/papers/33029275) — J Clin Med Res 2020 — inhalation — positive
- [A basic study on molecular hydrogen (H2) inhalation in acute cerebral ischemia patients for safety check with physiological parameters and measurement of blood H2 level.](/en/papers/22916706) — Med Gas Res 2012 — inhalation — positive

## Related safety notes

- [/safety-notes/inhalation-concentration](/en/safety-notes/inhalation-concentration)
- [/safety-notes/accident-cases](/en/safety-notes/accident-cases)
- [/safety-notes/lfl-ufl-explained](/en/safety-notes/lfl-ufl-explained)
- [/safety-notes/lineage](/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — https://h2-papers.org/en/topics/inhalers/safety