About this page
A chronological grouping of four mutually related peer-reviewed papers on the concentration, device design, and accident record of hydrogen inhalation. Each entry summarizes what the paper itself reports; this page does not assert an independent conclusion. Consult the individual paper pages and the original abstracts for the primary source.
1. Kurokawa 2015 — comparison of delivery routes
PMID: 26504515 — Kurokawa et al., *Medical Gas Research*.
Compares molecular-hydrogen delivery routes (inhalation, hydrogen-rich water, oral, intravenous), examines the inhalation route from a systemic-uptake perspective, and notes the concentration and device-design questions specific to inhalation.
2. Kurokawa 2019 — device design and explosion prevention
PMID: 31552881 — Kurokawa et al., *Medical Gas Research*.
A device-design synthesis that distinguishes the closed-system LFL of 4% from the value relevant to the inhalation environment and discusses a safe-operating-concentration framework.
3. Ichikawa 2023 — accident-case synthesis and selection criteria
PMID: 36204781 — Ichikawa et al., *Medical Gas Research*.
Organizes cases from the Japanese Consumer Affairs Agency accident-information database into an account of the safety questions around high-concentration devices, and presents device-selection criteria for consumers.
4. Ichikawa 2026 — in-airway ignition mechanism
PMID: 41489350 — Ichikawa et al., *International Journal of Risk & Safety in Medicine*.
Analyzes the ignition mechanism in the respiratory tract and discusses operation at low concentration (≤ 10%).
Note on reading the four together
All four were published in peer-reviewed journals between 2015 and 2026 and address inhalation concentration from different angles — delivery route, device design, accident cases, and ignition mechanism. Assessment of the authors, their affiliations, and the conclusions is left to the reader against the primary sources; this page only organizes where the papers are and what they report.
Cited papers
https://h2-papers.org/en/safety-notes/lineage