A case of lung injury due to a hydrogen explosion caused by the simultaneous use of two home folk remedies devices.
家庭用機器2台の同時使用による水素爆発で肺損傷に至った1例
Abstract
This case report documents, from an emergency-medicine standpoint, a hydrogen explosion that occurred while two home devices were used at the same time and resulted in lung injury. When ignition and explosion occur in an environment where a hydrogen-generating/inhalation device is in use, the harm is not confined to the device: it can extend via the inhalation route to a pulmonary contusion centred on the alveoli (combustion-type lung injury). Combining multiple devices created an unanticipated ignition condition, and serious trauma occurred even in the home environment. The case clinically corroborates the danger of operating devices whose output concentration is far above the empirically validated safe value for the inhalation environment.
Mechanism
Under hydrogen's very low minimum ignition energy, combined device use produced an unanticipated ignition source and mixing condition; combustion within the inhalation route reached alveolar-level injury.
Bibliographic
- Authors
- Tsuchikane M, Yamagiwa T, Takada T, Wakai S, Inokuchi S
- Journal
- Acute Med Surg
- Year
- 2024
- PMID
- 39634382
- DOI
- 10.1002/ams2.70019
- PMC
- PMC11614747
Tags
Delivery context
In air, molecular hydrogen is reported to be combustible across approximately **4% (LFL, lower flammability limit) to 75% (UFL, upper flammability limit)**. Among high-concentration hydrogen inhalers, 66% output sits inside this range, and even pure-hydrogen (100%) output forms a 4–75% concentration-gradient layer at the device–air boundary (the UFL 75% paradox). Engineering principle would therefore call for operation below LFL (the classical 4%); that figure, however, was measured under closed, pre-mixed, static conditions. For the open, dynamic inhalation environment, the empirical value reported in the literature is **10%**, which is the figure referenced in practice as the operating ceiling. The 66% / 100% output devices are recorded in the Japanese Consumer Affairs Agency accident-information database, and from these considerations are not recommended.
Safety notes
See also: