Acute exposure to hydrazine reported to four United States regional poison centers: reconsidering a paradigm

Abstract

Introduction

Exposures to hydrazines occur during aeronautic and space operations and pose a potential risk to personnel. Historically, extensive preparatory countermeasures have been taken due to concern for severe toxicity. This study seeks to better understand manifestations of acute occupational exposures to hydrazine to guide recommendations for management.

Materials and methods

A retrospective database review of records from four United States regional poison centers was conducted of all human exposures to hydrazine, monomethylhydrazine, or 1,1-dimethylhydrazine over two decades. Following case abstraction, descriptive statistics were performed to characterize demographics, manifestations, treatments, and outcomes.

Results

One hundred and thirty-five cases were identified, and most were adult males exposed to inhaled hydrazine propellant vapors. Fifty-seven percent of patients were asymptomatic following exposure; otherwise, common symptoms were dyspnea, throat irritation, cough, ocular irritation, and headache. All patients were evacuated or received decontamination, with a few reports of symptomatic treatments, including oxygen supplementation and salbutamol (albuterol). Patients usually recovered quickly and were released after a brief healthcare facility evaluation or observed locally. No patients developed delayed symptoms. Symptoms of severe toxicity were not observed, and there were no deaths.

Discussion

Acute exposures to hydrazines during operations within the aerospace industry appear to be limited primarily to mucosal and mild pulmonary irritation without significant neurologic, hepatic, or hematologic toxicity. These findings are contrary to previously established expectations and may be related to low-level exposures or possibly due to current emergency countermeasures.

Conclusions

Care in occupational hydrazine exposure will focus on evacuation, decontamination, and symptomatic management of chemical irritant properties of hydrazines. It is reasonable to manage mild cases outside of a healthcare facility. Continued endeavors in human space exploration and habitation will increase the risk of these exposures, making it imperative that clinicians be comfortable with the care and management of these patients.

Keywords:

• Aerospace
• industrial toxicology
• monomethylhydrazine
• monopropellants
• occupational health
• space toxicology

Acknowledgements

Data from a single region were presented at the North American Congress of Clinical Toxicology, 2023, in Montreal, QC, Canada.

Author contributions

HN conceptualized the study, coordinated multiple IRB exemptions with coauthors, performed statistical analysis, and drafted the manuscript; HN and CH acquired and abstracted data from the first poison center; HN, CM, and JC acquired and abstracted data from a second poison center; CN and SV acquired and abstracted data from a third poison center; BW acquired and abstracted data from a fourth poison center region. All authors provided review and revision of the manuscript. HN takes responsibility for the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data that support the findings of this study are available from the corresponding author, HN, upon reasonable request.

Additional information

Funding

There are no funding sources to declare for this manuscript.