# Repurposing thiosulfate for chlorine gas exposure

> **NIH NIH R21** · NATIONAL JEWISH HEALTH · 2022 · $197,717

## Abstract

Chlorine gas is a chemical warfare agent and toxic industrial chemical (TIC) that produces respiratory failure and
edema due to chemical burns of the airway and alveolar epithelium. Chemical warfare agents are an important
threat to military personnel and civilians. The broad long-term goal of this project is to develop medical
countermeasures against chemical agents that produce a lung toxidrome. Chlorine gas and other TICs can
elevate oxidative damage leading to cellular injury and inflammation. Cellular injury from chlorine gas exposure
is believed to result from its rapid hydration that generates hypochlorous acid (bleach) and hydrochloric acid.
Sodium thiosulfate is an FDA approved treatment for cyanide poisoning, but also is used as an effective
dechlorinating agent. We hypothesize that the dechlorinating and antioxidant actions of sodium thiosulfate will
target hypochlorous acid and hypochloric acid generated during chlorine exposure along with other oxidants that
are produced during oxidative stress and inflammation associated with a chlorine gas exposure. We will test our
hypothesis with two specific aims. The first aim will develop a swine model of chlorine gas-induced acute lung
injury model. The second aim will optimize dose, dose regimen, and rescue window of sodium thiosulfate in this
swine model. These data will be used as proof of principle studies to support regulatory approval for the use of
sodium thiosulfate as a medical countermeasure for chlorine gas lung injury under the FDA animal rule. If
successful this FDA approved product could be rapidly developed as a medical countermeasure against chlorine
gas injury.

## Key facts

- **NIH application ID:** 10471264
- **Project number:** 5R21ES032951-02
- **Recipient organization:** NATIONAL JEWISH HEALTH
- **Principal Investigator:** Vikhyat S Bebarta
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $197,717
- **Award type:** 5
- **Project period:** 2021-08-18 → 2024-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10471264

## Citation

> US National Institutes of Health, RePORTER application 10471264, Repurposing thiosulfate for chlorine gas exposure (5R21ES032951-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10471264. Licensed CC0.

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