Supplementary Material for: Industrial Chlorine Gas Leak: Combined Ocular and Respiratory Injury in Two Patients — A Case Report

Introduction: Even though chlorine gas accidents are rarely seen, when an individual comes into contact with the gas, it can still cause considerable injury, particularly to the eyes and the airways. Chlorine is a strongly irritating and toxic gas, instantly recognizable by its sharp, suffocating odor and yellow-green color. It is widely used in industrial work and water purification, and has also been employed in certain conflict situations. The extent of harm caused by chlorine inhalation is largely determined by its moderate water solubility, which allows the gas to reach and irritate both the upper and lower parts of the airway. Once chlorine comes into contact with moist epithelial surfaces, it reacts with the mucus layer to produce hydrochloric acid and hypochlorous acid (HOCl). These substances can inflame or injure the conjunctiva and, though uncommon, may result in chemical burns or corneal epithelial defects. This process also triggers the generation of reactive oxygen species (ROS), which further amplify tissue damage. (5) In this report, we present two cases in which patients developed corneal injury, respiratory distress, and even third-degree periocular burns following acute chlorine gas exposure. Case Presentation: We report the cases of two male labourers, aged 22 and 43 years, who arrived at our centre within an hour after accidental chlorine gas exposure at a rubber manufacturing facility. Both experienced an abrupt decline in vision in both eyes, breathlessness, and third-degree burns affecting the periocular region. Ocular examination revealed grade 1 corneal burns as per the Roper–Hall classification and grade 1 injuries according to the Dua classification, with visible epithelial defects and patches of limbal ischaemia. Chest imaging indicated chemical pneumonitis in both individuals, with the younger patient displaying more severe lung involvement. Treatment was initiated immediately and involved extensive irrigation with a balanced salt solution, followed by the application of preservative-free topical antibiotics, lubricants, cycloplegics, a short course of topical corticosteroids, and fortified insulin eye drops. Systemic management included intravenous dexamethasone, oral doxycycline, and vitamin C. Both required supplemental oxygen and close respiratory observation due to their breathing difficulties. By the end of two weeks, both patients showed marked clinical improvement, with clear corneas, complete epithelial healing, better visual acuity, and progressive relief of respiratory symptoms. Conclusion: Chlorine gas exposure can lead to a combination of ocular surface burns and chemical pneumonitis. Even when the initial symptoms seem mild, patients may later develop notable eye surface damage and periocular skin injury. Early and generous irrigation, supportive ocular surface treatments, systemic anti-inflammatory therapy, and appropriate respiratory care all play crucial roles in recovery. These cases highlight the importance of early recognition and a team-based, multidisciplinary approach in managing chlorine-related injuries in the workplace.