The most common life-threatening complications from both blunt and penetrating thoracic injury are hemothorax, pneumothorax, or a combination of both. New guidelines, set out by the Tactical Combat Casualty Care (TCCC), advises that vented chest seal dressings are used to manage open or sucking chest wounds. Designing out risk is a fundamental criterion for ensuring the optimal performance of a device is obtained that offers the casualty the greatest chance of survival. Two key areas of risk in the application of vented chest seal dressings are adhesion failure and vent failure. This study assesses a new design of vented chest seal dressing for both adhesion and vent profile. The development of this new design for a vented chest seal has been tested for adhesion and venting properties and shown to have performance criteria suitable for the treatment of open pneumothorax and design features that minimize the risk of product failure during use.