Book excerpt: The U.S. Air Force is developing a model to assist commanders in determining when it is safe to launch rocket vehicles. The model estimates the possible number and types of adverse health effects for people who might be exposed to the ground cloud created by rocket exhaust during a normal launch or during an aborted launch that results in a rocket being destroyed near the ground. Assessment of Exposure-Response Functions for Rocket-Emmission Toxicants evaluates the model and the data used for three rocket emission toxicants: hydrogen chloride, nitrogen dioxide, and nitric acid.