A report on test releases of liquefied compressed chlorine was published on Sept. 30 by Utah Valley University (UVU). Known as the “Jack Rabbit Project,” the multiagency chlorine release experiments were conducted in part to help emergency responders meet the planning, tactical and operational challenges of a catastrophic Toxic Inhalation Hazard (TIH) release. Staff from the U.S. Fire Administration’s National Fire Academy (NFA) participated in the project to identify training gaps and opportunities that the NFA’s hazardous materials curriculum can meet.
The Jack Rabbit Project’s scientific approach included emergency response objectives. Their inclusion allowed subject matter experts to validate long-practiced hazardous materials response strategies and tactics. Findings related to the emergency response objectives of the Jack Rabbit Project include:
- The 2016 Emergency Response Guidebook (ERG) isolation and public protective action distances are consistent with Jack Rabbit data.
- Sheltering in place is the best option if evacuation isn’t possible.
- Vehicles remained operational after exposure to high concentrations of chlorine. A lateral-to-the-wind escape from a chlorine plume is the best option for responders in vehicles.
- Electronics operated after exposure but long-term operability was inconsistent.
- Common urban materials were not greatly affected but heavy hydrocarbons dissolved and metal surfaces were immediately corroded.
- Photo Ionization Detectors with 11.7eV bulbs detected chlorine with reasonable accuracy.
- Predictive plume models are best used as planning/forecasting tools and not as emergency response tools.
- A risk-based response process that considers the container, stress/breach release, wind, exposures, and environmental conditions is critical to responder safety.
Aerial view of the plume behavior
During this 20 ton release trial, the small cone in the extreme bottom center of the photo was 50 meters upwind with a wind speed of 3.55 meters/second. Photo: Utah Valley University
Emergency responders need to base their planning and response decisions on facts, science and incident circumstances. For that reason, the authors of the report stated that it is important to involve the emergency response community in the planning and execution of future hazardous materials release research.
The Jack Rabbit Project test program began in 2010. The U.S. Department of Homeland Security’s Transportation Security Administration wanted to better understand the impact on communities of a large release (60 to 90 tons) of TIH gases (chlorine and anhydrous ammonia) from a rail car.
The project was divided into two phases — Jack Rabbit I and Jack Rabbit II — and a series of tests occurred between 2010 and 2016. The NFA will use information learned from the tests to update response protocols taught in our hazardous materials courses.
A repository of information on the complete Jack Rabbit Project is available to emergency responders on UVU’s website.