​​This presentation will review the dangers associated with peroxidizable chemicals. This is a class of hazardous materials that typically don’t require emergency plans as they screen out of the requirement for further analysis based upon DOE O 151.1D quantity thresholds, but present unique risks to responders. When exposed to air, these chemicals oxidize and form crystals. When the chemical or container is exposed to thermal or mechanical shock, the material can become explosive. Discussion will include physical and health impacts, identification of materials, forms of detection that can be used safely by responders, and best practices for response.