Murphy explains that the chemist who developed Repuls was actually working on a way to prevent mold from growing in animal feed when he developed the formula for Repuls, which means it had to be safe for livestock to consume. Its ability to temporarily incapacitate humans on contact with their eyes and skin was a secondary discovery.
In 2020 after watching police response to the George Floyd riots, Murphy approached Crowe with a plan to turn Repuls into a police tool. He says he knew officers needed a better chemical irritant spray. “In 20 years in law enforcement, I never once used my pepper spray,” he says. “All the cleanup, all the messy decontamination, all the stuff that went along with taking the person to the hospital, I didn’t want to deal with it. So I went right from verbal commands to hands on.”
Murphy says Repuls causes the effects law enforcement needs from a chemical irritant without the unwanted effects of other chemical sprays.
First, it doesn’t cause respiratory impact to the subject. “There’s not a police agency in America right now that wants somebody in custody screaming they can’t breathe,” Murphy says. “What our product does is cause involuntary closure of the eyes. I don’t care who you are or how tough you are, your eyes will close.” It also causes a burning sensation on the skin and a feeling of disorientation.
Second, it does not cause any long-term effects. Murphy says because Repuls was developed for the SentriZone school shooter response system, it was designed not to harm the sensitive eyes of six-year-olds.