A $15 strip of vinyl and paper that changes colors when exposed to nerve agents, cyanide and other chemicals might protect police, firefighters and others who rush unprotected into a disaster.

The HazMat Smart Strip, inspired by decades-old military technology, will soon go into production at a West Virginia print shop, according to the Associated Press. Fire departments in New York and Florida already have ordered hundreds of the strips, according to the wire service.

The baseball card-sized Smart Strip can detect chlorine, pH, fluoride, nerve agents, oxidizers, arsenic, sulfides and cyanide in liquid or aerosol form at minute levels.

A change in color in any of the eight categories alerts emergency crews to get additional gear, decontaminate or evacuate. Hazmat experts say it's not precise, but a valuable low-tech early warning system.