To deactivate is to switch a system, piece of equipment, or process off or into an inactive state so it stops being ready to operate. In a food plant the word covers everything from powering down a line at the end of a shift to taking a faulty metal detector out of service until it is repaired and revalidated. The concept also reaches into food science itself: enzymes are deactivated by heat during blanching and pasteurisation, and microorganisms are deactivated — killed or rendered unable to grow — by sanitisers, irradiation, or adequate cooking. In each case deactivation is deliberate and verifiable, which is why procedures record who deactivated what and when. The opposite state, active or validated, means the equipment or system is proven ready — a distinction that quality systems and safety audits take seriously.