Industrial microwave ovens are used in cooking, curing, drying and other processes where high energy must be delivered to moisture-laden product in a short period of time. Examples are cooking pork products, drying in paper processing, and curing adhesives in business forms manufacturing.

High electrical energy adjacent to conductive surfaces creates conditions favorable to spark production much as lightning occurs in a thunderstorm. Sparks result from a discharge of electrical energy. They generate heat and light. Light is broad spectrum white light, but has energy concentration in the near infrared region characterized by the oxidation of the natural atmosphere to produce ozone.

Sparks can produce substantial damage to products in process as energy release can lead to combustion. Microwave ovens are often equipped with spark detection sensors and automatic shut-down/product evacuation measures to prevent sparks from initiating combustion.