While not common, reactive ground is potentially a highly dangerous and frequently misidentified hazard. A runaway reaction between sulphide minerals and ammonium nitrate can lead to the spontaneous and premature detonation of one or more blast holes at any time from a few minutes to several days after loading.

Hot ground is rock heated to more than 55 degrees due to chemical, geothermal or combustion processes. Although easier to detect, it presents a similar hazard to reactive ground if not managed. Blasting in hot and/or reactive ground requires a systematic and planned approach involving measuring and classifying ground and then implementing products and procedures to reduce unplanned detonation risks. Special training and supervision is required for blast crew personnel, and detailed scenario planning is required to cover delay and breakdown events.