Organic peroxides are relatively unstable compounds which can decompose spontaneously and sometimes explosively.

Such decomposition can be caused by:

heat or fire: organic peroxides are thermally unstable and sensitive to heat. Above the SADT (Self Accelerating Decomposition Temperature) the reaction becomes uncontrolled and violent.

Organic peroxides are generally flammable and burn vigorously.

Decomposition can also be caused by hot material being added to an organic peroxide, or by the peroxide being put into a hot recipient.

mechanical effect: some organic peroxides are able to decompose as result of mechanical shock (impact and friction).

Thermal sensitivity and shock sensitivity are evaluated by standardized European tests