Abstract: The invention presented here establishes the use of a dialkyl ketone peroxide as a sterilizing, antiseptic, disinfecting and anti-parasitic agent, with no apparent toxicity nor ecotoxicity, and a very wide spectrum of activity in terms of the type of organisms on which it acts (bacteria, virus, fungi, spores, mycobacteria, protozoa, algae, prions, arachnids, mites, insects, etc.), and in terms of the type of applications in which it can be employed (human and animal therapy, hygiene, packing, medical and industrial instruments, sanitary surfaces and healthcare environments, premises, surfaces in general, industrial installations, refrigeration towers, sanitary hot water systems, purification of drinking water for human or animal consumption, etc.). Likewise, the current invention illustrates the use of a composition comprising such dialkyl ketone peroxides.