This invention comprises a light and portable chemical combination of reagents for sterilising or disinfecting objects in the absence of electrical or fire power. The chemical combination includes a chemical oxidant with the ability to release a biocidal intermediate, a chemical oxidant reducer capable of reaction with the oxidant and an effector to induce a reaction between the oxidant and the reductant. In one embodiment, the oxidant comprises chlorite, the reductant comprises sulfite and the effector comprises ascorbate. In another embodiment, the chemical combination comprises the oxidant, reductant, effector and magnesium activated with iron. When water or water solutions are added to any of the embodiments, the chemical combination generates heat, vapor and a biocide intermediate that can destroy contaminating microorganisms. In one embodiment, the biocidal intermediate is a halogen-based biocide intermediate, such as chlorine dioxide. In another embodiment, the biocidal intermediate is a halogen-free biocide intermediate.