<i>S</i>-Nitrosothiols are ˙NO releasing agents renowned for vasodilatory and antioxidant properties. O<sub>2</sub>˙<sup>-</sup> promotes their decomposition, forming highly aggressive peroxynitrite ions (ONOO<sup>-</sup>). Since the production of O<sub>2</sub>˙<sup>-</sup> can be controlled by enzymes or by visible light, such otherwise harmless components can be turned into effective antimicrobial and nematicidal combinations with numerous potential applications in medicine.