The present invention relates to the use of a compound chosen from squalamine and a squalamine-analogue aminosteroid compound, as an agent for disinfecting an inert-material object, in particular the predisinfection of a medical, dental, diagnostic or surgical material. The present invention also provides an aqueous or water-soluble disinfecting composition which is beneficial for a use according to the invention, characterized in that it comprises, as disinfecting active compound, a said compound chosen from squalamine and a said squalamine-analogue aminosteroid compound which is antibacterial and antifungal, with excipients that are appropriate for a water-soluble or aqueous formulation.
