A multi-part sterilant system (12) comprising: a first part (4) comprising a first reagent in a carrier medium in a first container (6); a second part (8)comprising a second reagent in a carrier medium in a second container (10); wherein the first reagent and the second reagent will react to provide a sterilising composition when the first part (4) is mixed with the second part (8); a pump head (2) having a peristaltic pump member (22); the first container (6) having a first-part dispensing tube (16) extending from its interior and disposed through the pump head (2); the second container (10) having a second-part dispensing tube (18) extending from its interior and disposed through the pump head (2); wherein the peristaltic pump member (22) when actuated acts on both the first-part dispensing tube (16) and the second-part dispensing tube (18) so as simultaneously to pump substantially equal volumes of the first part (4) and the second part (8).