The parts (minus the tubing and tubing adapters) should be submerged in boiling water for 3 minutes to sterilise them before your first use. Then after each subsequent use, we recommend that you disassemble the collection cups, silicone breast shields, valves, and valve bases, rinse them with cold water, and then hand-wash them in warm, soapy water. They should then be rinsed well and allowed to air-dry on a dedicated rack or clean cloth. Using sterilisers or harsh detergents can warp the delicate silicone pieces and should be avoided. UV sterilisation or cold sterilisation is acceptable though.