Before using the Spectra S1 Plus or S2 Plus breast pump for the first time, disassemble and wash in warm, soapy water all parts that come into contact with the breast and breastmilk. And then after every use, disassemble and wash all parts that come into contact with the breast and breastmilk (breast shield kit, valve head, membrane nipple, nipple cover, disk, and cap) in warm water with mild soap. All parts in the pump kit are dishwasher safe. Just remember to place items on wash cycle on the top rack and air dry. Do not use heat dry. Or you can also rinse them in clean water, air-dry and keep and cover them until next use.