Individual breastmilk bottles and storage containers commonly range from about 6 fl oz up to 24 fl oz. Portable coolers and thermos-style chillers for day use often hold roughly 16–20 fl oz.
Several product designs keep the cooling element isolated from milk by using removable or separate gel/ice packs, or by positioning packs around external bottles so the ice or gel does not contact the milk directly.
Product details generally advise sterilizing before first use (for example, boiling in water for about 3–5 minutes) and then cleaning or sterilizing after each use—steam sterilizer or brief boiling are commonly recommended. Listings also warn against bleach and harsh scourers and note that some parts are dishwasher-safe.
Listings commonly state that milk-contacting bottles or containers are dishwasher-safe, while insulated or stainless-steel components may recommend hand washing. A few products stress minimizing milk-contacting parts to make cleaning easier.
