Leakproof and airtight options include bottles with solid screw‑on caps, plastic containers with two‑latch airtight seals, and storage bags with reinforced double‑zipper seals.
Single‑use breast milk bags commonly list about 6 ounces; storage bottles often come in around 5 ounces, and some portable bottles hold about 11 ounces.
Many bottles feature clear ounce and milliliter markers to measure and track milk volume, and some storage bags also include graduated measurement markings.
Milk containers are commonly made from plastic (including polypropylene), silicone components, glass, and stainless steel.
Capacities range from small bottles and bags (about 5–6 ounces, with some portable bottles around 11 fl oz) up to large jars and pitchers (about 64–138 ounces); a 4.7‑cup food container is also listed.
Sealing options include reinforced double‑zipper and tamper‑evident tear‑away tops for bags; screw‑on or solid caps for bottles; two‑latch airtight lids (sometimes vented) for plastic containers; and metal or glass cover lids for jars and carafes.
Some breast milk bags are designed to freeze flat for faster, more uniform thawing and include reinforced side seams and double‑zipper seals; several bags are also pre‑sterilized.
