Best Plastic-Free Food Storage 2026: Glass, Steel & Silicone Ranked

What the Nebraska study actually measured

The study behind most “don't microwave plastic” advice is Hussain et al. (2023, Environmental Science & Technology), from the University of Nebraska–Lincoln. The researchers tested two polypropylene baby-food containers and one polyethylene reusable food pouch, filled with water or 3% acetic acid (standing in for watery and acidic foods), and heated them at full power for three minutes in a 1,000-watt microwave.

• Some containers released up to 4.22 million microplastic and 2.11 billion nanoplastic particles from one square centimetre of plastic within three minutes. That is a per-area, worst-case figure; the paper does not give a per-container total.
• Microwaving released more than any other use they tested.
• Storage in the fridge or at room temperature for six months also released millions to billions of particles.
• The polyethylene pouch released more than the polypropylene tubs.

The study did not compare BPA-free and BPA-containing plastics; neither polypropylene nor polyethylene is made with bisphenols. A 2024 letter in the same journal argued that part of the microwave result may reflect the containers overheating, and the authors replied. The direction of the finding is not in dispute: heat plus plastic is the combination to avoid. More on this in microwaving plastic containers.

Materials compared

The glass types are explained in borosilicate vs soda-lime glass and Pyrex vs Anchor Hocking. Is silicone a plastic? Not chemically; see is silicone a microplastic.

Recommended picks

Materials, lids and heat limits below are taken from each maker's own product pages and care instructions, checked on 21 September 2026.

Glass: borosilicate

• OXO Good Grips Smart Seal glass (4-, 8-, 12- and 16-piece sets). Borosilicate glass; OXO says it can move from freezer to a preheated oven or microwave. The locking lids are plastic with a removable gasket, so they stay out of the oven.
• Anyday. A borosilicate dish with a glass lid, platinum silicone gasket and stainless rim, so nothing plastic touches the food. Anyday rates the bowl oven-safe to 500°F and the lid to 400°F.

Glass: everyday storage

• Anchor Hocking TrueSeal. Tempered soda-lime glass, made in the USA, with BPA-free plastic lids. Anchor Hocking says not to go straight from freezer to oven or microwave: thaw first. Dishes are oven-safe to 425°F without the lid.
• Pyrex Simply Store. Pyrex describes it as tempered glass, with BPA-free plastic lids that must not go in the oven. Pyrex's rule is “DO NOT transfer directly from freezer to hot oven.”
• Glasslock. Tempered soda-lime glass made in Korea, with polypropylene locking lids and silicone gaskets. Its “Oven Safe” range also uses polypropylene lids, so the lid never goes in the oven.

Stainless steel

• LunchBots Cinco. Five compartments, 18/8 stainless inside and out, including the lid. Not leakproof; the optional snap-on cover is plastic.
• PlanetBox Rover. Four compartments plus a treat spot. The tray is 18/8 (304) stainless and the lid 18/0 (430), which is why the decorative magnets stick. The small dipper cups have silicone tops.
• ECOlunchbox Three-in-One. Three nesting containers with no plastic gaskets, so not leakproof. ECOlunchbox lists it as 201 stainless, a lower-nickel grade than the 304 most brands use.
• U-Konserve. 304 (18/8) stainless containers with platinum-grade silicone lids.

Packing for school? The back-to-school microplastics guide ranks lunch containers, bottles, pouches and supplies by how much each one contributes.

Silicone (best for cold and freezing)

• Stasher Stand-Up Mid (56 fl oz). Platinum, food-grade silicone. Stasher lists it as microwave-, freezer- and dishwasher-safe, and oven-safe to 425°F.
• Zip Top. 100% platinum silicone, self-standing. Zip Top claims microwave, dishwasher and freezer use.
• Lékué. Platinum silicone bags from a Barcelona-based company; the products are made in China.

Silicone does not shed microplastics in the usual sense, but it is not inert either. Studies of silicone baking moulds found cyclic siloxanes migrating into food, most into fatty food, at baking temperatures, and in the first uses; moulds the maker had post-cured released far less (Helling et al. 2010; Zhu et al. 2025). A US FDA test found none in milk at 40°C. Cold storage is the low-risk use. Wash new silicone before first use, and don't bake fatty food in a brand-new silicone item.

Freezing without plastic

• Glass is freezer-safe for all the brands above. Leave room for food to expand, and let hot food cool before it goes in: Pyrex says to let hot glass cool before refrigerating or freezing.
• Thaw before heating unless the glass is sold for freezer-to-oven use. Pyrex also warns its plastic lids are brittle when frozen and can crack.
• Silicone bags and trays are the flexible option. Souper Cubes trays are platinum-cured silicone with a steel wire in the rim; the lids are plastic.
• Watch the lids: Ball's one-piece stainless storage lids and Weck's wooden lids are not meant for the freezer.

Lids: where the plastic usually is

Most glass sets come with polypropylene or other plastic lids. The lid touches food mainly at the rim and through condensation, so the practical rule is simple: never microwave or bake with the plastic lid on, and let hot food cool before you close it. If you want no plastic at all:

• Weck jars: a glass lid, a natural rubber ring and two stainless clamps. Weck also sells acacia wood lids (fridge, not freezer).
• Anyday: a glass lid with a silicone gasket and steel rim.
• Silicone lids: Charles Viancin lids seal by suction on a smooth rim (oven-safe to 428°F per the brand). Food Huggers covers are food-grade silicone; their “Lids” version has a glass window.
• Mason jar canning lids are tin-plated steel with a plastisol sealing compound underneath (BPA-free, per Ball). That compound is plastic, so keep food from touching the underside of the lid.

What popular containers are made of

Brand-by-brand detail: Rubbermaid, Tritan, Tupperware and Ziploc bags.

Quick wins

• Reheat in glass or on a plate, never in the plastic tub the food came in.
• Move leftovers into glass before they go in the fridge, since plastic sheds slowly in storage too.
• Use wide-mouth mason jars for dry goods and soups, and keep the food off the lid.
• Use silicone bags for the freezer and marinades, and glass or steel for anything hot.

See related: microplastics in plastic containers and best non-toxic cookware.