Do plastic containers really shed microplastics?

Heavily-scored or microwaved plastic containers shed measurable particles, especially with hot or fatty food. A 2023 study from the University of Nebraska measured millions of particles released from microwaved baby-food containers. Cold storage of dry food in newer plastic is a much smaller exposure pathway.

Borosilicate or tempered glass?

Borosilicate (Pyrex original, Glasslock) handles thermal shock better — stovetop-to-fridge moves are less likely to crack it. Modern 'Pyrex' (different formulation) and most generic tempered glass are fine but slightly less forgiving.

Which set should I actually buy?

Glasslock or Pyrex with snap-lock lids and silicone gaskets. Avoid sets where the lid is bonded to the glass — they fail at the seal.

Glass vs plastic food storage: is it worth switching?

The “should I switch all my food storage to glass” question has gotten a lot of marketing-driven energy in the last few years. Here’s the honest version, separated from the noise.

The short answer

Yes — slowly, as your existing plastic containers wear out. There’s no need to throw out functional storage. There’s also no need to spend $200 on a panic-buy of a new set.

The case is real but specific: scratched or microwaved plastic containers shed microplastic particles, especially with hot or fatty food. A 2023 University of Nebraska study measured millions of particles released from microwaved baby-food containers — the kind of headline number that’s worth taking seriously even with the standard caveat that we don’t yet know exactly what dose-response means for human health.

Cold storage of dry food in newer, unscratched plastic is a much smaller deal.

The honest case for glass

No microplastic shedding from heat or scratches. Reheating in glass is the same exposure as reheating on a plate.
Doesn’t stain, doesn’t hold odor. Tomato sauce in glass after six months looks the same as tomato sauce in glass after one day.
Lasts longer. Plastic warps and fails. Glass either works or breaks — and “breaks” usually only happens to one container at a time.

Where plastic still wins

Weight. Glass containers full of soup are noticeably heavier. For lunchbox use with kids, this matters.
Drop tolerance. Concrete kitchen floor + glass container = mess.
Price for very large sets. A 24-piece glass set is meaningfully more expensive than the equivalent plastic.

What I’d actually do

Replace plastic containers as they fail or stain. Keep one or two plastic containers for travel, kid lunches, and dropping in the work fridge.

For a starting set, Glasslock is the one I keep recommending — dishwasher-safe, freezer-safe, the lids actually seal, and it’s been the consistent ATK pick for years.

What to skip

“Smart” glass containers with subscription apps. No.
Glass-and-plastic hybrid lids that say “glass” on the front of the box. The lid is the part that wears.
Marketing claims about “alkaline glass” or “structured glass.” Not a real thing.