Are the lids really plastic, and is that a problem?

Yes, the lids are polypropylene (#5 PP), BPA-free, with a silicone gasket. The glass body is what contacts hot food, so the safety case holds; just remove lids for the oven and vent them in the microwave rather than sealing hot food.

Can I go straight from freezer to oven?

No. Tempered glass resists thermal shock but is not immune — let containers temper toward room temperature first, remove the lid, and the glass body is rated to roughly 446°F / 230°C.

Is glass actually less leaching than 'BPA-free' plastic?

Glass is chemically inert. Peer-reviewed studies show plastic containers shed microplastics and migrate plasticizers/bisphenols when heated, while glass does not — and "BPA-free" plastics can still release substitute bisphenols.

Glass vs BPA-free plastic vs stainless: which food storage is safest?

Glass is inert: it will not leach bisphenols or shed microplastics, and it is both oven-safe (lid off) and microwave-safe while letting you see the contents. BPA-free plastic can still leach substitute bisphenols and shed microplastics, especially when heated, and is not oven-safe. Stainless is also inert but is neither oven- nor microwave-safe and hides the contents. Glass is the only option that is inert and works in both oven and microwave.

What's the catch with these Glasslock containers?

The one non-glass part is the lid: the snap-lock lids are polypropylene, so take them off for the oven and vent them in the microwave rather than sealing hot food. And tempered glass is heavy and can still break, so this set is not for backpackers, kids' lunches, or anyone needing the lightest possible containers.

Glasslock 18-Piece Assorted Oven Safe Container Set Review

What does the research say about the Glasslock 18-Piece Assorted Oven Safe Container Set?

Every claim below is tied to a source you can open, quoted verbatim — how we research picks.

“We found that food containers exposed to high-temperature released more than 10 million microplastics per mL in water.”

Heating plastic food containers releases millions of microplastic particles into water.
Microplastics released from food containers (PMC) · 2022 ↗
“by increasing the temperature from 40 to 95°C, the BPA migration increased four times in new baby bottles”

BPA migration from plastic containers rises steeply with temperature.
Bisphenol A release from food and beverage containers — a review (PMC) · 2023 ↗
“In general, it was observed that an increase in temperature caused an increase in the migration of phthalates into the simulant.”

Phthalate migration from plastic into food increases with heat.
Phthalate Migration to Food Simulants during Microwave Operations (PMC) · 2013 ↗

Educational summary of the research — not medical or veterinary advice. Evidence strength varies and individual results differ; talk to a qualified professional before changing your (or your pet's) health routine.

How does the Glasslock 18-Piece Assorted Oven Safe Container Set compare?

	Glass	Plastic (BPA-free)	Stainless
Leaches BPA/phthalates when heated	No (inert)	Can leach substitute bisphenols/plasticizers	No
Sheds microplastics	No	Yes, esp. when heated	No
Oven safe (body)	Yes (lid off)	No	No
Microwave safe	Yes	Yes	No
See contents	Yes	Yes	No

Buy it if

Meal-preppers who reheat leftovers in the microwave
Parents wanting plastic-free storage for kids' food
Oven-to-fridge cooks who bake and store in one dish
Anyone tired of stained, odor-holding plastic

Skip it if

Backpackers/kids who need unbreakable, lightweight gear
People who want oven-safe lids (these lids are not oven-safe)
Anyone needing the lightest possible containers (glass is heavy)

Is the Glasslock 18-Piece Assorted Oven Safe Container Set worth it?

A genuine low-tox upgrade: inert tempered glass for everything that touches hot food, with airtight snap-lock lids that beat typical plastic-lidded sets. Treat the polypropylene lids as plastic — off for the oven, vented in the microwave — and this is one of the best value glass storage sets you can buy.

Check price on Amazon Live price & reviews on Amazon

Questions, answered

Are the lids really plastic, and is that a problem?: Yes, the lids are polypropylene (#5 PP), BPA-free, with a silicone gasket. The glass body is what contacts hot food, so the safety case holds; just remove lids for the oven and vent them in the microwave rather than sealing hot food. Source Microplastics study (PMC) ↗
Can I go straight from freezer to oven?: No. Tempered glass resists thermal shock but is not immune — let containers temper toward room temperature first, remove the lid, and the glass body is rated to roughly 446°F / 230°C.
Is glass actually less leaching than 'BPA-free' plastic?: Glass is chemically inert. Peer-reviewed studies show plastic containers shed microplastics and migrate plasticizers/bisphenols when heated, while glass does not — and "BPA-free" plastics can still release substitute bisphenols. Source Phthalate migration (PMC) ↗
Glass vs BPA-free plastic vs stainless: which food storage is safest?: Glass is inert: it will not leach bisphenols or shed microplastics, and it is both oven-safe (lid off) and microwave-safe while letting you see the contents. BPA-free plastic can still leach substitute bisphenols and shed microplastics, especially when heated, and is not oven-safe. Stainless is also inert but is neither oven- nor microwave-safe and hides the contents. Glass is the only option that is inert and works in both oven and microwave.
What's the catch with these Glasslock containers?: The one non-glass part is the lid: the snap-lock lids are polypropylene, so take them off for the oven and vent them in the microwave rather than sealing hot food. And tempered glass is heavy and can still break, so this set is not for backpackers, kids' lunches, or anyone needing the lightest possible containers.