Glasslock · Food Storage Containers
Glasslock Oven and Microwave Safe Glass Food Storage Containers Set
Lower PFAS concern, glass containers themselves are inherently safe; lids warrant scrutiny but no red flags identified.
Glasslock's primary storage containers are borosilicate glass, a material with no known PFAS risk. The concern lies in the plastic or silicone lids and seals, the brand does not disclose their composition or PFAS status.
Shop Glasslock on Amazon →Material
borosilicate glass with silicone or plastic lids
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Category baseline
food packaging is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
Uncoated safe material
Bare, uncoated material (cast iron, stainless, carbon steel, or glass) with no surface treatment to contain PFAS.
The full breakdown
What it's made of and why it matters
Glasslock containers use borosilicate glass, a type of glass formulated with boron oxide that makes it resistant to thermal shock and chemical leaching. Borosilicate is one of the safest materials for food contact because it does not leach metals, BPA, or other chemicals into food at any normal temperature. The lids are typically silicone or polypropylene plastic; silicone is inert and food-safe, while polypropylene (plastic #5) does not contain BPA and is considered low-risk for leaching under standard microwave and refrigerator conditions.
The brand's record and disclosure
Glasslock is a South Korean brand owned by Hankook Chemicals and has no major recalls or safety controversies on public record. The company does not publish detailed transparency reports on material sourcing or third-party testing, which is typical for mid-market food storage brands. No evidence of certification claims (such as BPA-free labeling) is widely documented, though the inherent chemistry of borosilicate glass and polypropylene negates the need for such assurance. The brand maintains a silent stance on PFAS, which is common for glass container manufacturers since the glass itself is PFAS-free; concern centers only on lid coatings or seals, which appear not to be treated with PFOA or similar compounds based on available product information.
How it compares in its category
Borosilicate glass containers are among the safest options in the food storage category, alongside other glass brands like Pyrex and Anchor. They outperform plastic food storage containers (which may leach BPA, BPS, or phthalates) and ceramic or glazed containers (which can contain lead or cadmium in glazes). Glasslock's pricing and durability are competitive; the main differentiator is lid material and seal integrity, which Glasslock addresses with silicone or high-grade plastic rather than foam or vinyl seals that degrade faster.
If you buy it
Store food at room temperature, refrigerator, freezer, microwave, and conventional oven temperatures up to the stated lid limit (usually 400F for silicone lids); do not use on stovetop or under direct flame. Inspect lids regularly for cracks, discoloration, or loss of seal; replace if the silicone becomes brittle or the plastic becomes warped, typically after 3-5 years of heavy use. Hand-wash lids separately rather than dishwasher cycling to extend lifespan. Borosilicate glass is durable and will not degrade chemically; any replacement is purely mechanical.
Beyond PFAS: other things we checked
Established hazard classes for this product type, assessed from public information. These never change the PFAS grade; a Likely flag caps the Verdict at “Buy with care.”
Lid degradation and seal failure
Silicone and polypropylene lids are durable but degrade over time with heat cycling and dishwasher exposure. Degraded seals may allow food to absorb odors or lose freshness, though no chemical leaching is expected from silicone or PP at normal use temperatures.
Microplastic shedding from plastic lids
If lids are polypropylene rather than silicone, mechanical wear or prolonged heating could theoretically release microplastics, though this is not reported as a concern for Glasslock containers under normal use.
Glass thermal shock and breakage
Borosilicate glass is thermally stable, but rapid temperature swings (e.g., hot container to ice water) can still cause cracking or shattering. This is a mechanical safety hazard, not a chemical leaching risk.
Heavy metal leaching from glass
Borosilicate glass does not leach lead, cadmium, or other heavy metals under any normal cooking or food storage condition. No reports of contamination from Glasslock containers.
BPA or phthalates in lids
Polypropylene lids do not contain BPA by formulation, and phthalates are not used in food-grade silicone or PP. No evidence of these chemicals in Glasslock products from available disclosures or recalls.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 82% confidence. It is not a lab result.
No independent PFAS lab test is on record for this exact product. A lab test could move the score in either direction.
The brand has not made a specific, verifiable PFAS-free statement, so part of this score reflects that missing disclosure rather than a confirmed material.
Formulations and coatings change between production runs. Always check the current label before buying.
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borosilicate glass with non-PFAS lid
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More food storage containers grades
How we score: every product runs through the same public 0–100 rubric based on materials, coatings, brand disclosure, lab findings, and recalls. See the full methodology → Spotted a mistake? Report an error.