Glasslock · Food Storage Containers
Glasslock Round Oven-Safe Food Keeper
Lower concern, glass and common plastics pose minimal PFAS risk, but brand silence is notable.
Glasslock's round oven-safe container is primarily borosilicate glass, which does not require PFAS coatings. The lid is likely polypropylene or silicone, neither of which typically contains PFAS.
Shop Glasslock on Amazon →Material
borosilicate glass with silicone or polypropylene lid
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
This container uses borosilicate glass as its primary food-contact material, which is chemically inert and does not leach under normal heating or storage conditions. The lid is either silicone or polypropylene, both of which are food-safe plastics with low migration risk at typical kitchen temperatures. Borosilicate glass is specifically engineered to resist thermal shock and acidic food degradation, making it more durable than soda-lime glass alternatives. The silicone or PP lid will not introduce BPA or phthalates in normal use, as neither plastic type relies on these additives.
The brand's record and disclosure
Glasslock is a South Korean brand with no published environmental health statements or third-party certifications (such as BPA-Free certification or NSF marks) readily available in English-language sources. The brand has not faced major food safety recalls or chemical contamination incidents that are publicly documented. However, the company's silence on PFAS and broader chemical testing policies makes independent verification of manufacturing standards difficult for consumers.
How it compares in its category
Glass food storage containers are among the safest options in the category because the material itself does not degrade or migrate chemicals into food. Compared to plastic-only alternatives (which carry BPA, phthalate, and microplastic risks) or ceramic containers (which may have lead-glazed rims), borosilicate glass with polymer lids represents a low-risk middle ground. Glasslock's pricing is competitive with Pyrex and other borosilicate brands, though Pyrex offers more transparent third-party testing disclosures.
If you buy it
Avoid rapid temperature changes (e.g., freezer to stovetop) despite borosilicate's durability, as thermal shock can still cause breakage. Do not use the container for prolonged heating above 220C (425F) to preserve the silicone lid integrity; hand-wash rather than dishwasher for longer lid lifespan. Replace the lid if it becomes cloudy, cracked, or loses seal performance, as this indicates material degradation. Clean the rubber seal regularly to prevent mold or odor buildup in humid storage.
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.”
BPA and phthalates in plastic lid
Polypropylene and silicone do not require BPA or phthalate additives to function. No contamination reports exist for Glasslock containers, and these polymers are stable at room temperature and normal microwave heating.
Glass breakage and sharp fragments
While borosilicate glass is impact-resistant, it can still fracture from drops or thermal shock. Broken glass poses a cutting and aspiration hazard, particularly in households with children. This is a mechanical hazard, not a chemical one.
Silicone lid degradation and leaching
Silicone can degrade over time with repeated heating, dishwasher cycles, or prolonged contact with oils and acidic foods, potentially releasing oligomers. The risk is low at typical use temperatures below 200C, but hand-washing extends lid lifespan and reduces migration.
Mold or bacterial growth in seal
The groove where the silicone or PP lid seats can trap moisture and food residue, creating environments for mold or bacterial biofilm if not cleaned thoroughly. This is a hygiene concern rather than a direct chemical hazard.
Lead in glass (historical concern)
Modern borosilicate food-storage glass does not contain lead as a component. Glasslock containers are manufactured to food-contact standards, and no lead contamination has been reported for this brand or product line.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 78% 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.
Safer alternatives in Food Storage Containers
Caraway
Food Storage Set
Glass containers with plastic lids
Lower concern; glass + plastic lids with stated PFAS-free position, but no third-party verification of lid material.
⚠Risky category by default
Caraway
Home 9-Piece Mini Food Storage Set
Borosilicate glass containers with plastic lids
Lower-concern option; glass containers avoid PFAS coatings, but verify lid material before purchase.
⚠Risky category by default
Caraway
Cream 6.6-Cup Non-Stick Glass Food Storage Container with Lid
borosilicate glass with non-PFAS lid
Lower PFAS concern, glass container with stated non-PFAS lid, though third-party verification absent.
⚠Risky category by default
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.