Glasslock · Food Storage Containers
Glasslock 18-Piece Assorted Oven Safe Container Set
Lower PFAS concern, glass containers are intrinsically non-fluorinated; seals warrant verification but brand silence is typical.
Glasslock's core product is borosilicate glass, which does not contain PFAS. Polypropylene lid seals carry minimal but unconfirmed risk; the brand makes no PFAS claims and provides no third-party testing. This is a straightforward glass storage set with lower concern relative to nonstick or treated cookware.
Shop Glasslock on Amazon →Material
borosilicate glass lids, polypropylene seals
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
The containers themselves are borosilicate glass, a chemically inert material that does not leach into food across normal temperature ranges and resists thermal shock better than soda-lime glass. The lids combine borosilicate glass tops with polypropylene (PP, #5 plastic) seals. Polypropylene is one of the more thermally stable food-contact plastics and does not contain BPA or commonly used phthalates by design, though the seals will degrade over time with repeated heating and cooling cycles.
The brand's record and disclosure
Glasslock publishes no detailed material safety data sheets or third-party certifications (BPA-free claims, FDA compliance statements, or independent testing results) on their public-facing channels, which is typical for mid-tier food storage brands. No documented recalls, contamination incidents, or safety controversies involving Glasslock containers appear in FDA or CPSC records. The brand's silence on chemical content is common practice rather than a red flag, as borosilicate glass and food-grade PP require minimal disclosure under current US regulations.
How it compares in its category
Glasslock containers are positioned in the mainstream price tier alongside Pyrex and OXO glass storage sets. Compared to plastic-only alternatives (Rubbermaid, Tupperware), the glass body eliminates polymer leaching concerns entirely. Compared to premium glass sets (Pyrex Ultimatum, Anchor), Glasslock offers competitive durability at lower cost, though lid seal longevity may differ. Most competitors in this category use similar PP or silicone seals, so seal replacement costs and intervals are standard across the segment.
If you buy it
Avoid prolonged heating of sealed containers in the microwave; transfer food to a separate dish or use lids off. Hand-wash the seals when possible to extend their lifespan; dishwasher heat degrades PP faster. Replace seals every 2-3 years or if they no longer compress evenly or show visible cracks. Store containers away from direct heat sources and do not use them in conventional ovens (oven-safe label refers to the glass body, not the seals).
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.”
Polypropylene seal degradation over time
PP seals will crack, warp, or lose compressive fit after repeated hot-wash cycles or prolonged microwave exposure. No contamination reported, but degradation reduces seal integrity and may allow food oxidation or mold growth in stored food.
Borosilicate glass thermal shock fracture
While borosilicate is more resistant than common glass, rapid temperature changes (e.g., cold refrigerated container to hot dishwasher or oven) can cause cracking or shattering. Proper cooling before washing reduces risk.
BPA and phthalate leaching from seals
Polypropylene seals in food-grade applications do not typically contain BPA or ortho-phthalates by regulatory design. No testing or recalls for Glasslock seals show contamination, and brand does not use known problematic formulations.
Mold or bacterial growth under seals
If seals are not dried completely or containers stored with lids on in humid conditions, the seal ridges can trap moisture and support mold. This is a user-maintenance issue, not a product defect.
Microplastics from seal wear
No published data on PP seal shedding in Glasslock containers. Theoretical risk exists from any plastic seal under friction, but extent and health relevance for food-contact PP remain unestablished.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 92% 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.