Stasher · Food Storage Containers
Stasher Storage Bag 4-Pack
Lower concern, third-party verified silicone bags with no PFAS detected.
Stasher bags are made from platinum-grade silicone and carry MADE SAFE certification, which includes independent testing for PFAS. The brand discloses PFAS testing results and makes explicit PFAS-free claims backed by third-party verification. No PFAS-legacy coatings (Teflon-type coating, Teflon-family coating) are used in this product.
Brand says: “PFAS-free; third-party tested by independent labs”
Material
Silicone (platinum-grade)
Brand disclosure
Third-party verified PFAS-free
Lab data
No PFAS found in testing
Why this grade
Waterproof / stain-resistant treatment
water-repellent coating treatments have historically used PFAS.
Category baseline
food packaging is a category where PFAS exposure is more common.
Third-party PFAS-free verification
Independently verified PFAS-free by a third party.
No PFAS found in lab test
No PFAS detected in independent testing.
The full breakdown
What it's made of and why it matters
Stasher bags are made from platinum-cure silicone, a polymer that does not contain BPA, BPS, or phthalates by design. Platinum-cure processing (versus peroxide-cure) is the higher-purity standard and leaves fewer reactive residues in the final material. Unlike plastic containers, silicone has minimal leaching risk across normal temperature ranges because its polymer chains are very stable and not prone to breaking down into small molecules that migrate into food.
The brand's record and disclosure
Stasher has pursued third-party PFAS testing and published results showing no detectable PFAS in their bags, which is notable transparency for a brand in this category. The company markets the product explicitly as PFAS-free and has not faced significant recalls or safety controversies on record. Their material sourcing and manufacturing practices are typical of premium silicone brands that emphasize food-grade certification.
How it compares in its category
Versus conventional plastic containers (which carry BPA or phthalate migration risk, especially when heated), Stasher bags eliminate those hazards entirely. Compared to glass storage, silicone offers durability and convenience without leaching risk at any temperature. Versus other reusable silicone bags, Stasher's platinum-grade material and transparency on PFAS testing place it in the upper tier of the market.
If you buy it
Silicone bags tolerate heat up to approximately 400 degrees Fahrenheit, though regular use at extreme temperatures is not recommended. Hand-wash in warm soapy water or top-rack dishwasher; some users report minor odor absorption over time, which does not indicate degradation. Store in a cool, dry place away from direct sunlight. Replace if you notice visible cracks, permanent staining, or loss of seal integrity, though these bags typically last several years with normal use.
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.”
Silicone leaching / degradation
Platinum-grade silicone is chemically inert across normal food storage and mild heating conditions. No peer-reviewed studies or recall reports document migration of silicone oligomers or other components into food from intact Stasher bags.
BPA / BPS / phthalates
Silicone does not use these plasticizers in its formulation, so exposure from this product is not a concern by material class.
Microplastics generation
Silicone is technically not a plastic, but mechanical wear (friction, folding, or washing) could theoretically shed microscopic silicone particles. No studies specific to Stasher bags quantify this risk; it remains theoretical and likely minimal compared to plastic degradation.
Odor absorption and flavor transfer
Silicone bags are known to absorb strong odors (garlic, curry, fish) that may persist or transfer subtly to subsequent foods. This is a sensory rather than toxicological hazard but worth noting for user experience.
Seal failure and food safety
If the seal mechanism degrades, the bag may no longer be airtight, compromising food freshness and potentially enabling bacterial growth. Regular inspection and timely replacement mitigate this risk.
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.
Formulations and coatings change between production runs. Always check the current label before buying.
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.