Stasher · Food Storage Containers
Stasher Stand-Up Mega Bag
Lower-concern choice; silicone-based bag with explicit PFAS-free claim and third-party certification.
Stasher's Mega Bag is made from platinum-grade silicone and carries a public PFAS-free commitment backed by MADE SAFE certification. Silicone is an inherently lower-risk material for food contact and does not require waterproofing treatments that typically introduce PFAS.
Brand says: “PFAS-free; made from platinum-grade silicone without added PFOA, PTFE, or BPA”
Material
silicone (platinum-grade silicone)
Brand disclosure
Brand claims PFAS-free
Lab data
No public lab test
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.
The full breakdown
What it's made of and why it matters
This bag is made from platinum-grade silicone, a food-safe elastomer that does not contain BPA, BPS, or phthalates by chemistry. Platinum-grade silicone is produced using a different catalyst system than medical-grade silicone and is widely used in food storage without the softener additives that plague some plastics. The material is non-porous, flexible, and reusable across hundreds of freeze-thaw cycles without known leaching or microplastic shedding.
The brand's record and disclosure
Stasher explicitly markets PFAS-free formulation and has obtained third-party certification (typically NSF or similar standards bodies confirm this claim). The company's transparency on material sourcing and testing is above industry average for reusable food storage. No major recalls or safety controversies related to leaching or coating failure have been documented for this product line.
How it compares in its category
Compared to single-use plastic bags (polyethylene, polypropylene) which degrade and shed microplastics under heat and mechanical stress, silicone bags are chemically inert and designed for repeated use. Compared to glass containers, silicone offers flexibility and drop resistance but lacks the thermal visibility of glass. Compared to other silicone storage products, Stasher's platinum-grade formulation and third-party certification place it among the safer mid-range options in the reusable segment.
If you buy it
Keep the bag below 400°F (204°C) in ovens and away from direct flame; while silicone is heat-stable to higher temperatures, the seal mechanism may weaken with repeated high-heat exposure. Wash by hand or on the top rack of dishwashers; abrasive scouring can degrade the surface over years of use. Replace if you notice permanent discoloration, staining that doesn't wash out, or loss of seal integrity, which typically occurs after 5-10 years of regular use. Store in a cool, dark place away from strong solvents or essential oils, which can cause swelling of the material.
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 under extreme heat
Platinum-grade silicone is chemically stable and does not leach oligomers or additives under normal food storage conditions (room temperature, refrigerator, freezer). High-temperature exposure above manufacturer limits (typically 400°F) is not recommended, but no documented cases of leaching from this product at proper use temperatures exist.
Microplastic shedding
Silicone bags do not shed microplastics as they degrade, unlike polyethylene or polypropylene films. The solid, crosslinked silicone matrix remains intact through hundreds of use cycles without fragmenting or releasing particles into food.
Seal degradation and microbial contamination
Repeated opening, closing, and washing can gradually wear the seal mechanism over years of use. A compromised seal allows air entry and moisture loss, potentially creating conditions for mold growth if the bag is stored damp. This is a maintenance and user-care issue, not a manufacturing defect.
Odor and stain absorption
Silicone can absorb and retain strong food odors and pigments (particularly from acidic foods like tomato sauce or turmeric) over extended use. While this is cosmetic and does not indicate chemical leaching into food, permanent discoloration may signal material fatigue and warrant replacement.
BPA/BPS and phthalate contamination (manufacturing origin)
Platinum-grade silicone does not contain these compounds by formulation, and Stasher's third-party certification confirms absence of BPA and BPS in finished product. No recalls or test results show contamination from manufacturing or cross-contamination.
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 85% 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.
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.