Stasher · Food Storage Containers
Stasher Mega Stand-Up Bag
Lower-concern reusable food bag; brand explicitly avoids PFAS and holds third-party certification.
Stasher Mega bags are made from food-grade silicone and marketed as PFOA/Teflon-type coating-free. The brand holds MADE SAFE certification, a third-party standard that tests for PFAS. No public lab data shows PFAS detection; silicone itself does not require water-repellent coatings that commonly introduce PFAS.
Brand says: “Made without PFOA or PTFE. We use food-grade silicone that is free from harmful forever chemicals.”
Material
silicone (food-grade, Teflon-type coating-free)
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
Stasher Mega bags are made from platinum-cure food-grade silicone, a non-porous polymer that does not contain BPA, BPS, phthalates, or Teflon-type coating (Teflon). Silicone does not leach harmful chemicals when heated or in contact with acidic foods, fats, or oils. The material is inert, meaning it resists degradation and does not break down into microplastics under normal use. This makes it chemically stable across the temperature range of refrigeration, freezer, and oven/microwave exposure.
The brand's record and disclosure
Stasher explicitly markets these bags as PFAS-free and holds third-party certification (NSF certification claimed for food contact compliance). The brand has maintained this stance publicly without documented recalls or safety violations related to leaching or contamination. Stasher provides straightforward material information on product pages and packaging, listing food-grade silicone as the sole container material.
How it compares in its category
Silicone food bags outperform most plastic food-storage alternatives (PET, polypropylene, polycarbonate) because they avoid the leaching risks associated with plasticizers and hardening agents. Compared to glass storage, silicone offers lighter weight and break resistance; compared to stainless steel, it is more flexible and transparent for content visibility. Reusable silicone bags are positioned as a durable, low-waste alternative to single-use plastic bags and disposable containers.
If you buy it
Hand-wash or place on top rack of dishwasher; avoid scouring pads that can scratch the surface. Safe for freezer to microwave (check manufacturer's stated temperature limits, typically minus 40 to 400 degrees Fahrenheit). Inspect quarterly for discoloration, odor retention, or visible degradation; replace if the seal weakens or material becomes sticky or cloudy. Store in a cool, dry place away from direct sunlight to extend the life of the silicone.
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.”
Microplastic shedding
Silicone does not fragment into microplastics under normal use conditions (heating, freezing, or aging). No documented incidents of silicone food bags releasing microparticles into food.
BPA/BPS leaching
Food-grade silicone is not synthesized using BPA or BPS as starting materials or plasticizers. These hazards are not present in the formulation of this product.
Phthalate migration
Silicone does not use phthalate plasticizers for flexibility. This hazard class is not relevant to platinum-cure silicone food bags.
Thermal degradation and off-gassing
Silicone is stable under normal cooking and microwave use. However, prolonged exposure to extreme heat (above manufacturer specifications) or direct flame may theoretically accelerate polymer breakdown. No documented incidents in consumer use at recommended temperatures.
Odor retention and leachate from stored foods
Silicone can absorb and retain strong odors and flavors from foods (especially oils and spices), but this is a material property unrelated to chemical hazard. Some users report persistent odor even after washing; this does not indicate contamination or leaching of bag material into food.
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.
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.