Ziploc · Disposable Food Containers
Ziploc Square Food Storage Container
Lower concern. Polypropylene rarely uses PFAS but brand discloses nothing.
Ziploc Square containers are polypropylene plastic with no known PFAS treatment. Ziploc does not publicly disclose PFAS status, leaving some uncertainty about processing or coatings.
We flunk more products than we pass. This one earned its grade. How we grade
Material
Polypropylene (PP) plastic container and lid
Brand disclosure
Brand is silent on PFAS
Lab data
No public lab test
Why this grade
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
Category baseline
food packaging is a category where PFAS exposure is more common.
No PFAS disclosure
No public statement about PFAS in this product.
The full breakdown
What it's made of and why it matters
Ziploc Square containers are polypropylene (PP), a thermoplastic that does not naturally leach BPA, BPS, or phthalates at room temperature or during normal refrigeration. Polypropylene is microwave-safe up to manufacturer limits because it has a melting point around 130°C, well above typical food storage temperatures. The lid typically uses the same polypropylene or a compatible co-polymer. No formulations of PP are known to release 1,4-dioxane or formaldehyde releasers under normal use.
The brand's record and disclosure
SC Johnson (Ziploc's parent company) has published limited transparency on PFAS use in food-contact plastics, though polypropylene as a base material is not a typical PFAS carrier. Ziploc containers have not been subject to recalls for chemical leaching or contamination in recent public records. The brand is FDA-cleared for food contact and meets BPA-free voluntary standards, but does not publish detailed ingredient or PFAS-testing data. No independent testing has raised red flags for this specific product line.
How it compares in its category
Polypropylene food storage is among the lowest-risk plastic options for cold and room-temperature storage, comparable to glass in chemical safety but more durable. It carries less contamination risk than older polycarbonate containers (which may contain BPA) or PVC/polyvinyl chloride (which can leach phthalates). Ziploc's market-standard manufacturing and FDA compliance place it in the mainstream safety tier for disposable/durable plastic food containers.
If you buy it
Avoid microwave heating above the manufacturer's stated temperature limit (typically 160-180°C / 320-356°F); transfer hot foods to ceramic or glass before storage if concerned. Replace containers every 2-3 years or if lids become cloudy, brittle, or fail to seal, as degraded plastic may compromise food safety through seal failure rather than leaching. Wash by hand or in cool-to-warm dishwasher cycles; high heat cycles may accelerate polymer breakdown. Do not store fatty, acidic, or alcohol-based foods long-term, as these can soften polypropylene over months.
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.”
Microplastics (fragmentation during use)
Repeated heating, microwave use above limits, or physical wear can cause polypropylene to degrade and shed micro-fragments. Risk is low with normal refrigeration but increases if used for hot food or frequent high-temperature washing.
BPA/BPS leaching
Polypropylene does not contain BPA or BPS by formulation. No recalls or independent testing reports indicate contamination from these chemicals in Ziploc PP containers.
Phthalate leaching
Polypropylene is not formulated with phthalate plasticizers. Risk of phthalate migration is not established for this product class or brand.
Off-gassing or odor transfer
New polypropylene containers may release faint chemical odors in the first weeks; airing out before food contact mitigates this. Containers can absorb odors from stored foods (especially garlic, onion, turmeric), which is a usability issue rather than a safety hazard.
Seal degradation and food contamination risk
Consumer reports note that Ziploc lids can become loose or crack over time, compromising airtight sealing and allowing air, moisture, and potential mold ingress. Replacement is the appropriate remedy and occurs within normal product lifespan (2-3 years).
What we don’t know
This grade is a model-based estimate from public materials, coatings, and brand disclosure at 72% 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.
More disposable food 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.