Ziploc · Food Storage Containers
Ziploc Twist 'n Loc Food Storage Containers Variety Pack 8ct
Lower concern, standard rigid PP food containers rarely contain intentional PFAS, but Ziploc provides no public PFAS commitment.
Ziploc Twist 'n Loc containers are rigid polypropylene food storage boxes with snap-lock lids, a material class not typically formulated with PFAS. Ziploc's parent company (S.C. Johnson) has not made a public PFAS-free pledge for this product line.
Shop Ziploc on Amazon →Material
polypropylene (PP) rigid plastic containers and lids
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.
Safe base material
Made from a material with no inherent PFAS use (ceramic, mineral, or natural fiber).
The full breakdown
What it's made of and why it matters
Ziploc Twist 'n Loc containers are rigid polypropylene (PP, plastic #5), one of the safer food-contact plastics for cold and room-temperature storage. Polypropylene does not contain BPA, phthalates, or intentional PFAS in standard formulations. The snap lids and twist-lock mechanism are also PP-based. PP is microwave-safe at manufacturer-stated wattages and temperatures, but prolonged or repeated exposure to heat can degrade the plastic over time, potentially releasing oligomers (small plastic fragments) rather than hazardous monomers.
The brand's record and disclosure
Ziploc (SC Johnson subsidiary) has not published a detailed PFAS commitment or third-party testing data for this product line. The brand does not promote BPA-free status explicitly for rigid containers, though PP inherently lacks BPA. No major safety recalls or contamination incidents are on record for this specific product. The company's general transparency on food-contact material safety is minimal compared to premium alternatives, but this reflects industry norm rather than unusual concern.
How it compares in its category
Ziploc rigid containers are mainstream budget options; they occupy the middle ground between ultra-cheap single-use takeout containers and premium brands (Rubbermaid Brilliance, Pyrex glass) that emphasize durability and explicit material certifications. Polypropylene is chemically equivalent across brands, so safety differences are negligible; durability and lid seal longevity vary more noticeably. The Twist 'n Loc locking mechanism is a design feature aimed at convenience rather than safety, though it may reduce accidental spills of stored food.
If you buy it
Avoid prolonged microwave heating above 170°C (338°F) and do not use for extended hot food storage; PP softens at higher temperatures. Hand-wash lids if possible to extend hinge and seal life; dishwasher heat can degrade snap mechanisms over 50+ cycles. Replace containers if lids no longer seal tightly or plastic becomes visibly cloudy or cracked, as degraded polymers may shed fragments. Store away from direct sunlight and heat sources to slow embrittlement; most PP food containers last 2-3 years with typical home use before practical failure.
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.”
BPA / BPS
Polypropylene formulations do not contain BPA or its substitute BPS as a matter of material chemistry; this hazard is not applicable to PP rigid containers.
Phthalates
PP rigid food containers do not use phthalate plasticizers in standard formulations; phthalates are associated with flexible PVC and some soft plastics, not PP.
Microplastics from degradation
Repeated heating cycles, prolonged microwave use, or physical wear can cause PP to degrade and release small plastic particles into food over extended storage. Risk increases if containers are used beyond their practical lifespan or for hot foods above manufacturer temperature guidelines.
Polymer oligomers and off-gassing
PP can release low-molecular-weight oligomers, especially when heated or exposed to fatty/acidic foods; these are generally recognized as low-toxicity but are a known minor exposure pathway from plastic food contact articles.
Coating or lid assembly hazards
Ziploc does not use glazes, enamels, or metal fasteners in these containers that would introduce lead, cadmium, or heavy metals. Hinge and snap mechanisms are plastic-on-plastic and pose no material safety concern at manufacture.
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.
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.