Ziploc bags sat quietly in the safe pile for decades. Then in April 2025 a class action landed on S.C. Johnson alleging the “microwave safe” and freezer labels mislead customers, because polyethylene bags shed microplastics under exactly those conditions. Rubbermaid’s parent company caught a similar suit. So are the bags in your drawer a problem?
What the Lawsuits Claim
The California suit argues that labeling polyethylene bags “microwave safe” and “suitable for freezer use” misleads consumers, because heating and freezing cause the material to release microplastic particles into food, making the products, in the lawsuit’s words, unfit for the uses on the label. Named products include freezer bags, slider bags, and storage containers. These are allegations, not findings; the cases are working through the courts. But the underlying question is a fair one.
What the Science Says
The heat half of the claim stands on the firmer ground. Studies of plastic food containers consistently show that microwaving accelerates particle release, by large multiples compared to room-temperature storage. Freezing is more debated, with some research suggesting temperature swings stress the material. For ordinary room-temperature storage, polyethylene remains regarded as one of the more inert food plastics. The pattern across the research is simple: plastic plus heat is the combination to avoid.
The Sensible Rules
You do not need to wait for a verdict to act on what is already known. Never microwave food in any plastic, bag or container, regardless of the label. Move hot leftovers to glass before storing. Treat single-use bags as what they are, room-temperature and short-term carriers, and retire scratched or cloudy plastic containers, since damaged surfaces shed more. Those four habits remove most of the realistic exposure without a single purchase.
The Swap
If the lawsuits are the push you needed, the replacements are better products anyway. Stasher bags are platinum silicone, stable from freezer to microwave to oven, and we put them through a full review in our Stasher deep-dive. Glass containers handle reheating without any material question. The complete field, including beeswax wraps for the things bags were never right for, is ranked in our reusable food storage guide.
Frequently Asked Questions
Can you microwave Ziploc bags?
The label says microwave-safe for defrosting and reheating; the 2025 lawsuit disputes exactly that claim. Our advice is simpler: don’t microwave food in any plastic. Transfer to glass or ceramic first; it takes ten seconds.
Are Ziploc bags BPA-free?
Yes. Ziploc bags are polyethylene, which doesn’t contain BPA. The current concern is different: physical microplastic particles shedding from the material under heat and stress, which BPA-free labeling says nothing about.
What can I use instead of Ziploc bags?
Platinum silicone bags (Stasher is the standard), glass containers for anything hot, and beeswax wraps for produce, cheese, and bread. Our food storage guide compares all three.
Did Ziploc lose the microplastics lawsuit?
No verdict either way as of this writing; the suits filed in 2025 are still in progress. The practical takeaways don’t depend on the outcome: keep plastic away from heat and you’ve addressed the core concern.
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