Ziploc Lawsuit: Are "Microwave Safe" Bags Leaking Microplastics?

Case Overview: A class action lawsuit claims Ziploc bags, marketed as “microwave safe” and “freezer safe,” may release microplastics when heated or frozen, posing potential health risks to consumers.

Consumers Affected: Consumers who purchased Ziploc bags based on "microwave safe" or "freezer safe" claims.

Court: U.S. District Court for the Northern District of California, San Francisco Division

S.C. Johnson & Son, the maker of Ziploc, falsely markets its bags as “microwave safe” and “suitable for freezer use,” a new class action lawsuit alleges. 

The lawsuit claims that these assurances mislead consumers and hide the potential health risks of microplastic exposure when the bags are heated or frozen.

Ziploc Bags Accused of Releasing Microplastics

Linda Cheslow filed the lawsuit on April 25 in California federal court, saying she relied on the product’s claims when buying Ziploc bags earlier this year. Like many health-conscious shoppers, Cheslow says she tries to avoid microplastics in her food, but trusted the brand’s assurances.

According to the complaint, Ziploc bags are made from polyethylene and polypropylene—plastics that, when heated or frozen, may release microplastics. Cheslow argues this makes the products “fundamentally unfit” for the uses they’re marketed for.

“As a result,” the complaint reads, “consumers have unwittingly exposed themselves and their families to undisclosed microplastics during routine kitchen practices.”

Consumers Say They Were Unaware of Potential Health Hazards

Microplastics are tiny plastic particles less than 5mm wide, typically created when larger plastics break down. Scientists are still studying their health effects, but research has linked microplastics to hormone disruption, reproductive issues, and increased cancer risks.

The lawsuit says that labeling Ziploc bags as microwave or freezer safe without warning of potential microplastic leaching is a "material omission" that could mislead even cautious consumers. 

Cheslow argues that a company with Ziploc’s reach has a responsibility to be upfront about possible health concerns, especially as public awareness of microplastics grows.

Other Companies Face Lawsuits Over Harmful Chemicals in Products

This isn’t S.C. Johnson’s first legal challenge over its packaging claims. A separate pending class action in Illinois says Ziploc’s promises of “unbeatable protection” and “freshness” are also misleading. That lawsuit says the company’s lab tests don't reflect real-world use and fail to account for other ways food can spoil beyond just moisture loss.

Ziploc isn’t the only brand under fire for allegedly exposing consumers to harmful substances. Toymaker ZURU is facing a proposed class action over claims its Bunch O Balloons were falsely advertised as eco-friendly despite containing PFAS, or “forever chemicals.” 

Similar lawsuits have been filed against the makers of Gore-Tex and Apple Watch bands, accusing both companies of promoting their products as safe or sustainable while knowingly using PFAS.

In this latest case, Cheslow is seeking class action status, including a California subclass. The lawsuit aims to secure damages, restitution, an injunction against further misleading labeling, and potentially punitive penalties.

Case Details

• Lawsuit: Cheslow v. S.C. Johnson & Son, Inc.
• Case Number: 3:25-cv-03655 
• Court: U.S. District Court for the Northern District of California, San Francisco Division

Plaintiffs' Attorneys

• Ryan J. Clarkson, Bahara Sodaify, and Alan Gudino (Clarkson Law Firm, P.C.)

Do you use Ziploc bags for heating or freezing food? Share your thoughts on these allegations below.