The ZeroWater lawsuit history has two main chapters: a 2010 false advertising case brought by the bottled water industry that settled within months, and a multi-front battle with Clorox’s Brita subsidiary over patents and antitrust claims that ended in August 2025 when both sides walked away from their suits. Two months later, the Federal Circuit invalidated the Brita patent that had started the fight.
ZeroWater’s Antitrust Case Against Clorox and Brita
The larger dispute began in December 2021, when Brita sued Zero Technologies for patent infringement in the District of Delaware, claiming ZeroWater’s gravity-fed filters infringed U.S. Patent No. 8,167,141, “Gravity Flow Filter.”1GovInfo. Zero Technologies LLC v. The Clorox Company, Case 2:22-cv-03989 Brita simultaneously filed a complaint at the U.S. International Trade Commission seeking to block imports of the accused filters.2American University Business Law Review. How Brita’s Alleged Patent Ambush Can Wash Away Competition in the Water Filter Field The Delaware case was stayed pending the ITC investigation.
ZeroWater — by then a Culligan International subsidiary following a March 2020 acquisition — struck back on October 6, 2022, filing an antitrust suit against Clorox and Brita in the Eastern District of Pennsylvania.3Bloomberg Law. Clorox Loses Bid to Toss ZeroWater’s Filter Antitrust Lawsuit The complaint alleged violations of Section 2 of the Sherman Act along with state-law claims for unfair competition, breach of contract, and breach of the covenant of good faith and fair dealing.
The Patent Ambush Allegation
ZeroWater’s central theory was that Brita had run a “patent ambush.” According to the complaint, Brita sat on an NSF Foundation task force starting in 2004 that developed the NSF/ANSI 53 standard for gravity-fed water filters. Adopted in February 2007, that standard became the industry benchmark for certifying filter performance against contaminants like lead, chromium, and PFOA/PFOS.2American University Business Law Review. How Brita’s Alleged Patent Ambush Can Wash Away Competition in the Water Filter Field ZeroWater alleged Brita concealed from the task force that it held or was developing patent rights covering technology essential to meeting the standard. The “Gravity Flow Filter” patent application was filed in September 2008, after the standard was in place.1GovInfo. Zero Technologies LLC v. The Clorox Company, Case 2:22-cv-03989
ZeroWater claimed Brita then waited years, until competitors had invested in NSF/ANSI 53-compliant manufacturing, before asserting its rights. The goal, according to the complaint, was to push rivals out of the high-performance gravity-fed filter market or force them to pay steep licensing fees.1GovInfo. Zero Technologies LLC v. The Clorox Company, Case 2:22-cv-03989 Brita denied any obligation to disclose the patent under NSF rules and said it only learned of ZeroWater’s allegedly infringing products in 2021.
Clorox’s Motion to Dismiss Denied
Clorox and Brita asked the Pennsylvania court to dismiss the antitrust case or transfer it to Delaware. On January 30, 2024, U.S. District Judge Kelley B. Hodge denied both requests in a 50-page opinion.4CourtListener. Zero Technologies LLC v. The Clorox Company, Docket 2:22-cv-03989 She found personal jurisdiction and venue proper under the Clayton Act and declined transfer, noting that moving the case would leave it subject to an indefinite stay tied to the ITC proceeding, which she characterized as “procedural gamesmanship.”1GovInfo. Zero Technologies LLC v. The Clorox Company, Case 2:22-cv-03989
The ITC Ruling and Federal Circuit Affirmance
In September 2023, the ITC issued a final determination in ZeroWater’s favor, finding the asserted claims of Brita’s ‘141 patent invalid.1GovInfo. Zero Technologies LLC v. The Clorox Company, Case 2:22-cv-03989 Brita appealed to the U.S. Court of Appeals for the Federal Circuit.
On October 15, 2025, the Federal Circuit affirmed, holding claims 1 through 6 and claim 23 of the patent invalid for lack of adequate written description and for failing to enable the full scope of the claimed invention.5U.S. Court of Appeals for the Federal Circuit. Brita LP v. International Trade Commission, Case No. 2024-1098 The court found the patent specification disclosed only carbon-block filters as capable of hitting the claimed performance factor, and that the specification itself acknowledged no mixed-media filters had met the standard. Brita could not, the court held, rely on the general knowledge of a skilled artisan to fill the gaps in what the patent actually disclosed.6IPWatchdog. CAFC Affirms ITC Finding Brita Gravity Flow Patent Invalid, Lacking Written Description, Enablement
August 2025 Settlement and Dismissals
The parties resolved everything before the Federal Circuit ruled. On August 4, 2025, a stipulation of dismissal was filed in the Pennsylvania antitrust case. The next day, Judge Richard G. Andrews granted Brita’s request to dismiss its Delaware patent infringement suit with prejudice, meaning Brita cannot refile those same claims against ZeroWater.7Bloomberg Law. Brita and ZeroWater End Water Filter Patent, Antitrust Suits8PatSnap. Brita v. Zero Technologies – Culligan Water Filtration Patent No financial terms were publicly disclosed.
The 2010 IBWA False Advertising Lawsuit
Years earlier, ZeroWater faced a very different kind of case. On March 10, 2010, the International Bottled Water Association sued Zero Water Technologies in the Eastern District of Virginia, accusing the company of making false and misleading claims about bottled water to sell its filters.9IBWA. IBWA Files Lawsuit Against Zero Water for Making False and Misleading Claims About Bottled Water
The complaint targeted several categories of ZeroWater marketing. The IBWA alleged ZeroWater advertised its products as removing “100% of detectable dissolved solids” and implied that the absence of total dissolved solids meant healthier or cleaner water, when TDS is an innocuous mix of minerals and not a meaningful contamination indicator.9IBWA. IBWA Files Lawsuit Against Zero Water for Making False and Misleading Claims About Bottled Water The IBWA also said ZeroWater’s marketing referenced the FDA in ways that implied testing or approval that had not occurred, since home filtration is largely unregulated. And it accused ZeroWater of overstating filter capacity, claiming the carbon filters were quickly exhausted and did not remove all the impurities advertised.10New York Post. Bottled Water Files Lawsuit Against Filtered Water
The case settled within months. On October 4, 2010, the IBWA announced ZeroWater had agreed to a confidential settlement that included a court-enforceable consent order. ZeroWater committed to stop making specified advertising claims about the health, safety, and taste of bottled water relative to its filters.11IBWA. ZeroWater Agrees to Settle False Advertising Lawsuit Brought by the International Bottled Water Association
Neither case produced a class action or a consumer settlement fund, so there is no payout for ZeroWater customers tied to either dispute.