According to allegations raised in a recently filed product liability lawsuit, side effects of Zantac caused a Florida man to develop colon cancer, indicating that recent discovery that ranitidine contained in the heartburn drug converts to a cancer-causing chemical will likely go down as one of the “gravest public-health frauds in modern times.”

The complaint (PDF) was filed by Christopher Montgomery in the U.S. District Court for the Southern District of Florida on May 20, claiming the makers of Zantac intentionally hid the fact that users may be exposed to dangerous levels of N-Nitrosodimethylamine (NDMA), a known cancer-causing chemical.

Montgomery indicates that he used Zantac for 11 years before being diagnosed with colon cancer in July 2016, naming the drug makers Sanofi, Sanofi-Aventis, US, Chattem, Boehringer Ingelheim, GlaxoSmithKline and Pfizer as defendants in the lawsuit.

Zantac (ranitidine) has been a top selling heartburn and acid reflux medication for decades, becoming the first medication to surpass $1 billion in annual sales in 1988. However, the drug has now been recalled due to a potential Zantac cancer risk, after it was discovered that the active pharmaceutical ingredient inherently produces high levels of the chemical byproduct NDMA, potentially causing users to develop colon cancer, kidney cancer, testicular cancer, bladder cancer and other injuries.

“Put simply, Zantac is a cancerous poison,” according to the complaint. “When ingested, every tablet (and every dose), produces the toxic carcinogen N-Nitrosodimethylamine (NDMA) in the body. NDMA is a by-product or waste product of various industrial processes, including the manufacture of rocket fuel. NDMA’s lone medical use is toc ause cancer in animals for laboratory experimentation.”

While FDA standards limit the safe exposure to NDMA at 96 nanograms daily, independent testing has found that some 150 mg Zantac pills contained more than 3 million nanograms.

On April 1, the FDA recommended that all versions of Zantac be recalled from the market, since ranitidine in the heartburn drug may produce high levels NDMA when stored at higher than room temperatures and it was impossible for regulators to determine how long and under what conditions the pills were stored.

Since concerns emerged about NDMA contamination late last year, dozens of similar Zantac lawsuits have been filed by individuals throughout the United States, each involving similar allegations that the drug makers knew, or had reason to know that Zantac is a cancerous poison, yet withheld warnings and information from consumers and the medical community, continuing to market the drug as a safe and effective treatment for heartburn and acid reflux.

As Zantac recall lawyers continue to investigate potential claims over the coming months and years, it is widely expected that thousands of lawsuits will be brought throughout the federal court system.