Litter box

Litter box (Courtesy eviltomthai on Flickr)

NEW YORK (Reuters) - A New York judge has ordered a cat litter manufacturer to temporarily stop airing "literally false" commercials claiming its product leaves litter pans less smelly than one made by a competitor.

Clorox, a California-based household products company, began running commercials for its Fresh Step cat litter in 2010 that suggested cats, given a choice, preferred to defecate in Fresh Step rather than Arm & Hammer Super Scoop litter.

It agreed to stop broadcasting those commercials after Church & Dwight, which manufactures the Arm & Hammer products, sued.

Then last year, Clorox began airing new commercials that claimed to show that carbon, the main odor-eliminating ingredient in Fresh Step, was more effective than baking soda, the main active ingredient in Super Scoop.

Church & Dwight sued again, and a judge ruled in favor of the Super Scoop lawyers, ordering an immediate ban on the Fresh Step commercial while the case continues.

"Clorox, cloaking itself in the authority of 'a lab test,' made literally false claims going to the heart of one of the main reasons for purchasing cat litter," Judge Jed Rakoff wrote in his ruling on Tuesday.

His 13-page decision focused on a sequence in the Clorox commercials that shows two beakers -- one labeled "carbon" and the other "baking soda" -- filled with green gas representing litter tray odor. The green gas is all but vanquished by the carbon, but continues to swirl largely unaffected by the baking soda.

Clorox, in its testimony, said it had based the sequence on an in-house "jar test" involving 11 people who were trained in grading the unpleasant smells on a scale of 0 to 15 and then made to sniff samples of cat urine and feces that had been combined with carbon, baking soda or nothing at all, sealed in jars and left to sit for about a day.

The judge said the test shed little insight onto the relative merits of the competing cat litter, noting that in practice, "cats do not seal their waste, and smells offend as much during the first 22 hours as they do afterwards."

He also agreed with Church & Dwight's that the runaway odor-eliminating success of carbon in the jar test was dubious.

"It is highly implausible that 11 panelists would stick their noses in jars of excrement and report 44 independent times that they smelled nothing unpleasant," he wrote.

Dan Staublin, a Clorox spokesman, said the company was "disappointed by the court's ruling and stand by the truthfulness of our advertising. We intend to vigorously defend this matter."

Patrick de Maynadier, Church & Dwight's general counsel, said the company was pleased by the judge's ruling. Church & Dwight is seeking an unspecified amount of damages from Clorox for the commercials.