A German firm disputes claims that Tennant's "active water" cleans effectively.
A German competitor of Tennant Co. has sued the Golden Valley-based manufacturer of floor scrubbing machines, saying it makes false and misleading claims for its chemical-free cleaning technology.
In suits filed in Germany, Belgium and the United Kingdom, Alfred Kärcher GmbH & Co. KG disputed advertising claims by Tennant that scrubbers using its ec-H2O technology electronically convert tap water into "active water" that's as effective as a powerful cleaning agent.
The company said in a news release that Tennant's claims were investigated and refuted by an independent research institute that it did not identify.
"[Tennant] is thereby trying in a highly unfair manner to set itself apart from the competition -- and making a promise to customers that it cannot possibly fulfill," the Kärcher release said.
Tennant spokeswoman Kathryn Lovik said in a statement that the company rejected Kärcher's assertions and that Tennant's claims were supported by its own third-party, independent test results.
Representatives of Kärcher, a cleaning equipment giant that does business in 50 countries including the United States, could not be reached for comment Wednesday.
Tennant's ec-H2O technology has been a growth engine for the company since it was introduced in 2008. Sales of scrubbers equipped with the technology have grown from just $17 million, or 2 percent of total sales in 2008, to $96 million, or 14 percent of total sales last year.
In 2010, Tennant established Orbio Technologies, a separate group for its chemical-free cleaning products.
The suit isn't the first time a competitor has publicly questioned Tennant's claims for its chemical-free cleaning technology. Last year, Nilfisk-Advance, a Danish manufacturer of floor cleaning equipment with U.S. operations in Plymouth, announced results of independent tests that it said showed a scrubber using Tennant's technology did not perform better than the same scrubber using ordinary tap water.
Tennant said the tests were misleading and stood by its claims.
Lovik said the company can point to many satisfied customers. "They have purchased -- and continue to purchase -- Tennant machines equipped with ec-H2O technology based on their own experiences with its performance."
However, Tennant also told Nilfisk this year that it had discontinued one claim that ec-H2O makes water perform like a "powerful detergent," said Stacy Bettison, a Nilfisk spokeswoman.
Susan Feyder • 612-673-1723