The Fair Trade Commission has warned air-cleaner maker Tornex Inc. about misleading consumers, sources close to the case said Monday.

The fair trade watchdog warned the company that it may have violated the law on truthful advertising by falsely claiming its smoke-control systems will "guarantee clean air."

The devices are not fully equipped to purify cigarette smoke, which contains about 200 types of dangerous substances, including carcinogens, the sources said.