A putative class action claims Colgate-Palmolive’s antibacterial liquid hand soap has a dirty little secret: It’s not a better germ killer than ordinary soap.

The company touts Softsoap Antibacterial as killing 99 percent of germs, even though it is no more effective than products that do not contain an antimicrobial agent, the plaintiffs allege in Donohue v. Colgate Palmolive Co., 11-cv-7026.