Consumer New Zealand is sounding a warning about anti-bacterial soaps, saying they could actually do more harm than good by building bacterial resistance to antibiotics.
Chief executive Sue Chetwin says the soaps are little more than a marketing invention that plays on people's fear of germs.
She says the Food and Drug Administration in the United States is looking at ways of making manufacturers prove their products work and are safe for everyday use, and New Zealand should follow suit.
"We think that plain soap and water if you want to wash your hands is just as good, if not better, than any of the so-called anti-bacteria soaps and we're very concerned that they are doing us harm by reducing the effectiveness of drugs that we rely on to fight these infections when we do get sick."
Ms Chetwin also says the chemicals in antibacterial soaps have been found in wastewater, and studies are being done in New Zealand to investigate the environmental effects.