It’s a germ-filled world out there: swine flu and bird flu, Sars, MRSA, not to mention a host of other superbugs that threaten our health. So it’s little wonder that we are increasingly obsessed with products that promise to fight germs with sterility. Top of the list on our antimicrobial crusade are hand washes and sanitisers, sales of which have soared by up to 80% in the past two years and, according to the Cosmetic Toiletry & Perfumery Association, are part of a market worth £119m in 2008. If you carry your handbag-sized bottle of chemicals designed to kill any germs that cling to the skin, then, the theory goes, you can stroll carefree through the microbial battlefield of daily life. But experts in the field argue that they could provide a false sense of security.

Available as products used with water, or as gels rubbed directly onto the hands, most of these cleansers contain alcohol and other powerful antibacterial chemicals such as triclosan or benzalkonium chloride, substances that will destroy bugs. They work by stripping away the outer layer of oil on the skin. For many, they have become indispensible. They have also helped to fuel a paranoia about personal cleanliness that has been dubbed HSOCD (hand sanitizer obsessive compulsive disorder). The symptoms are clear: a fear of contact with anything — from door knobs to hand rails on the Tube — that may have been touched by someone else, and the prompt use of a hand sanitiser to eradicate germs.

Celebrities are frequently spotted applying antibacterial hand gels, while more extreme germophobes such as the property tycoon Donald Trump refuse to touch the ground-floor button of a lift and avoid shaking hands with people. Products such as Frais, a natural alternative that contains gentler sugar-cane alcohol, are becoming cult accessories for the eco-conscious. One woman I know applies a sanitising gel to the hands of her young son whenever he plays with toys that aren’t his. Countless others will not touch light switches or computer keyboards without first wiping the object, then scrubbing their hands.

But are sanitisers really the answer in the fight against germs and disease? Most experts think not. Dr Anthony Hilton, a microbiologist at Aston University, says: “The antimicrobial component of these products has become a psychological safety net for people who have become alarmed by high-profile viruses.” He says there is no evidence that they offer “significant additional protection” . Studies have shown that while antibacterial products may initially remove more harmful organisms than soap and water, within 90 minutes there is no difference in the number of bacteria on your hands. “In everyday life, people do not need antibacterial sanitisers,” says Dr Derren Ready, a microbiologist at University College London. “Old-fashioned soap and water is fine.”

Their opinions are backed by evidence from a 2007 study that found antibacterial cleansers to be no more effective than soap and water at removing bacteria from the hands. Professor Allison Aiello, an epidemiologist at the University of Michigan School of Public Health, also showed that people who used sanitising hand products on a daily basis suffered just as many bouts of cold, flu and stomach problems as those who used soap and water. Professor Stuart Levy, a microbiologist at Tufts University in Boston, agrees. “Illnesses such as the common cold are not caused by bacteria, but by viruses,” he says. “Antibacterial products won’t destroy a virus.”

Hand sanitisers might even do more harm than good. Aiello found that triclosan caused some bacteria to become resistant to commonly used antibiotics. Scientists are also worried about the indiscriminate killing of germs by hand sanitisers. Antimicrobial washes kill both harmful and helpful bacteria, adding weight to the argument that we can be too clean. Many experts believe that the overuse of cleaning products dulls the immune system to the point that it no longer knows how to fight bacteria, and that increasingly sterile environments have led to a rise in allergies such as asthma, eczema and hayfever.

However, while the popularity of antibacterial hand cleansers remains controversial, all bug experts agree on one thing: washing your hands well is a vital step towards fighting disease. “Viruses can survive on human hands for several hours and may be spread by direct contact,” says Professor John Oxford of the Royal London Hospital. Given that we can touch up to 300 surfaces in half an hour, a person may easily pick up infections on their fingers by touching an infected object. “People would be better off paying attention to how they wash their hands, not what they wash them with,” says Ready. “It is important to wash the whole of the hand — not just the thumbs as many people do — and vital to dry them thoroughly as bacteria need moisture and warmth to thrive, but soap and water will do.”

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