Ask G

Ask us: Anti-bacterial products

Tanya Ha gives some topical advice given that it’s peak cold and flu season.

Are anti-bacterial products are environmentally friendly? I particularly want to know now that we’re heading into the cold and flu season.

- Cat Johnson


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Antibacterial products are intended to kill bacteria. But it’s viruses that cause the vast majority of colds and flu cases. Viruses and bacteria are very different. Bacteria are living, cellular microorganisms that happily multiply in warm, moist conditions. In contrast, viruses are basically little packets of genetic material that need the machinery of an invaded host cell to reproduce. Bacteria and viruses are part of healthy ecosystems. For example, we need ‘good’ gut bacteria to help digest food. It’s the illness-causing bacteria and viruses – or ‘pathogens’ – that we want to avoid in order to stay well.

Antibacterial agents are in everything from cleaning products, garbage bags, hand lotions to carpet underlay and even toothpaste. Antibacterial products are ineffective on viruses, including influenza and rhinoviruses (the common cold culprit). They serve a purpose in hospital and healthcare settings when used properly, but in homes they are no more effective at keeping bacteria numbers down than soap, plain detergents and warm water. In short, they add to the cost for no real benefit. Meanwhile, some scientists believe our ‘too clean’ homes are depriving our immune systems of the small battles against pathogens needed to build strong immunity.

Sir William Osler, the ‘father of modern medicine’, put it well when he said, “Soap, water and common sense are the best disinfectants.” Good hygiene is the first line of defence against illness-causing bacteria and viruses. To prevent the spread of colds and other contagious illnesses always wash and dry hands thoroughly with soap before handling food or eating, and after blowing your nose, handling money or going to the toilet.

On a more ecological perspective, antibacterial agents can kill non-target beneficial bacteria. For example, soil microbes in your garden won’t like greywater containing antibacterial laundry detergent or bleach. There is some concern antibacterial agents, like triclosan, may enter the environment and bioaccummulate in the food chain. However, because their widespread use is relatively recent, more research is needed.

Scientists and health authorities are concerned the widespread use of antibacterial agents and antibiotics could be contributing to the development of antibiotic resistant bacteria or ‘superbugs’, against which we are defenceless. The misuse of antibiotic drugs is the greater problem. How much antibacterial cleaning products contribute to this problem is not yet known, but it has been demonstrated in the lab and more long-term research is needed in ‘real world’ conditions.

Tanya Ha is an expert environmentalist and author. To ask a question for her next column, email