Many cleaning products say they kill 99.9 per cent of germs. Should I worry about the remaining 0.1 per cent?

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We don’t use products killing 99.9 per cent of germs on our plates and get along just fine so soap and a decent clean should be enough to sort any germs.

In most cases, you don’t even need to worry about the 99.9 per cent. On hard surfaces, soap or detergent will remove enough germs for your immune system to cope with the few that sneak past. That’s a strategy we’re quite happy to adopt for the plates we eat off, so why should we need anything stronger for the kitchen floor?


The 99.9 per cent figure is a fairly meaningless claim used by advertisers. Although it may be backed up by scientific tests, it doesn’t tell us which strains of bacteria and viruses are killed, nor anything about the thoroughness of the cleaning procedure used in the original tests.

Most bacteria are harmless to a healthy person in the quantities that we encounter on typical surfaces. And if you do need more antiseptic conditions, the thoroughness of your cleaning is more important than the ‘kill percentage’ on the bottle.

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luis villazon
Luis VillazonQ&A expert

Luis trained as a zoologist, but now works as a science and technology educator. In his spare time he builds 3D-printed robots, in the hope that he will be spared when the revolution inevitably comes.


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