Most of us have our go-to setting on the washing machine dial. Even though there are umpteen programmes, 5 temperatures and 3 speed settings, how many of us just cram in the clothes and set to fast wash for half an hour?
Does it really matter what temperature the water is or what you use to wash your clothes? And has it got implications for health?
Take note of the temperature
Symbols on clothing tags and fabrics will give you the best indication of what temperature to wash them at.
In general terms, the hotter the water the cleaner the clothes will be. Hot washes are good for linens and cottons like sheets and towels and whites.
Everyday clothes don't usually need a hot wash, which could make them shrink or become mis-shapen.
Soiled clothes like cloth nappies and healthcare workers' uniforms will benefit from a hot wash at least 60C with an oxygen bleach-containing product to make sure all of the germs are killed.
Advice from the International Scientific Forum on Home Hygiene (IFH) is that items which come into close and persistent contact with the body, like underwear, socks, towels and bed linens, should be washed at 30-40C with an oxygen bleach-based laundry product.
Wash items differently
The IFH considers it satisfactory to wash outer garments like jackets, skirts and trousers at 30C with any formulated detergent.
"Modern washing powders and detergents have been formulated to get clothes visibly clean at low temperatures, but what we find is that they do not necessarily get clothes hygienically clean as you cannot see residual germs," says Professor Sally Bloomfield, chair of the Home Hygiene Forum.
"That's why IFH recommend that if clothes and linens which come in close contact with the body are washed at 30-40C this should be done with an active oxygen bleach powder which boosts [the] hygiene effect during laundering," adds Professor Bloomfield.
A general rule of thumb is powders and tablets have bleach, gels and liquids don't.
Advice from the Forum is, for the clothes, bedding and towels of someone with an infection, or for soiled clothes like nappies and sports gear as well as cloths and tea towels, wash at 60C or more using an oxygen-bleach-based laundry product.
You shouldn't mix these items with everyday clothes either, so don't put tea towels in with normal clothes.