Just to raise a point here, now that someone has mentioned Tarax. Bio in the UK and bio in France, Germany and probably anywhere else is a completely different thing! Bio liquids, sachets, powders etc found in the UK are not the 'green' alternative that they proport to be, in fact they are the complete opposite. They are the most aggresive form of detergent which is why they clean clothes so well. On the other hand 'biologique' French treatments are exactly what they sound like, ie biological, and Tarax and others like it such as Eparcyl are not detergents at all, but bioligically acting additives that are used to maintain the bacterial levels of France's most popular sewage system the 'fosse septique' which is found in the garden of virtually every house out in the French countryside and is truely biological. One sachet per week is all that is needed to keep all those little French microbes in the fosse as happy as a pig in.......whatsit.