Bleach acts by sterilising organic matter through oxidisation. When you chuck bleach down your toilet it not only kills bacteria in your loo (which is why you do it), but it continues to do this right down the sewage chain, killing bacteria which help break down sewage in processing plants. Eco-friendly alternatives use acids which dislodge the dirt, rather than oxidising it.

Borax is a naturally found mineral that has been used as a cleaner for many years, and is therefore considered safe. It is an antibacterial, fungicidal and bleaching agent. It can be used for a wide range of cleaning jobs including the kitchen, clothing and carpets, and in soaps. It can be bought from hardware shops and chemists, or you can get it on-line.