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.

Bleach contains chlorine. If chlorine and ammonia are mixed chlorine gas is given off, which is highly toxic, damaging skin, eyes and other membranes. It is also an irritant, and has been associated with birth defects and cancer. It can trigger asthma attacks and can aggravate respiratory ailments or heart conditions. Chlorine is also responsible for destroying ozone when released into the atmosphere – and concentrations in the air are increasing.

Chlorine is also found in multi-purpose cleaners, washing powders, disinfectants, mould inhibitors, and antibacterial hand washes. Be particularly careful when opening your dishwasher – the hot mist can be full of chlorine, and it is more potent when hot.

Chlorine can form organochlorines and dioxins, which don’t break down easily, and which are highly toxic. Dioxin is the most carcinogenic compound known.