London (CNN)Wet wipes marketed as "flushable" are to blame for 80% of blockages in Britain's sewers, a BBC investigation found.
Insiders interviewed by the broadcaster said the flushable versions of the moist cloths -- which are used for everything from toilet training to household cleaning -- are responsible for the extensive blockages, which cost millions of pounds to rectify.
An investigation by BBC Radio 4's "Costing the Earth" described the ongoing problem as an "environmental menace." In the radio program, host Tom Heap went out with the teams responsible for unblocking drains -- and found that the culprits are usually wet wipes.
While flushable wet wipes will disappear around the U-bend of the toilet, most then go on to join up with "fatbergs" that have to be broken down -- ultimately leading to the recovered wipes being disposed of in landfills.
"Despite what the label says, these wipes definitely shouldn't be flushed down the toilet," Natalie Fee, founder of campaign organization City to Sea, told the BBC.
Fatbergs form over time as items such as wet wipes, diapers, condoms, sanitary products and various types of greases and oils are flushed or washed down drains instead of being disposed correctly.
Thames Water, which operates the water system in London, says it spends £1 million a month, or nearly $1.4 million, to clear blockages of this kind. To reduce their occurrence, it has started a campaign called "Bin it -- don't block it" to educate the public on which items should be discarded as regular garbage rather than flushed down the toilet.
Wipes that are not filtered out can cause even more of a problem, going on to damage the environment. They take years to break down and often contain plastic, which is harmful to the environment.
WRC, a water-testing laboratory in Swindon, revealed that many of the wipes deemed to be flushable do not actually disintegrate as they pass into sewers. None of the flushable wipes marketed as "flushable" in the UK actually passed their rigorous testing.
"Manufacturers clearly know this is a problem. We need to start seeing them change what they say [on the packaging]. It can be confusing for consumers," Fee told the BBC.
A spokesman for Water UK, which represents the major water and wastewater service providers in Britain, said: "There are approximately 300,000 sewer blockages every year, costing the country £100 million -- money which could be taken off bills or spent on improving services.
"There are things that we can do, such as improve education about what should and shouldn't be flushed. There are things manufacturers can do, such as make labeling clearer on non-flushable products. And, of course, there are things individuals can do -- which is bin the wipes rather than flush them."