Plughole blockages are a breeding ground for bacteria, and can develop poisonous pathogens, including the the lethal E.coli and salmonella bacteria.
The bacteria can become airborne, and spread into the surrounding areas of the home, warned scientists at the University of East Anglia.
They can survive at room temperature on stainless steel for up to 28 days, increasing the risk of infection.
About a third of all sponges could be contaminated with E.coli too, research has revealed.
Food and hair that gets put down plugholes can form blockages, and lead to microbial biofilms. A biofilm is a thin layer of microorganisms that stick together, and grow on moist surfaces.
“Food prepared in the kitchen may be deposited down the sink, introducing potentially pathogenic bacteria to established biofilms or giving them the opportunity to develop one,” the researcher said.
“Plugholes and drains, in both the domestic household and hospitals, pose potential health consequences and could promote the spread of diseases.
“Once bacteria spread to the nearby surroundings they can survive and be spread to further areas.”
Domestic sink drains are also hotspots for the fungi Fusarium solani, which can cause infections and an inflamed eye.
E.coli symptoms include fever, vomiting, watery diarrhoea, and bloody urine. It can lead to kidney failure, and even death.
Salmonella, meanwhile, can cause bloody stools, stomach cramps and vomiting. Dehydration form the condition can be life-threatening.
Every year, the kitchen sink is used to deposit about 1.8 million tonnes of food and drink waste.
You can remove deadly biofilms by removing the physical blockage.
Blockages are usually caused hair, soap sludge, bath oils, toothpaste and dirt.
Buster Bathroom Plughole Unblocked could remove the blockages, it claims.
The manufacturer’s spokesperson Edel Schultz said: “These types of bathroom blockages are of course part of the status quo in a busy household, and nothing to worry about in the short term. But, when you start to experience slow running water or have a blockage, treat it with Buster.
“Prevention is much better than cure when it comes to biofilms and blockages.”