Recently, there was a message circulating in the WeChat circle of friends: "Please do not put blue toilet blocks in the water tank of your own toilet." Toilet blocks are only suitable for foreign buildings with dual water supply systems, and there are almost no such water supply systems in China. Since the main valve and the sub-valve do not have a one-way check valve, under the action of negative pressure, the polluted water with strong carcinogenic effect will regurgitate into the tap water system! ”
After the news came out, many netizens expressed concern: in order to facilitate cleaning, usually put a piece of toilet in the toilet tank, according to this, can it continue to be used? Ms. Liu of Guangzhou said: "After seeing this news, I dare not use it again. ”
Backflow of water from toilet tanks is uncommon
The reporter learned that the so-called one-way water supply system refers to the general household water supply pipeline is diverted into the household by a main pipe, and then divided into multiple pipelines for water supply. The main pipe is supplied to the kitchen and toilet separately in the form of diversion. However, because the toilet belongs to the end of the facility, there is a pressure rod in the water tank to control the water level, and the valve is crushed after the water is full, and generally it will not flow backwards.
So, what situation is not the "general case"? According to experts, only when the valve exceeds the service life and is prone to damage. At this time, if the water stop occurs, or the water pressure fluctuates greatly, the pressure difference will occur inside the pipeline, and the water in the tank will flow back into the water supply pipe. If there is a toilet block in the water tank, then the tap water at home may "change color".
In general, if the water in the toilet tank is reversed, at least several conditions must be met: the valve is broken, the pressure difference is formed due to the water stoppage, and the water in the tank must be water.
No evidence to support "blue water carcinogenicity"
We can see that the toilet block label reads "Swallowing is harmful, if you eat by mistake, do not induce vomiting, drink a lot of water quickly, and seek medical attention immediately." "Does that mean it's going to cause cancer?"
The reporter found that many toilet block brands do not specify the product ingredients in detail, only accurate to the extent of "active agent", and what is the "active agent"?
It is understood that the main ingredients of the "active agent" will include alkyl sulfonate, dextrin and polyvinyl alcohol, which are actually common chemicals contained in many cleaning agents in life. Chemical experts said that these ingredients are relatively less toxic and have not found carcinogenicity. Even alkyl sulfonate, the substance that needs the most vigilance, has not shown signs of carcinogenicity in previous studies. Some brands may have sodium o-phenylphenol, a bactericidal preservative, but limited carcinogenicity has only been found in high-dose animal experiments. In other words, as long as frequent or prolonged contact is avoided, the harm of toilet blocks to the human body is not obvious.
Experts suggest that if there is a phenomenon of reverse flow, unscrew the faucet, put more water, and the water will naturally become clear. During the use of the toilet block, care should be taken not to touch the eyes, and remember to wash your hands after use, but do not have to be too nervous.