Jiangsu faucet spot check more than half of the samples failed
Recently, the Quality Supervision Bureau of Jiangsu Province conducted quality monitoring on 56 batches of taps (ie, faucets) and found that more than half of the samples did not meet the quality standards. The quality risk analysis report just released showed that there were 31 batches of samples that did not meet the relevant standards, and the non-conformity rate was 55.3%. Among them, the non-conformity rate of 51 batches of commercially available products reached 60.8%; the conformity rate of 5 batches of products from manufacturers in Jiangsu Province was 100%.
Suzhou City Quality Inspection Institute undertook the inspection of chemical items in this monitoring task. What are the outstanding problems with the monitored faucets? Yesterday, the reporter obtained further analysis and answers from the Suzhou Quality Supervision Department.
Zinc alloy “self-increasing value” posing as copper alloy
Faucets can be divided into stainless steel, cast iron, plastic, copper alloy, zinc alloy, polymer composite materials, etc. according to different materials. Among them, faucets made of zinc alloy materials generally have a short life and poor stability. The national standard (GB18145-2014) of the “Ceramic Sheet Sealed Faucet” that will be formally implemented on December 1 this year stipulates that zinc alloy materials should not be used in the parts of the faucet that directly contact water. In this monitoring, the inspectors found that there is a phenomenon of using zinc alloy faucets as copper alloy faucets on the market.
The reporter learned from the Suzhou Quality Inspection Institute that there were 53 batches of faucets claiming to be “copper alloy” under risk monitoring. After material identification, 9 batches of samples were zinc alloys containing more than 95% zinc. The non-conformity rate was 17.0%. “In order to reduce costs, some manufacturers use a large number of zinc alloy materials, because zinc itself has a high density, and the product itself also has an electroplated layer. Ordinary consumers cannot distinguish from the feel, weight, and appearance, and it is easy to get mixed up in the market.” Said.
According to reports, the reason why zinc alloy is not suitable for direct contact with water is that the faucet made of this material has poor performance in coating corrosion resistance, pollutant precipitation and durability, and cracks will appear after a period of use. , Even cracking, causing water leakage, a small number of products will even produce internal cavity powder after a period of use. There are also great hidden dangers to the health of consumers. Excessive intake of zinc may inhibit the body’s absorption of iron and copper, causing iron deficiency anemia. It is especially important to note that excessive zinc is difficult to be excreted from the body. The bactericidal performance of copper alloy faucet is better, and it is also the mainstream faucet material currently used in European and American countries.
The lead precipitation of 20% copper alloy samples exceeds the standard
In addition to quality indicators such as energy saving, water saving, safety, and beauty, the amount of heavy metal precipitation in faucets is also a health and safety indicator that has attracted attention. Among the 53 batches of faucets that were declared to be copper alloys in this monitoring, 11 batches of samples detected lead precipitation exceeding the standard value, and the non-conformity rate was 20.8%.
It is understood that the lead precipitation of faucets mainly comes from copper alloy materials in contact with water. Some production companies will use recycled brass, such as key copper, car water tank copper, etc., for production, where the lead mass fraction is about 4% or even higher. Appropriate addition of lead to copper materials is mainly to improve the processability of copper materials and improve wear resistance. Lead in the copper alloy of the faucet can be directly dissolved into the water after contact with water. The faucet made of stainless steel has very low lead content, and the lead precipitation value is basically not measured. The material is closely related to lead precipitation.
Ding Hongliu, director of the physical and chemical laboratory of Suzhou Quality Inspection Institute, said that another heavy metal, chromium, was precipitated in excess of the standard during the faucet risk monitoring. Among the 53 batches of samples declared to be copper alloys, the total chromium of 2 batches exceeded the standard limit, and the non-conformity rate was 3.7%. The main reason for the excessive chromium precipitation is the residual precipitation of chromium in the welding seam and the surface coating, or the chromium contained in the material, which precipitates during immersion. According to the inspectors of the Municipal Quality Inspection Institute, although chromium is one of the trace elements necessary for living organisms, the existence of a large amount of chromium not only pollutes the environment, but also harms human health. All chromium compounds are toxic and are easily absorbed by the body and accumulate in the body. Excessive exposure to hexavalent chromium can cause kidney function and liver failure. However, in this risk monitoring, the inspectors did not find that hexavalent chromium exceeded the standard.
In this risk monitoring, no excessive precipitation of heavy metals such as arsenic, barium, hexavalent chromium, copper, mercury, selenium, and thallium was found.
Nearly half of the copper alloy faucet is not corrosion resistant
Among the copper alloy faucets monitored this time, 25 batches of products did not meet the level 10 requirements specified in the current standard GB18145-2003, and the non-compliance rate was 47.2%. This is also another major unqualified item of domestic faucet quality.
Since the faucet is generally used in the bathroom, kitchen, etc., it is relatively humid and contains detergents, detergents and other weakly acidic chemicals. During long-term use, corrosive liquids and gases will corrode the plating surface, which will cause pitting, bubbles, rust, corrosion spots and other defects, which not only hinder the appearance, but also the quality of the coating will directly affect the service life of the product , Finish and wear resistance.
There are many reasons for this kind of problem, mainly because some companies use low-grade brass and recycled materials to make the matrix. Some manufacturers use brass for the valve body of the faucet, while the handle and valve cover are made of low-cost and inferior materials such as cast iron. Such products often show no signs of corrosion on the valve body in the corrosion test, and the handle and other accessories will be damaged. Severely corroded.
How to distinguish zinc alloy faucet?
How to distinguish between fake and genuine zinc alloy faucets? Suzhou Quality Supervision advises consumers: understand the material and look at the price before starting.
A copper faucet costs at least 100 yuan
Let me talk about the price first. The reporter learned from the analysis report provided by the quality supervision department that based on the current unit price of about 16,000 yuan/ton for zinc alloy materials and 68,000 yuan/ton for pure copper, the cost of zinc alloy with the same weight is only 1/of copper. 3. Zinc alloy is easy to process and the processing cost is lower than copper alloy. According to industry standards, a faucet uses about 500 grams of copper, and the cost of bare copper for a faucet is almost 34 yuan, plus other components, labor, processing fees, freight, agency fees, water and electricity, etc., a normal copper faucet, directly The manufacturing cost will not be less than 100 yuan.
Take a look at the results of this risk monitoring: sample prices range from less than 100 yuan to 1,800 yuan, of which 31 batches of problem products are almost all concentrated in the range below 300 yuan.
Then look at the material. Since many zinc alloy faucets are made to be extremely heavy, the traditional method of distinguishing by weight is not accurate. Therefore, consumers are advised to use the following methods to distinguish: First, copper faucets are generally castings, and the inner wall of the product is not very flat; while zinc alloy faucets are injection-ground, the inner wall will be much smoother, and the inner wall has obvious separation .
If possible, you can also look at the color in an inconspicuous place. The color of zinc alloy is white, while copper alloy is yellow. It is particularly worth mentioning that when shopping online, consumers cannot visually observe the product, so you must be especially cautious. Choose a reputable and guaranteed merchant that supports 7-day unconditional return and exchange of goods. Keep the proof of purchase so that in case of problems Rights protection.
Letting off the overnight water in the faucet can reduce the content of heavy metals
There are also two points worth noting in terms of daily use: the amount of lead precipitation tested in accordance with the national standard refers to the amount of precipitation when water is in contact with the inner wall of the faucet for 16 hours. The shorter the contact time, the smaller the amount of lead precipitation. Therefore, in daily use, the lead content of the tap is far lower than the national standard, and consumers should not panic too much. When using, let off the water that stays in the faucet for a long time, such as overnight water, can effectively reduce the risk. In addition, solar water heaters and other heating devices are now used in homes. It is best not to use the hot water inside as drinking water, because the content of heavy metals in the hot water is higher than that in cold water.