For many people, bath time in the evening can be the most relaxing time of the day. Think about it, you are tired all over, rubbing bubbles and singing, and suddenly you are blown up by the bath screen......
This is not alarmist. In May, a 16-year-old girl suddenly burst the screen in her bathroom while showering at home, leaving four wounds on her body that needed to be stitched up, requiring more than 20 stitches [1].
And if you search for keywords, it's not uncommon for shower rooms to burst.
In 2022, a man burst the glass door of the shower room while taking a bath in the hardcover room he purchased, and he received more than 20 stitches [2]; In July 2023, an eight-year-old boy was injured when the glass of the shower room of a hotel in Yunnan burst [3]; In October 2023, a woman checked into a hotel in Dalian when the bathroom glass burst and ruptured the tendon in her right foot [4]......
Bathroom glass door explosions are not uncommon / Picture Worm Creative
How can a good glass door explode and become a "time bomb"?
There is a clear national standard for the category of shower room glass. According to the requirements of the standard, tempered glass, semi-tempered glass, and flat glass can all be used as shower room glass [5]. However, compared with semi-tempered glass and flat glass, tempered glass has more technical requirements and a higher safety factor.
As the saying goes, "100 tempered into steel", it is this bluffing name plus material, tempered glass is synonymous with "safety" in the hearts of many people. Therefore, the vast majority of people will also choose tempered glass when purchasing and installing shower room glass. Even the staff of the Dalian hotel where the bathroom glass exploded were puzzled: "The hotel uses tempered glass, and it can't be broken." ”
Unfortunately, even if it is "as hard as steel", tempered glass is not as "indestructible" as you think. Even when there is no interference from external forces, it will "blow up" on its own. The probability of self-explosion of tempered glass is not low, and the general perception in the industry is about 0.3% [6].
The reason why tempered glass will explode is inseparable from a concept - stress.
To put it simply, tempered glass adds a "compressive stress layer" to flat glass to increase the strength of the glass [7]. However, a study jointly conducted by a company and the China Architectural Glass and Industrial Glass Association has shown that the self-explosion rate of tempered glass is also proportional to the stress, and the higher the stress, the higher the self-explosion rate [8].
The country has strict standards for the manufacture of tempered glass
The minimum requirement for the stress value of tempered glass in the European Union is 75MPa, and that in the United States it is 69MPa, while the domestic requirements for the stress value of tempered glass are relatively higher, which needs to reach more than 90Mpa [8].
In addition, high stress requirements are not necessarily bad, as high stress will cause more fragments when tempered glass is broken, and the smaller the fragments, the less dangerous it poses to the human body [8]. National standards also require that safety glass should be guaranteed to be more than 40 particles per 50*50mm area [9].
So why is the glass in the shower room more "bursting" than the windows in the interior and the sliding doors in the kitchen?
This has to mention the temperature difference when taking a bath.
Although tempered glass has been beaten by a thousand degrees of high temperature, the impurities in it and itself cannot be "in step".
A study by the China Academy of Building Materials Sciences showed that tempered glass retains an impurity called "nickel sulfide particles" during the manufacturing process, which is one of the important reasons for self-explosion [10]. When the temperature changes, the volume of nickel sulfide expands, and the surrounding glass will also produce microcracks, and the balance inside the tempered glass will be disrupted, and it will explode [11].
Then there is the issue of the shape of the glass in the shower room.
The curved bathroom glass is more easily deformed, thus self-detonating / picture worm creativity
Most of the ordinary building tempered glass is flat, but the bath screen in the bathroom, in order to be beautiful or save space, is often designed with a certain curved arc.
According to the research of the China Building Standard Design and Research Institute, even if this special-shaped tempered glass meets the requirements of the standard, it is easy to produce large deformation in the process of use, which adversely affects the force on the panel, and is more prone to self-explosion [12] .
Even the installation of shower glass is full of pits.
Don't think that the installation of tempered glass is the same as the installation of wooden boards, the state has specific technical regulations for the installation of architectural glass. There should be gaps on the four sides of the tempered glass when it is installed, which also leaves some space for glass deformation [13]. And how much of this gap should be left is likely to depend on the master's own experience in actual implementation.
The procurement of tempered glass must not only comply with national standards, but also the installation needs to be carried out by professionals
What's even more terrifying is that the quality of the bathroom glass you buy is likely to be not up to par at all.
Although tempered glass may explode due to the temperature difference caused by bathing, qualified tempered glass theoretically needs to pass the temperature test. That is, at a temperature of 200 degrees, it is directly immersed in water at 0 degrees Celsius without damage [9].
The difficulty is that there are too many unqualified tempered glass. According to the results of the third batch of national supervision and random inspection of tempered glass product quality in 2018, the unqualified discovery rate of 91 batches of construction tempered glass products produced by 91 enterprises in 15 provinces and municipalities including Beijing and Hebei was 17.6% [14]. This probability may not seem high, but as long as it happens, it is scary enough.
It's not hard to stay safe. Choose a reliable bathroom brand, refer to the stress value, try to choose a straight bath screen, find a professional installation master, especially when buying, you should look for the 3C mark, tempered glass is the product range implemented by the "Compulsory Certification Management Regulations", as long as there is a 3C mark means that it has passed the national safety certification certificate.
In addition to these, in fact, it is also possible to add explosion-proof film to tempered glass.
In the latest national standard of "Shower Room Glass", laminated glass and tempered film glass technology have been added, and explosion-proof film is pasted on the purchased tempered glass, which can effectively prevent glass slag from flying and reduce the damage of glass fragments to the human body [5][15].
However, in order to avoid being pierced into a sieve, you have to worry so much about taking a shower, it is really better to buy a plastic cloth shower curtain! You tell me?