Glass safety issues have always been people’s concern. One of the most frequent questions we get from the client is: Is tempered glass furniture safe?
Tempered glass furniture is safe, as it is made of tempered glass. According to Wikipedia, tempered glass is a type of safety glass, it is less likely to break and less threatening if it does break. Tempered glass fragments are less to cause injury, which is proven by ANANSI Z97.1 impact tests.
Please continue reading to learn why tempered glass is safe and how it protects us when it breaks.
Why is tempered glass a type of safety glass?
High Strength
During the production, tempered glass is heated to at least 600 °C (1,112 °F) for 2 to 25 minutes, then is cooled by a high-pressure air jet from all angles for 3 to 10 seconds. The rapid cooling causes the outside surface of tempered glass to cool and compress faster than the center, resulting in more surface and edge compression.
This process makes tempered glass three to four times stronger and safer than normal annealed glass, has more than 10,000 pounds per square inch (psi) of compression on the surface, and more than 9,700 psi of edge compression.
Please refer to our other post for additional information on the toughness of tempered glass.
Impact-resistance
As a type of safety glass, tempered glass must pass the impact test of EN12600 and ANSI Z97.1.
EN12600 impact test is a European-wide impact performance standard for glass, specifying a pendulum impact test method for single-pane flat glass used in buildings.
The EN 12600 test consists of dropping a heavy object at three heights, 190 mm, 450 mm, and 1200 mm. The test weight will be dropped upon a standard-sized glass panel, and its classification will depend on when the glass breaks.
As a type of safety glass, tempered glass must pass the impact test of EN12600 and ANSI Z97.1.
EN12600 impact test is a European-wide impact performance standard for glass, specifying a pendulum impact test method for single-pane flat glass used in buildings.
The EN 12600 test consists of dropping a heavy object at three heights, 190 mm, 450 mm, and 1200 mm. The test weight will be dropped upon a standard-sized glass panel, and its classification will depend on when the glass breaks.
The test will also determine the level of “safe breakage” of the glass, where proven safety glass will not have huge shards but rather small fragments that do not cause excessive harm.
It divides glass items into three primary categories based on their impact strength, with 1B1 representing the highest level of impact resistance. And the fully tempered glass has a Class 1B1 rating, making it one of the safest glass products.
In addition to BS EN 12600 in Europe, the United States offers a similar qualifying test known as ANSI Z97.1.
The American National Standards Institute (ANSI) Z97.1 is a safety performance test specification and method for safety glass used in structures and construction. Aiming to improve security and decrease the risk of humans being injured when glass breaks.
Besides the impact test, ANSI Z97.1 also checks the size, volume, and weight of shattered tempered glass fragments, counting and measuring them. Please read our other article to get the full impact test of ANSI Z97.1.
Smaller threat glass fragments
The safety of tempered glass is not only reflected in its less likely to break, but also in the fact that it poses less threat when it breaks. Tempered glass passed the ANSI Z97.1 test, which means that its fragments are relatively harmless, and less likely to cause injury.
The glass undergoes intense high-temperature tempering and quick cooling during the manufacturing process. Quenching cools the center of the glass much quicker than the outer, resulting in compressive forces in the outer and contraction and tensile stresses at the center.
Compressive pressures increase the strength of tempered glass. The higher the pressure, the smaller the fragments of glass that break.
Compared to conventional annealed glass, tempered glass shatters into thousands of little, fairly harmless, non-sharp fragments when it breaks. These little particles are usually unlikely to cause harm.
Moreover, most of the time, these particles interlock with relative particles. They do not fall or splash easily, reducing the risk that sharp shards or glass splashes injure someone.
Should the glass table top be tempered?
The United States Consumer Commission has no material requirements for glass furniture, furniture manufacturers can use any glass, and it does not need to be announced to the public. Only a voluntary ASTM standard requires using tempered glass when the glass is used as a tabletop.
However, if the glass tables are not strong enough, they can easily become a health danger, especially in homes and public areas with children.
A study published in the American Journal of Surgery by Rutgers University found that glass table accidents are frequent, with yearly reports of over 2.5 million cases. Glass tables shatter can cause serious injuries, even life-threatening ones.
The study collected data from NEISS and Level 1 trauma centers from 2009~2015. They Classified injuries according to defective glass type, severity, and involvement using predetermined criteria.
3,241 cases from NEISS, it shows One-third of the harm was directly traced to the incorrect glass table. 15% were dead serious.15% were serious. Commonly happens between the ages of 7 and 20, with the head and upper extremities.
The study also looked at 24 trauma center cases. 34% presented with serious organ, body cavity, or joint space injuries, and 58% required surgical intervention. The mortality rate at 30 days was 8%. Over 54% required hospitalization.
And most importantly, the study noted that, in a retrospective review of a cohort of urban pediatric patients, over half of the traumas involving glass tables could be prevented using reinforced tempered glass, and modulation of glass quality can prevent harm.
Therefore, tempered glass must be used for glass table tops in the home (particularly if there are load-bearing requirements or children are there). It can effectively lower the accident rate. Even if it were to shatter, its less harmful fragments would reduce the risk of severe cuts, punctures, and deadly accidents.
Source:
https://en.wikipedia.org/wiki/Tempered_glass
https://www.cpsc.gov/s3fs-public/1801-Tempered-Glass-Safety-Alert.pdf
https://www.sciencedaily.com/releases/2020/09/200915090112.htm
