The Case of the Sliding Glass Safety Window
Question:
Dear Glass Detective,
Should a sliding receptionist window in a doctor’s office be tempered glass?
Sincerely,
Spencer
Answer:
Dear Spencer,
Let me begin by thanking you for contacting the Glass Detective with your very timely and important question. Many people have been asking questions about office partitions since the advent of the COVID-19 pandemic. Sliding glass reception windows of all types have been in use in offices for as long as I can remember. These types of windows often are referred to as “pass-thru” windows if for no other reason than the fact that you can slide one part of the window over the other to allow a “passing thru” of paperwork, merchandise, or whatever else is involved in the transaction taking place. These types of installed glass partitions are also sometimes called “bypass windows” or “transaction windows”. They are found in offices of all sorts and are easy to install and maintain for the most part.
As for your question as to whether or not tempered glass should be used, the building and safety codes that have long been in place requires that any glass installation in a “hazardous location” needs to use glazing products that meets the standard for what is defined as “safety glass.” Safety glass products include tempered glass, laminated glass, some polycarbonate, and certain plastics. Building codes define what hazardous locations are, but the interpretation is sometimes in the eye or mind of the local code officials. I think the problem here (though I know some may disagree with me), is that there is a little bit of ambiguity about the requirement for safety glass in these (pass-thru) locations because of the way some codes have been interpreted in the past. I have heard arguments as to why the type of window you are referring to does not have to technically be safety glazed but the argument for safety glazing is, in my opinion, both practical and (by code definition) required. Also, at some point, common sense would lead to the conclusion that these types of windows need to be installed in such a way as to provide safety to the people that use them. Be sure to check with local officials to obtain the latest code requirements in your area before installation.
Having spent time in the reception area of doctor’s offices and some businesses that use these types of windows as well, I have personally witnessed people bumping into them while doing some type of transaction with the person on the other side of the window. I have also seen parents holding children in their arms while standing at these windows. In a busy office, these windows almost have someone standing at them and passing all kinds of things through them all day long. We know that tempered glass is 4-5 times stronger than non-tempered glass of the same type of thickness. Also, tempered glass will break into small relatively harmless small pieces if it breaks. So given these two facts, we should quickly see the benefits of using tempered glass products. It is hard for me to understand why someone wouldn’t want to use tempered glass for these types of windows from a practical standpoint. I’m not intending to downplay the usefulness of laminated glass for these window assemblies but as a personal preference, I would prefer to see tempered glass in this application for the strength factor mainly. However, I am also aware of some locations in which the laminated safety glass approach could be preferred because the laminated glass will tend to stay together (at leads for some time and to some extent) after it is broken. I have seen polycarbonate/acrylic/plastics used in these types of windows as well but because these products can be harder to clean and less rigid, I have not witnessed a great many installations of this type.
Another question that arises when discussing these types of installations is “How can a person verify that a piece of glass that is in one of these windows is indeed a safety product?” The simple answer (as required by code) is that these pieces of glass are to be permanently labeled with a logo indicating what the glass is and who manufactured it. For furniture and/or other aesthetic purposes, an “on file labeling certification statement” exemption from the labeling requirement can be obtained, but in a reception pass-thru or sliding window, I think the label should be in place and you should be able to find this in a corner of each piece of the safety glass installed.
Lastly, the typical reception or pass thru window in an office’s reception area is not very large. Further, the glass installation procedure for these windows is quite simple. The point I am trying to make here is that the material and labor cost that goes into one of these windows is not very high. So, in my opinion, there is absolutely no excuse for not installing a safe and effective glass product in these reception type window applications. The cost differential between safety and non-safety products here is not something that should even have to be considered in my opinion.
I hope this commentary is of some benefit to you and I thank you again for making contact with the Glass.com Glass Detective with your question.
One Response
Having been in the Glass Business and installed tens if not hundreds of these my take on using tempered safety glass in doctor’s sliders is, Tempered safety glass is the worst option of the three, Annealed Plate Glass, Tempered Safety Glass and Laminated Safety Glass.
I have had to repair three sliders in my career where tempered glass was used and in all three cases the office clerk/nurse received eye injuries. They are usually sitting down at there desk when the tempered safety glass exploded sending small glass shards into there eyes causing serious injury.
In retrospect I have been called to service broken plate glass and or laminated glass sliders many times without any injury at all. By far the safest option is laminated safety glass like what is used in automobile windshields it my crack but it stays together