Frequently Asked Questions
Q: What is safety rated glass? When is it required?
A: Impact resistant safety glass does not make glass shatterproof, it will simply keep the glass in one piece to prevent or limit injury if breakage occurs. Safety glass is required when glass occurs in a door, within 24 inches of a door, or within 18 inches of the floor. Typically, with regular plate glass, this would mean the glass needs to be tempered. However, it is not possible to temper lead glass. Fortunately, a safety rating can be achieved in other methods; one option is to laminate a layer of annealed plate glass to the lead glass. The other method is a surface applied security film, which is the most cost-effective way of producing x-ray lead safety glass. Our safety glass meets ANSI Z97.1 and CPSC 16 CFR 1201 Category I unlimited which means we can achieve any size in an interior window. We are not limited by the typical 9 square foot maximum that other companies have.
Q: Is there a standard lead thickness for x-ray rooms?
A: There isn't a standard lead thickness required for radiation imaging rooms. Each room has many factors that contribute to the lead shielding requirements. Some of these factors are: the energy level of the machine (how much radiation it produces and which direction it is pointed), work load (how often the machine is used), the existing construction of the room (drywall and stud walls require more shielding than concrete walls), surrounding rooms (walls shared with a children's care unit will require much more shielding than walls shared with a storage closet), and other variables are taken into consideration when a physicist is calculating the lead shielding requirement. See next question for more info.
Q: What is a shielding report? How do I find out the lead equivalency required?
A: A radiation shielding report is a document written by a radiation physicist. It describes the lead thickness or lead equivalency required on each wall of your imaging room. Federal law stipulates that every facility must have a shielding evaluation done for every imaging room. They are also required if something changes in the room, like replacement of an imaging machine. In some areas, this can be handled by your county health department. Sometimes, the company you bought the x-ray machine from can acquire one for you. Due to a perceived conflict of interest, we cannot be involved in the shielding report acquisition. But if you have a shielding report and don't know how to decipher it, you can email it to us with your quote request and will we quote the proper products.
Q: Can I use x-ray shielded glass in an exterior application?
A: Yes, but not by itself. Lead glass is porous and fragile. It cannot be exposed to the elements. We make IGU's (insulated glass units) comprised of tempered glass for the exterior pane and x-ray lead glass for the interior pane.
Q: Is lead acrylic an option?A: We do not offer lead acrylic for several reasons:
- It ends up needing to be 6 times as thick and lead glass (2" thick acrylic vs 5/16" thick lead glass)
- It scratches much more easily
- After about a year, it becomes so dark from the radiation exposure that it's similar to looking through a jar of honey. Lead glass does not have this problem.
- We don't offer any lead glass alternative because there are only downsides and nothing positive.
Q: Does x-ray shielded lead glass have a tint? Is the a clear option?
A: All lead glass has a yellow hue due to the heavy metal content required to shield radiation. It's simply not possible to shield radiation and not have a yellow hue. But lead glass actually has the same amount of yellow as regular plate glass has of green. The bright edge of the glass creates the illusion that there is an extreme tint. Most people don't notice the color of plate glass because the edge of the glass is concealed in a frame, and it's the same in an x-ray room. It's nearly impossible to notice the color of lead glass when it's installed in a window frame. Below is a photo comparison of plate glass (top) and lead glass (bottom).