Is plexiglass bulletproof?

Standard plexiglass, which is a brand of acrylic glass, is not bulletproof in its common, thin forms. However, thick sheets of acrylic can be manufactured to be bullet-resistant. For example, a sheet of acrylic that is 1.25 inches thick can achieve a UL Level 1 rating, meaning it can stop several rounds from a 9mm handgun. Because acrylic is a thermoplastic, it is much tougher and more impact-resistant than standard glass. It is often used in 'bulletproof' applications like bank teller windows or convenience store shields because it is lighter and has better optical clarity than very thick laminated glass. However, for higher levels of protection (stopping rifles or more powerful handguns), acrylic is usually combined with layers of polycarbonate or other materials in a laminated structure. It is important to distinguish between 'shatter-resistant' plexiglass, which is thin and used for safety, and 'ballistic-rated' acrylic, which is thick and engineered for security. So, while your average piece of plexiglass from a hardware store won't stop a bullet, specialized, thick acrylic products are a staple in the security glazing industry.