Depends mostly on the wavelength. UV of ~350-400nm Will pass through most plastics. But less than ~300nm would be absorbed. Here's some graphs of the transmission. http://usa.dupontteijinfilms.com/wp-content/uploads/2017/01/Mylar_Optical_Properties.pdf. Poly-carbonates do block UV, not totally but much more so than acrylic. But as other's have commented the UV will degrade it over time. This is the case of all carbon based plastics. The good news is, your windshield blocks virtually all damaging UV radiation. contains UV inhibitors that protect the plastic and as a result also protect any transmission of UV through it. So The outside ambient UV-A radiation, along with UV-A radiation behind the front windshield and behind the driver’s side window of all automobiles, was measured. The years of the automobiles ranged from 1990 to 2014, with an average year of 2010. The automobile dealerships were located in Los Angeles, California. Thickness doesn't have as much to do with UV transmission as the properties of the material. Keep in mind they can block almost 100% of UV rays with a very thin coating on your eyeglass lenses. Although, like you, I would guess that a clear (no tint) plastic film would allow transmission of a good deal of UV. But guesses don't count. The most effective UV-blocking curtains are the type that block up to 98% of UV rays. While UV rays are beneficial to people, they are not good for antique fabrics or books. They damage paper, leather, and skin. They can also cause macular degeneration, which can lead to loss of sight. R4JnTd. Energy-efficient window attachments are important for both new and existing homes. About 30% of a home's heating energy is lost through windows. In cooling seasons, about 76% of sunlight that falls on standard double-pane windows enters to become heat. Window coverings can help with this loss of energy by providing comfort, regulating Ultraviolet (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than soft x-rays. The “near” UV spectrum (200-400nm) is divided into three types of radiation, UVC, UVB, and UVA rays, based upon wavelength: UVC: 200nm – 290nm. UVB: 290nm – 320nm. UVAII: 320nm – 340nm (short-wave UVA) The good news is, your windshield blocks virtually all damaging UV radiation. contains UV inhibitors that protect the plastic and as a result also protect any transmission of UV through it. So Sunglasses do not totally block UVR and should be combined with additional protection means. 3D modeling allows estimating UVR exposure of highly sensitive small skin zones, chronically exposed Thick curtains (not the white, see-through ones) are more than enough to block UV rays. If your blinds are not letting visible light through, there's almost no chance uva is coming through. Light curtains can let some UVA through, if they are thin, but it will reduce no matter how thin. Go by how much light you see through the curtain.

does plastic block uv rays