Safety screens are used in many chemistry and physics lessons to protect pupils and teachers from being struck by debris or objects from demonstrations.
Most nowadays are made from polycarbonate, the same material used to make police riot shields.
Only screens that are sold as 'safety screens' should be used for this purpose as some other types of transparent plastics may shatter or crack if struck. Even purpose made polycarbonate screens are prone to getting scratched through use which may affect the ability to see what is going on through them.
Never clean the screen with any abrasive chemicals or scourer, just use soapy water and a soft cloth if grimy.
Many practical demonstrations will insist on using a safety screen and/or safety glasses. If demonstrating using a safety screen make sure the audience AND you are protected adequately. Follow safety guidance thoroughly and seek advice from CLEAPSS, the ASE or the SSERC if in any doubt.
Two types are pictured here, the first (see Fig 1) shows a bent screen which is fixed in position. These should be used in conjunction with clamps (see Fig 2) which hold the screen firmly in place ensuring that it does not fall over during use. The second type (see Fig 3) shows a screen with hinges. Each side base incorporates a heavy stand which acts as a supporting foot. These have the added advantage that you can set them up to bend around the equipment that is being demonstrated instead of using a flat screen in front.
Whichever screen you use, make sure it is not set up too close to the equipment especially if the equipment is hot or involved hot objects. This may fog or permanently warp the screen.