Which of the following factors can cause crazing in transparent plastic windows?

Crazing in transparent plastic windows is primarily caused by exposure to UV light. Over time, UV radiation can break down the chemical bonds in the plastic material, leading to micro-cracks or crazing on the surface. This not only affects the appearance of the window but can also compromise its structural integrity and clarity.

While other factors such as low temperatures, high humidity, and over-polishing can contribute to the deterioration of transparent plastics, they are not the primary cause of crazing. For instance, low temperatures might make the material more brittle but do not directly cause the fine cracking typical of crazing. High humidity may affect the adhesion of certain coatings on the surface, but it doesn’t initiate the crazing process itself. Over-polishing can lead to a reduction in surface thickness and potentially introduce scratches, but it is the UV exposure that fundamentally causes the chemical changes leading to crazing. Thus, focusing on protecting transparent plastic windows from UV exposure is crucial for maintaining their clarity and lifespan.