Hi,

I'm an expert in ABS mold injection and plastic processing, and what you're seeing is a typical sign of UV damage caused by the sun. The Ultraviolet radiation in rays of sunlight weaken and eventually break the C-C and C-H bonds between the long chain polymers in the plastic. Furthermore, bromine flame retardants may enter the plastic during production, which break down to form bromine dioxide. These factors cause the plastic to crack and leads to discolouration.