ELI5: Explain Like I'm 5

Environmental stress cracking

Environmental stress cracking (ESC) is a type of damage that can occur to materials when it is subjected to stress. It happens when the material is exposed to certain chemicals, such as water or air, as well as physical stress, such as from temperature changes or from being bent too far. The chemicals or physical stress can cause tiny cracks in the material, which makes them weaker and less able to hold up to pressure and use.