They are made of plastic/woven
Blue foods are rare, and blue bandage can be easily spotted if they fall in.
This is the most important reason we use blue bandage in the kitchen. like blue pipping bag or disposal glove are in blue too. Serving food with a bandage in it is very unhygienic and will lose you customers fast! Fabric or pink plasters might get lost in the food and not noticed until it’s too late.
Related to the previous reason, blue bandage usually contain a strip of metal. This makes the metal detectable, and in larger food processing environments, the product can be put through a metal detector.