Well, fiberglass is basically a type of insulation made from super-thin glass fibers. It's used in all sorts of things, from building materials to car parts, because it's lightweight, strong, and can withstand extreme temperatures. But, as we've established, it's also super itchy, so you gotta be careful when handling it.
So, how do you stop the itch from fiberglass? Well, the first thing you should do is shower or wash the affected area with some warm water and mild soap. It's like washing off a bad sunburn - you just want to get all the irritating stuff off your skin. And, just like with a sunburn, you should avoid scratching, 'cause that can just make things worse.
Fiberglass Skin Irritation Treatment at Kevin Davidson blog
Another thing that might help is applying some calamine lotion or hydrocortisone cream to the itchy area. It's like putting ice cream on a sore throat - it just makes everything feel better. These creams can help reduce the inflammation and itching, so you can get back to your day without wanting to scratch your skin off.