Fiberglass is a manmade product, in use since the 1930s for filtration and insulation. In modern times, shower stalls, bathtubs, kayaks, boat hulls and many other objects contain fiberglass. When you saw, trim, or handle fiberglass, small fibers work their way into the skin of your hands and arms, creating an irritating itch.
Disrobe carefully, taking care not to drag your shirt over your arms or hands. Pressure on the skin can drive the fiberglass splinters deeper into your skin, making removal much more difficult.
Enter your shower and turn on the hot water and a small amount of cold water. Stand away from the water stream for several minutes. The goal is to work up steam in the enclosed space without getting your hands or arms wet. The steam opens your pores and increases the chances of the splinters falling out.
Adjust the water to a comfortable temperature and step back into the stream. Allow the water to run off of your arms and hands. If any of the splinters were loosened as a result of the steam, this step will rinse them away.
Add natural soap to a non-coarse loofah and gently brush the skin on your hands and arms. Do not apply pressure, as doing so will drive any remaining splinters deeper. Rinse your hands and arms with water to remove the soap.
Turn off the water and dry your hands and arms by lightly pressing the towel against the skin. Do not drag the towel.
Put on a loose-fitting, sleeveless shirt. If you are still experiencing irritation, move on to the next section.
Baking Soda Paste
Add 1/2 cup of baking soda to a bowl.
Add a small amount of water. Mix the baking soda and water into a paste with your fingers. If the paste is too dry and powdery, add more water. If the paste is too soupy, add more baking soda.
Dress any itchy areas on your hands or arms with the paste.
Allow the paste to dry for 25 to 30 minutes. Try not to move your hands or twist your wrist while the paste dries. The powder will harden around the exposed sections of the fiberglass splinters.
Rinse the dried baking soda off of your skin. Any fiberglass splinters that became attached to the paste will pull out and rinse away.