Fiberglass & Mineral Wool Insulation

Fiberglass and mineral wool (rock or slag wool) are made of tiny glass or mineral fibers. They itch, scratch the skin, irritate the eyes, nose and throat, and in dusty work can reach the lungs. Most of the harm is short-term and avoidable with the right clothing, respiratory protection and work methods.

• Insulation Installers
• Remodelers
• HVAC Techs
• Homeowners

What the hazards are

• Skin irritation: fibers poke into the skin and cause itching, redness and rash. This is a mechanical effect, not an allergy, and it usually fades after exposure stops. See Skin Disease & Dermatitis.
• Eye irritation: fibers cause scratching and watering. Rubbing makes it worse. See Eye Injuries.
• Nose, throat and lung irritation: dust causes coughing, sore throat and a stuffy nose. Heavy exposure can aggravate asthma and bronchitis. See Occupational Asthma.
• Binders and facings: some products use formaldehyde-based or other binders, and some have foil or paper facings that make dust when cut. Heat can release fumes the first time a newly insulated surface gets hot. See Formaldehyde.
• Other hazards where it is installed: attics and crawl spaces bring heat, falls through ceilings, low light, nails, wiring and sometimes rodents and mold. See Rodents & Hantavirus, Mold and Heat Illness.

Product labels and safety data sheets state the manufacturer's hazards and the recommended protection. Read the SDS for the products you use. See Safety Data Sheets.

Protect your skin and eyes

• Wear loose, long sleeves and pants with closed cuffs and collar. Tight clothing presses fibers into the skin.
• Wear gloves that fit and a hat or hood overhead. See Hand Protection.
• Wear safety goggles (not just glasses) when working overhead or in dusty air. See Eye & Face Protection.
• Use disposable coveralls in dusty jobs such as blowing insulation or removing old material.
• Don't rub or scratch itchy skin or eyes. Rinse eyes with clean water. Wash skin with cool water and mild soap; hot water opens pores and can make the itching worse.

Protect your lungs

Wear at least a NIOSH-approved particulate respirator (such as an N95) for cutting, tearing out or blowing in insulation, or as your hazard assessment and SDS require. Dusty work like removing old insulation or blowing attic insulation may call for a higher level. Respirators must be fit-tested and medically cleared where your employer requires a program. See Respiratory Protection, Fit Testing and Respirator Filters. Keep other people out of the area while you work.

Work methods that cut dust

• Cut batts with a sharp knife on a board, compressing them slightly. Avoid tearing and shaking.
• Don't blow or sweep dust. Use a HEPA vacuum or damp cleaning. See Dust Control Methods.
• Keep material in its bags until needed and bag the scraps right away.
• Ventilate the area and shut off HVAC systems that might spread fibers while you work. See Ventilation.
• For blown-in insulation, keep the hose and hopper secured, protect people below, and use lighting and a safe walking surface across joists.
• Cover recessed lights and wiring as the fixtures and codes require, and keep insulation away from heat sources.

Attics and tight spaces

• Walk only on joists or boards; ceiling drywall won't hold you. Lay down a walkway.
• Watch for heat: attics can be dangerously hot. Work in the morning, take breaks and drink water. See Heat Index & WBGT.
• Check for live wires, nails, vents and rodent droppings before you crawl. See Hidden Wiring.
• Use a work light and a buddy, and tell someone where you are. Some spaces are confined spaces. See Confined Spaces.

Clean up and wash

• Remove coveralls before you leave the area and bag them. Wash work clothes separately from family laundry. See Take-Home Contamination.
• Shower and rinse with cool water after work. Wash hands and face before eating, drinking or smoking.
• See a doctor if you have a persistent cough, breathing trouble, lasting rash or eye pain.

Insulation work checklist

• I've read the SDS and know what the product contains
• I wear loose long sleeves, gloves, goggles and a fitted respirator
• I cut on a board, avoid shaking and use HEPA vacuuming or damp cleanup
• I walk only on joists or boards in attics, and watch heat and wiring
• I wash with cool water and launder work clothes separately

Last updated: October 5, 2026