Quick tips
Prefer insulation made of natural materials, recycled cellulose, or minerals. Good options include cork, wood fiber, sheep’s wool, hemp, and certain fiberglass and mineral wool.
Avoid plastic foam insulation, whether board or spray-applied.
For board insulation, prefer expanded cork, wood fiber, and unfaced formaldehyde-free fiberglass or mineral wool.
For blown and batt insulations, consider the binders and facers used.
Avoid products with formaldehyde binders or flame retardant facings.
Use mechanical methods, like fasteners, over adhesives for installation.
Pick products that provide full content details via Health Product Declarations (HPDs).
Ranking
Expanded Cork Boards
Blown-In Wood Fiber (Loose Fill and Dense Pack)
Blown and Batt Sheep’s Wool
Hemp Fiber Batts
Wood Fiber Batts and Boards
Blown-In Fiberglass or Mineral Wool (Loose Fill, Dense Pack, and Spray-Applied)
Unfaced Fiberglass Batts
Formaldehyde-Free Mineral Wool Batts and Boards
Blown-In Cellulose (Loose Fill)
Unfaced Formaldehyde-Free Fiberglass Boards
Kraft-Faced Fiberglass Batts
Cellulose/Cotton Batts
Blown-In Cellulose (Dense Pack and Wet-Blown)
PSK or FSK-Faced Fiberglass Batts
Standard Mineral Wool Batts and Boards
Standard Fiberglass Boards
Halogen-Free Polyisocyanurate Boards
ASJ- or FSK-Faced Fiberglass Boards
Expanded Polystyrene (EPS) Boards
Standard Polyisocyanurate (Polyiso) Boards
Extruded Polystyrene (XPS) Boards
Spray Polyurethane Foam (SPF)