Pressed wood (also called composite wood or engineered wood) refers to wood products made by binding wood particles, fibers, or veneers together with adhesives. Common types include plywood, particleboard, MDF (medium-density fiberboard), and OSB (oriented strand board).
Why pressed wood matters for indoor air quality: Traditionally, pressed wood products use urea-formaldehyde adhesives, which can off-gas formaldehyde into indoor air. Formaldehyde is classified as a known human carcinogen.
Types of pressed wood:
- Particleboard: Made from wood chips and sawdust (often in inexpensive furniture)
- MDF: Denser, made from fine wood fibers (common in cabinets and moldings)
- Plywood: Layers of wood veneer glued together (used structurally)
- OSB: Oriented strand board (used in construction)
Choosing safer pressed wood:
- Look for CARB Phase 2 compliant products (required by law in California)
- NAF (No Added Formaldehyde) is even better
- ULEF (Ultra Low Emitting Formaldehyde) products exceed CARB standards
- Solid wood alternatives eliminate the concern entirely
If using pressed wood, ensure good ventilation and allow new products to off-gas before bringing them into living spaces.