Particle board is composed basically of sawdust or wood chips and urea-formaldehyde glue. According to Knights, this inexpensive wood product will outgas formaldehyde virtually forever. If you have extensive amounts of unsealed particle board, you most likely have a lot of formaldehyde.

Is formaldehyde used in particle board?

Formaldehyde Facts

It is found in resins used in the manufacture of composite wood products like hardwood plywood, particleboard, MDF (medium-density fiberboard), and other building materials and insulation.

Is formaldehyde in particle board dangerous?

Pressed Wood Paneling & Particleboard Furniture

That formaldehyde then leaches into the air, leading to watery eyes, burning throat, and breathing difficulties. Worse, scientists warn that this dangerous chemical may be a carcinogen for humans, meaning it could cause certain types of cancer.