Feature X05: Enhanced Material Restrictions within the WELL Building Standard specifically targets the reduction of harmful substances in building materials, including formaldehyde, which is restricted in products such as ceilings, wall panels, insulation, furniture, and millwork. Formaldehyde is a volatile organic compound (VOC) known for its adverse health effects, including irritation of the skin, eyes, nose, and throat, and potential long-term respiratory and carcinogenic effects. By restricting the use of formaldehyde in building materials, the WELL Building Standard aims to improve indoor air quality and protect the health and well-being of building occupants.