VOCs — volatile organic compounds — are carbon-based chemicals that evaporate into the air at room temperature. They come from a long list of ordinary household sources: fresh paint and finishes, new cabinetry and furniture, carpets, cleaning products, air fresheners, and many building materials. Because so many sources sit indoors, the EPA's exposure studies found common VOCs run about two to five times higher inside homes than outside — and during and just after activities like paint stripping, levels can briefly spike to a thousand times outdoor background.
The health picture ranges from eye, nose, and throat irritation and headaches at common levels to more serious effects from some compounds (formaldehyde is a well-known example) at higher or prolonged exposure. The 'new house' or 'new furniture' smell is largely VOCs off-gassing.
The control strategy is specific, because VOCs are gases, not particles — and most ordinary filters, including MERV 13, are built for particles and do little for them. The EPA's hierarchy applies cleanly: source control first (choose low-VOC products, let new materials off-gas before install, store solvents outside living space), then ventilation to dilute and exhaust what remains — an ERV/HRV sized to ASHRAE 62.2 helps here. Activated-carbon filtration can adsorb some gas-phase VOCs as a supplement, but a contractor who answers a VOC complaint with a particle filter alone has missed the mechanism.