A lot of people are worried about volatile organic compounds, better known as VOCs. These compounds can cause health issues like allergies and asthma—some have even been linked to cancer. Yet because you often can’t see or smell them, it’s difficult to know when your air has been compromised. Especially now that most new homes are built airtight for energy efficiency, VOCs are often trapped inside. Learn how to identify and avoid VOCs found in most American homes.