That new carpet smell: VOCs indoors and what EPA says about cancer

The smell that fills a room after new carpet goes in is chemistry you can detect with your nose. Materials and furnishings release volatile organic compounds. These are carbon-based chemicals that turn to gas at normal room temperature. Because they turn to gas, they reach your nose. Because they reach your nose, you notice them, sometimes for days after the material arrives.

EPA lists building materials and furnishings as indoor VOC sources. Others include paints, solvents, cleansers, disinfectants, dry-cleaned clothing, and office equipment such as copiers and printers.

EPA's statement on health needs to be read at the right level. The agency says some organics can cause cancer in animals. Some are suspected or known to cause cancer in humans.

Notice what that sentence does and does not say. It describes a large family of chemicals whose members vary a lot. It does not say new carpet causes cancer. EPA's page does not single out carpet as a cancer source.

A category with some carcinogens in it is not the same as every product in that category being a carcinogen.

The short-term effects EPA lists are the ones people report after a renovation:

• Eye, nose, and throat irritation
• Headaches, loss of coordination, and nausea

These are the real reason to ventilate. They show up fast enough that you can connect cause and effect yourself.

Two figures from EPA give useful scale.

Indoor levels of several organics average 2 to 5 times higher than outdoors. That is a steady background difference, present in ordinary homes even without any recent renovation.

Then there is the spike. During certain activities, like paint stripping, and for several hours after, levels may reach 1,000 times the outdoor background. That is not the everyday state of a house. It happens while you are actively doing something that releases a lot of solvent.

The gap between these two numbers is the most useful thing here. Everyday indoor air and active renovation work are different situations. They call for different responses.

The recommended steps are simple and effective:

• Increase ventilation when using products that release VOCs.
• Remove or seal sources of formaldehyde.
• Follow the product's directions carefully.
• Buy only the amount of a chemical you will use right away.
• Get rid of unused chemicals safely, through community collection programs.

For new carpet or new furniture, ventilation does most of the work. Moving air carries the compounds out instead of letting them build up.

If you are getting new flooring, cabinets, or furniture, the reasonable plan is not to cancel the project. Open windows, run fans, and let the room breathe while the smell is strong. If a family member has asthma, or is going through treatment that makes them feel unwell easily, having them stay elsewhere during the work, and for a while after, is a kindness that costs nothing.

Nobody can give you a specific cancer risk number for your new carpet, because EPA does not publish one, and we will not make one up. What the agency does give you is a clear picture: where indoor VOCs come from, that levels run higher indoors than out, and that ventilation is the tool you actually control.