There are a wide variety of toxic chemicals lurking in your home, and while you can take steps to minimize them, one of the most prevalent chemicals in your home isn’t easy to get rid of. Formaldehyde, a volatile organic compound that’s emitted in low levels by a variety of household building products and furniture, may cause cancer in humans and has been known to trigger asthma attacks and allergic reactions when present in high levels. A common component of glues that hold pressed-wood or particleboard furniture and cabinets together, it’s also emitted by natural gas stoves, carpet glues, flooring glues, caulks, sealants, paints, furniture finishes, and the water-and-stain repellent finishes applied to upholstery and clothing.

Although governments regulations have reduced the amount of formaldehyde used in insulation and particleboard furniture, the sheer number of potential formaldehyde emitters found in the average home makes the chemical difficult to avoid. The good news: you have a cheap, easy, green tool at your disposal to help get rid of it. Add these seven household plants that NASA scientists have discovered help remove formaldehyde and purify air to your home for a safer, cleaner atmosphere.

Boston Ferns

Boston Ferns remove more formaldehyde than any other plants. They’re also highly efficient at removing other indoor air pollutants, such as benzene and xylene—components of gasoline exhaust that can migrate indoors if you have an attached garage. The downside to these plants is that they can be finicky. You need to feed them weekly in seasons when they’re growing, monthly during the winter, and they like to be watered regularly. Depending on the humidity and moisture levels in your home, you may need to water them or mist their leaves daily.

Snake Plant

The Snake Plant or Mother-in-Law’s Tongue, is one of the most recommended plants for improving air quality. The optimal place to keep this relatively inexpensive and low-maintenance plant is the bedroom, because it converts CO2 into oxygen at night. In addition to helping lower carbon dioxide, the snake plant rids air of formaldehyde and benzene.

English Ivy

Grown outdoors, English Ivy is an invasive species that can damage your home’s exterior and tear off your gutters, but bring it inside, and it becomes an effective formaldehyde remover. Thanks to its ability to climb structures, it’s easy to grow as topiary and use as a decorative element in your living spaces. English Ivy like part sun and part shade, so it’s a good plant to try indoors and isn’t as temperamental as Boston Ferns. Occasional watering and misting during the winter will keep it healthy.

Spider Plant

A good option for beginning gardeners, the spider plant reproduces quickly, growing long, grassy leaves as well as hanging stems, which eventually sprout plantlets—hence its arachnid-inspired name. Place a spider plant on a pedestal or in a hanging basket close to a sunlit window and you’ll benefit from fewer airborne formaldehyde and benzene molecules.

Rubber Plants & Janet Craigs

If you’ve got a dim office that’s just screaming for cleaner air and a little touch of nature, try a rubber plant or Janet Craig. Both will tolerate very little sun—although they may grow more slowly—and are at the top of the list for formaldehyde removers, which is particularly important in office where most furniture is made from particleboard held together by formaldehyde-based glues. Janet Craigs will tolerate more abuse and neglect than rubber trees, but rubber trees are more aesthetically pleasing.

Peace Lily

Among the few air purifiers that flower, the peace lily adapts well to low light but requires weekly watering and is poisonous to pets and children. This year-round bloomer rids the air of the VOC benzene, a carcinogen found in paints, furniture wax, and polishes. It also sucks up acetone, which is emitted by electronics, adhesives, and certain cleaners.

Golden Pothos

Though not high on the list of formaldehyde removers, this plant is a tough one to kill. It tolerates a lot of neglect, is forgiving when over-watered, is relatively effective at removing many air pollutants, and is a great starter houseplant for people without much indoor-gardening experience. Golden Pothos are often mistakenly sold as philodendrons, which are related plants that are equally good at removing formaldehyde and are almost as forgiving to newbie houseplant tenders. For the best results, put as many plants as you can care for in the rooms you use most. That means you’ll want at least two plants (in 10-to-12-inch pots) per 100 square feet of space; if you’re in the middle of major renovations, aim for more plants. One tip: Be sure not to overwater, as too much soil moisture can lead to mold growth.