The best house plants to keep your home fresh - At the end of the 1980s, NASA and the Associated Landscape Contractors of America did a study on several plants to discover which were the best at purifying air. The idea was to be able to use the best ones in space installations.

They identified several plant species that were able to filter chemicals and other toxic elements from the air.

The American Society for Horticultural Science later expanded on the topic and defined which are the best plants for people to keep at home - check them out!

© iStock

Aloe Vera - Aloe Vera is an easy-growing plant that loves sunlight. It can help clean the air in your house, leaving it free from formaldehyde and benzene, toxic agents found in chemical cleaning products and paint.

© iStock

Aloe Vera - This is a great plant to keep in the kitchen, next to a sunny window. As well as its air purification abilities, its gel is great for treating cuts and burns, according to the U.S. Department of Health and Human Services.

© iStock

Gerbera - Gerberas are great for cleaning the air from trichloroethylene, a chemical that can get into your house through dry cleaning. The plant also removes benzene from the atmosphere.

© iStock

Gerbera - Put Geberas in bedrooms or laundry rooms, in a spot where they can get a lot of light. This plant needs at least six hours of sunlight a day!

© iStock

Spider plant - Spider plants are great if you want something that doesn't need a lot of care. These plants can help combat toxic elements in your home such as benzene, carbon monoxide, xylene, and formaldehyde.

© iStock

Spider plant - As well as being safe for those with pets living at home, these plants are also easy to grow in mild temperatures. They grow better out of direct sunlight.

© iStock

Viper's bowstring - Also known as Mother-in-law’s Tongue, Snake Plant, and Goldband Sansevieria, this plant is brilliant for ridding your home of formaldehyde, which can be found in various cleaning products, toilet roll and other fabrics.

© iStock

Viper's bowstring - These plants need dark and humid conditions, so the bathroom is probably the best room to keep them in. Putting them in your bedroom could also be a good option, as they give out oxygen at night.

© iStock

Devil's ivy - Also known as Golden Pothos, this is another species that fights formaldehyde in the air. It grows quite quickly, which is why it's common to see this plant with a 'cascade' of leaves falling over one side of its pot.

© iStock

Devil's ivy - Keeping this plant in the garage is recommended, as it absorbs the formaldehyde found in exhaust fumes, but make sure to keep it away from children and animals as it is poisonous. Devil's ivy survives well in the dark, and only needs indirect sunlight.

© iStock

Chrysanthemum - As well as brightening up any room, this plant is one of the best for purifying the air from chemicals such as benzene. It needs a lot of sunlight, so be sure to keep it in a sunny spot.

© iStock

Chrysanthemum - Make sure you choose floral chrysanthemums that thrive indoors, as opposed to outdoor varieties. They come in pretty much all colors, so you'll be able to choose the ones that go best with your interiors!

© iStock

Dragon tree - The red-edged leaves of this plant can grow until they reach the ceiling! Dragon trees are great for filtering xylene, trichloroethylene, and formaldehyde from the air, chemical agents found in lacquers, varnishes and petrol.

© iStock

Dragon tree - There are several varieties of this species, but almost all of them look the same. This specific one grows slowly, and thrives in spaces with high ceilings and moderate levels of sunlight.

© iStock

Weeping fig - The weeping fig may not be an easy plant to look after, but it's worth it as it helps to target chemicals found in the air, such as formaldehyde, benzene, and trichloroethylene.

© iStock

Weeping fig - Consistency is key if you want this plant to grow well. It needs indirect sunlight and constant, regular temperatures.

© iStock

Ivy - It has been scientifically proven that this plant filters particles of fecal matter from the air, and also formaldehyde. Even though it's aggressive to other plants in its vicinity, it's great to have in your home.

© iStock

Ivy - When kept in a pot, ivy is not such a threatening plant. It needs constantly humid soil and about four hours of direct sunlight a day.

© iStock

Azalea - Azaleas help clean the air in your home from formaldehyde. They grow best in colder places, with some sunlight.

© iStock

Azalea - Azaleas are great for humidifying your house, but make sure you don't let dead leaves stay in the pot, as this makes the plant more prone to spreading illnesses.

© iStock

Dracaena - Dracaena filters out air pollutants that come from varnishes and other types of oils. It grows easily indoors, even without direct sunlight.

© iStock

Dracaena - This type of Dracaena typically has long white bands running along its leaves. If its tips start to turn brown, this means the water it's getting has too much fluoride in it.

© iStock

Chinese evergreens - This plant continually filters out pollutants from the air throughout its life. As it keeps growing, it gets better and better at this.

© iStock

Chinese evergreens - This is one of the easiest plants to keep at home. It thrives with little light and can grow where other plants never can. As it is a tropical species, it is used to humid conditions.

© iStock

Areca palm - This plant is one of the best benzene and trichloroethylene filters you can have in your house.
It is also a good option for keeping near new furniture painted with varnish, which could be releasing formaldehyde into the air.

© iStock

Areca palm - This palm prefers humidity and indirect sunlight. It doesn't grow well in overly hot conditions, and it can grow up to two meters high.

© iStock

Heart-Leaf Philodendron - Remember that this plant is poisonous, so keep it away from kids and animals. But apart from this, it is extremely good at removing formaldehyde from the air.

© iStock

Heart-Leaf Philodendron - This plant doesn't need much looking after, just some indirect sunlight.

© iStock

Peace lily - This lily just needs shade and to be watered weekly to survive. It is one of the most used plants by NASA owing to its extreme efficiency in cleaning the air from formaldehyde, benzene, and trichloroethylene, as well as toluene and xylene.

© iStock

Peace lily - It's a very easy plant to look after and goes well in any part of the house. It is easy to tell when it needs water as it will droop!

© iStock