Do Oil Diffusers Leave Residue?

Oil diffusers are the easiest and quickest way to disperse essential oils into the air and have become quite popular since they entered the aromatherapy scene. Manufacturers put labels on their products boasting how efficient they are and attracting new buyers by the day. However, Are they? Do oil diffusers leave behind a residue?

Oil diffusers leave a residue when they are not cleaned regularly or when you use low-quality essential oils. Diffusers cannot completely vaporize some viscous and impure oils, which will leave oil deposits in your diffuser, and at times, an oily film on the nearby walls and furniture.

The only way to avoid residue on your oil diffuser is by purchasing quality diffusers, essential oils, and cleaning your diffuser regularly. Continue reading to discover why oil diffusers leave a residue and learn more about how to avoid this scenario.

Do Oil Diffusers Leave Residue

Why Oil Diffusers Leave Residue

Have you ever wanted to relax after work by diffusing lavender essential oil, thinking it will calm the tension in your nerves? Only to get a faint scent of lavender mixed with a more pungent energizing grapefruit scent you diffused earlier before you went to work?

Also, it may not have occurred to you as yet, but it is possible to find a gummy residue of fragrance oils on the plate of your nebulizer. This is how the phenomenon comes about.

Nebulizing Viscous Oils

Cleaning empty essential oil bottles for reuse is quite a hectic process. The gum-like leftovers refuse to let go of the bottle even after multiple cleaning with detergents and boiling water. The same scenario applies to your diffuser but on a lower scale.

A nebulizer uses high-frequency sound waves to break down fragrance or essential oils into small particles, which disperse into the air. One downside of a nebulizer is that it cannot atomize viscous oils such as sandalwood, patchouli, and vetiver. The result is an oily sticky deposit left behind in the nebulizer and a tank in need of deep cleaning.

Adulterated Diffusing Oils

Pure and natural essential oils are costly due to the tons of materials used and the extraction process cost. Many people shy away from buying them at their original prices. Therefore, unscrupulous dealers result in the uncouth practice of degrading the natural oils to make more sales by selling not so pure oils at a lower cost.

Adulteration means mixing pure essence natural oil with alcohol, fatty oils, and carrier oils. This decreases the quality of the diffusing oils. The diffuser will diffuse essential oils first since they are volatile and are not fatty. Fatty oils contain lipids and take a longer time to evaporate and are left behind as residue.

The small number of fatty oils that evaporate will condense and settle on the diffuser’s outer walls. The greasy residue will, if left unattended, clog not only the diffuser but also stain furniture, curtains, bare painted walls, and other household items.

Added Colors

Colors are attractive to the eye and appeal to human feelings. Some manufacturers of essential oil may use colors as a selling technique. For example, they will add a purple color to grapefruit essential oil to distinguish from other oil types. Quite clever.

These colors lack the volatility of the accompanying essential oil and are consequently left behind as a residue when the essential oil diffusers. An essential oil that contains large amounts of monoterpenes or oxides or tea-tree extracts will evaporate quickly depending on how fast air is circulating in the room or room temperature and leave the color as residue.

Use of Heat To Diffuse Essential Oils

The earliest form of a diffuser and the most common diffusers use heat to vaporize essential oils. The ultrasonic diffuser and the nebulizer do not use heat to diffuse essential oils, making the perfect diffusers if you want to avoid residue.

Heat alters the chemical composition of essential and fragrance oils. While it causes some oils to diffuse faster than required, it may cause some oils to become dense and gummy, which will not evaporate but stick to the bottom of the heating system. Generally, you cannot avoid your diffuser leaving a residue since almost every diffuser available in the market uses heat to breakdown essential oils.

While some brands produce efficient diffusers, other brands leave a residue, mainly if you use them continually for some time.

How Does Residue Left Behind After Diffusion Affect You?

Residue in a diffuser is an unwanted guest. For the most part, it will bear harmful fruits. Here are some of the effects the residue will have on the diffuser and the household.

Oil Residue Will Interfere With Service Delivery and Bring High Maintenance Costs

The typical diffuser uses a heat source to vaporize essential oils. The residue will stick to the heating parts. The diffuser will have to use more heat than usual for subsequent diffusions. Most likely, it may overheat and, in extreme cases, stop functioning altogether.

Broken down diffusers are bad news. They will deny you your favorite aromatherapy session as well as increase the maintenance cost. You will have to bear replacement costs in case the diffuser if your diffuser is beyond repair. Quite costly.

Oil Residue Will Stain Your Furniture and Other Accessories

As earlier stated, synthetic dyes are blended with essential oils to make them attractive. These dyes will not only negatively affect your health when breathed in but will also settle on your furniture.

Residue stains will land on the diffuser and items nearby, such as carpets, curtains, paintings, and even stain the white papers on your work desk. Just imagine your dear Da Vinci painting looking like a Picasso!

It would be best if you remembered at this point that some essential or fragrance oils are adulterated and sold to ignorant consumers at a lower price. In some cases, some essential oils get infused with impurities such as alcohol and vegetable oil. Ignorance, in such a case, is costly.

Vegetable oil contains lipids, which explains its oily, fatty nature. The bad news is that it will clog your diffuser as well as settle on your household items. You will spend precious time and resources buying several cleaning products, wiping and scrubbing. Quite laborious.

Safety Tips When Using a Diffuser

After diffusion, the residue left behind has the potential to wreak havoc on the floor, furniture finishings, paintings, wallpapers, and your workspace. Safety concerns are your priority at this point. These tips should help you.

Ensure You Buy High-Quality Diffusing Oils

Cheap is always expensive in most instances. Low-cost diffusing oils will be costly on your diffuser, health, and the household. Take care to buy oils from certified sellers and reputable stores that you trust. Always pick high-quality diffusers that your diffuser can accommodate. 

Place the Diffuser Below Your Eye Level

The truth is that the higher you will place the diffuser, the larger the area the mist will get. Diffusion mist coming from your eye height will spread a smaller distance; therefore, affecting fewer items.

You Should Not Diffuse Near the Walls

When your diffuser stains your walls, rubbing off the residue may make the paint peel off, leaving behind ugly patches. You surely don’t want that.

It is also common practice to place your paintings and wallpapers on the walls. The oily mist will ruin the paintings as well as peel the wallpapers.

Diffuse in the Bathroom Whenever Possible

Interior designers use ceramic tiles to finish the bathrooms’ walls and floors because they are easy to clean. In case of any residue or essential oil spill, you will comfortably clean the spot as you wash the bathroom. The bathroom is also secluded from the public eye in case of stubborn stains.

How to Clean your Diffuser

Hygiene is your biggest weapon against residues and stains left behind on the inside walls of the diffuser. You are probably wondering what the best way to correctly and adequately get rid of that oily and sticky substance on the ultrasonic diffuser plate is. How do you clean your diffuser?

Experts, consultants, and manufacturers recommend cleaning the unit after every use or when you hop from one scent to another. If you diffuse daily, cleaning twice a month is recommended. Cleaning the device intensely once a month will remove the dust accumulated over the month and oil residue.

Don’t forget to properly clean the ultrasonic chip or plate as it is responsible for breaking down the oils into smaller molecules through vibrations at high ultrasonic frequencies. Leaving the plate dirty will result in low diffusion or even total breakdown. The following steps will help you routinely clean essential oil diffusers.

Unplug From the Power Outlet

Switch off the diffuser and carefully unplug the power cable from the socket, extension cables, or any other power source you may be using. It will keep you safe from an electric shock while cleaning.

Empty the Tank

Pour out the oil-water mixture in the case of an ultrasonic diffuser. Emptying the tank will give you easy access to the residue at the bottom of the tank.

Clean the Tank

Place a small amount of liquid dishwashing soap on a microfiber cloth and wet it. Gently wipe or scrub the sides of the reservoir with the soapy cloth. Rinse with fresh warm water—dry using a clean microfiber cloth.

Use Solvents to Clean Stubborn Oily Residue

Dip a cotton swab in an alcohol-based solvent such as isopropyl. Use it to clean the ultrasonic plate of your diffuser and eliminate any oily residue.


The final step is to reassemble the diffuser. Connect different parts of the diffuser as directed on the manufacturers’ labels. Refill with oils or water-oil mixture for ultrasonic diffusers before using.

Avoid Low-Quality Oils and Clean Your Diffuser Regularly

Many recognized brands advertise that their diffusers do not leave residue behind. However, even the most efficient diffuser will leave a residue if you don’t take all the precautions. 

Importantly, low-quality essential oils are responsible for the deposition in most cases. Viscous and adulterated oils contain impurities that form a residue. Therefore, you make sure to buy quality oils for your diffuser and clean it regularly.

Use ordinary liquid soap to clean stains on the diffuser reservoir before a refill, as this will help you enjoy your diffuser without having to worry about residue.

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Grace Young

I love candles! I have personally tried over 100 brands of candles. The total burn time of these candles is over 5000 hours. I also talk about essential oil diffusers and reed diffusers. Essential oil diffusers and diffusers are also an important part of the scent in my home.

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