A lot of essential oils are effective fungicides. It’s no surprise since the plants need to protect themselves from fungi all around them.
You could mix up the oils yourself, but having a calculated mix of oils in a blend can help it kill a wider variety of molds.
You can mix the oil blends into a liquid cleaner or use the products that come pre-mixed in a surfactant to kill mold on hard and porous surfaces in the home. You can also fog to kill mold spores in the air.
We will go over all of these methods in detail.
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Essential Oils That Kill Mold
1. Fir Oil
Essential oil from Pinus sibirica (Siberian pine) and Аbies sibirica (Siberian fir) are effective against Candida albicans(source).
2. Lemon Oil
Citrus limon (lemon) essential oil showed inhibitory anti-fungal activity against Aspergillus flavus, Fusarium spp., Aspergillus niger (source), Aspergillus parasiticus, Cladosporium cladosporioides, Eurotium herbariorum, Penicillium chrysogenum, Aspergillus carbonarius (source) and Penicillium verrucosum(source).
Similar: Other citrus oils like mandarin (Citrus reticulata L.), grapefruit (Citrus paradisi L.) and orange (Citrus sinensis L.) showed anti-fungal activity against the molds Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum and Penicillium verrucosum (source).
3. Cinnamon Oil
Cinnamon oil proved to be a potent fungitoxicant against: Aspergillus niger, Aspergillus fumigatus, Aspergillus nidulans, Aspergillus flavus, Candida albicans, Candida tropicalis, Candida pseudotropicalis (Candida kefyr), Histoplasma capsulatum (source), Coriolus versicolor, Laetiporus sulphureus (Source), Eurotium spp., Aspergillus spp., Penicillium spp. (source), and Botrytis cinerea (source).
4. Rosemary Oil
Rosemary essential oil exhibited anti-fungal activity against Eurotium spp., Aspergillus spp. and Penicillium spp. (source). Other studies show Rosemary’s anti-fungal activity (source).
5. Clove Oil
Clove essential oil exhibited anti-fungal activity against Eurotium spp., Aspergillus spp., Penicillium spp (Source), and Botrytis cinerea (source).
6. Copaiba Oil
Copaiba oil displays anti-microbial action against fungi, such as Candida spp (source and source), Candida parapsilosis, Aspergillus flavus, and A tamarii (source).
7. Tea Tree Oil
Tea Tree Oil is effective against Candida albicans, as well as a range of yeasts, dermatophytes, and other filamentous fungi (source).
8. Eucalyptus
Eucalyptus is a potent antifungal agent against C. albicans and its biofilm (source) and Penicillium funiculosum, Aspergillus niger and Aspergillus flavus (source).
9. Thyme
Thyme oil exhibited antifungal properties against Aspergillus spp, such as A. flavus, A. ochraceus and Fusarium spp, for example F. oxysporum, Candida spp, for example Candida albicans and Candida tropicalis, Penicillium spp and Cladosporium spp, Botrytis cinerea, Alternaria brassicae, and Dermatophytes (source and source).
*Please note that spp means multiple species.
Essential Oil Blends That are Anti-Fungal
Germ Fighter by Plant Therapy – Cinnamon Cassia, Lemon, Eucalyptus, Clove, Rosemary. This is a well-priced non-MLM brand that is high-quality and legit (they produce GC-MS testing by several third-party laboratories).
On Guard by doTerra – Wild Orange Peel, Clove Bud, Cinnamon Leaf, Cinnamon Bark, Eucalyptus Leaf, and Rosemary Leaf/Flower.
Thieves Oil by Young Living – Clove bud oil, Lemon peel oil, Cinnamon bark oil, Eucalyptus leaf oil, Rosemary leaf oil.
Diffusing/Fogging Essential Oils to Kill Mold in The Air
Diffusing/nebulizing essential oils is the best way to deploy them to kill mold spores in a building. I would do this when people and pets are out of the room because diffusing creates high levels of VOCs and PM2.5 particulates.
Fogging to Kill Mold Spores
Dr. Edward R. Close, PhD in Environmental Engineering, diffused Thieves Oil blend (a blend of Clove (Syzygium aromaticum) bud oil, Lemon (Citrus limon) peel oil, Cinnamon (Cinnamomum verum) bark oil, Eucalyptus (Eucalyptus radiata) leaf oil, and Rosemary (Rosmarinus officinalis) leaf oil) in the Aroma-Ace Atomizing Diffuser in homes for a 24-hour period.
(You could also use the mix by Plant Therapy, which is made with the same plants but is less expensive).
Dr. Close and his wife, Jacquelyn Close, discovered that diffusing essential oils with a waterless cold air nebulizer was the best solution to address mold spores in buildings. The results of their case studies showed a huge reduction in mold spores and it had residual effect (i.e. the spores did not come back quickly).
His research showed that the essential oils digest the mold spores that they come in contact with and don’t leave dead mold spores behind.
NOTE! If you have mold growing in the wall this does not address that underlying problem and the mycotoxins and mold VOCs being produced. Putting a bandaid on the situation could cause a false sense of security.
They recommend that you place one diffuser in each room (one for every 1000 sq ft) and diffuse continuously for a minimum of 24 hours. How long you have to diffuse (24-48 hours or longer) is determined by air sampling or tape-lift sampling. Use a glass plate under the diffuser to protect surfaces from the oil.
This book by Dr Close and his wife goes into more detail.
If you prefer to watch a seminar about Dr Close’s methods, this masterclass will be helpful. He is talking with mold-preventative architect Cheryl Ciecko. The other classes in the series will also be helpful in making sure you properly identify the source of the mold and safely clean mold (as you could do a lot of harm cleaning it yourself). Don’t just put a bandaid over it!
Cleaning Surface Mold With Essential Oils
“The surface mold is usually being caused by moisture and mold spores somewhere else that is causing the ‘surface mold’ to appear in the first place. If the surface is porous (wood, drywall, grout, brick, concrete or other materials) then cleaning the surface mold can be like cutting down a plant while leaving the roots below the surface. The plant and the mold will grow back.” says Cheryl Ciecko, mold preventative architect.
Make sure you have identified the source of the problem, corrected the problem, dried out the area. Many moldy materials need to be totally removed – like moldy drywall and most moldy wood. But if you truly have a superficial mold problem you can clean it with essential oil based cleaners then dry out the area again with dehumifdifiers, says Cheryl Ciecko.
Cleaners for mold on surfaces:
Thieves Cleaner – is made with Clove bud oil, Lemon peel oil, Cinnamon bark oil, Eucalyptus leaf oil, Rosemary leaf oil and surfactants.
Benefect Decon 30 is an EPA approved fungicide. The product’s active ingredient is natural Thymol (from Thyme) which kills Trichophyton Mentagrophytes which is the representative organism over the entire category of mold/fungi/yeast; ie, the hardest to kill as per the EPA. It is also effective against Candida Albicans and Aspergillus Niger.
Cleaning Mold Off Concrete With Essential Oils
Make sure you diagnose the cause, and correct the problem first says Cheryl. Next up make sure to dry out the concrete before cleaning (if it’s interior concrete, like basement walls).
To clean use diluted Thieves Cleaner with a scrub brush. You can see Dr Close show his experiment with a moldy patio in Cheryl’s recorded webinar with him (I do consider this webinar series essential if you want to learn how to safely clean mold yourself).
You can also use Benefect Decon 30. Wet the surface by sprayer (high or low pressure, hand or power operated), cloth, sponge or mop. Leave for 10 minutes. Allow to air-dry. No rinsing or wiping is required.
Make sure you’re using PPE (respirator, goggles, Tyvek suites). You may want to use a HEPA vacuum as well first to pick up spores.
Dry again after cleaning using dehumidifiers (for indoor concrete).
Cleaning Mold Off Wood With Essential Oils
Make sure you have identified the source of the problem and corrected it. Moldy wood usually needs to be wet sanded or removed. Test it with a moisture meter to make sure the problem is resolved. Remember that structural wood needs to be evaluated by an engineer before removing it (that includes small areas of subfloors).
If you have superficial mold on wood, or after you have sanded it, Cheryl Ciecko recommends scrubbing with a stiff scrub brush using Thieves cleaner only slightly diluted or undiluted to not add much water. Then dry the area well.
The Thieves cleaner will result in some color changes to the wood (as do all essential oils in my experience).
You can also use Benefect Decon 30. Wet the surface by sprayer (high or low pressure, hand or power operated), cloth, sponge or mop. Leave for 10 minutes. Allow to air-dry. No rinsing or wiping is required.
Use protection for yourself (respirator, goggles, Tyvek suites) and a HEPA vacuum as well to clean up spores.
Cleaning Mold Off Drywall Walls With Essential Oils
Cheryl Ciecko cautions cleaning mold off drywall. Mold on drywall is often a sign of water damage behind it and if mold is in the paper layers or the gypsum layer it must be removed she says.
It is possible that you have superficial mold growing only on top of the paint. You still need to correct the source of this problem which is high humidity.
But you can clean mold off the paint with a gentle all purpose cleaner, Thieves Oil cleaner or Benefect Decon 30 (Benefect needs a dwell time of 10 minutes).
Cleaning Mold Off Shower Walls and Grout With Essential Oils
Two things to note first about mold in showers/grout. Mold is grout is very common but not “normal”. Cheryl says about her well built shower that she never has mold in the shower area. Mold in grout is often a sign that there is mold behind the grout/tiles.
Keep in mind that the grout is not the water protection layer, there is a layer behind the mortar for water control (which is so often done wrong). Use a moisture meter to test your tiles/grout for possible water damage behind. Grout doesn’t need to be sealed to prevent mold and you don’t need this to be your water control area. You can use a breathable grout sealer, outlined here, which makes it a little easier to clean.
Make sure to keep soap scum off the grout by regularly cleaning it and make sure your exhaust fan is adequate to dry out the room during and after each shower and bath.
You can clean your grout with Thieves oil cleaner, or Benefect Decon 30 (with a dwell time of 10 minutes). You can use hydrogen peroxide with baking soda (mixed together) to remove the leftover mold stains. (Don’t mix essential oils with hydrogen peroxide).
Cleaning Mold Off Soft Items
Using Essential Oils in Laundry to Kill Mold
Those who are extremely sensitive to mold that gets on clothing from the home or workplace use a variety of methods to clean laundry. There isn’t one solution that works best on all molds.
The most popular non essential oil products are borax, ammonia and TSP (separate, not all together!)
Essential oil based cleaning products for laundry that folks like include:
- EC3 laundry Additive – is made from Citrus Seed extracts, Tea Tree oil, and natural surfactants.
- Thieves Oil Laundry Soap – contains Clove bud oil, Lemon peel oil, Cinnamon bark oil, Eucalyptus leaf oil, Rosemary leaf oil, Jade Lemon, and Bergamot essential oils, enzyme cleaners, and surfactants.
- On Guard Laundry Detergent -contains Wild Orange Peel, Clove Bud, Cinnamon Leaf, Cinnamon Bark, Eucalyptus Leaf, and Rosemary Leaf/Flower essential oils, surfactants, and enzymes.
- Or add essential oils of your choice to your unscented liquid laundry detergent and mix together before adding it to the wash.
Using Essential Oils to Kill Mold on Carpet
For carpet in a car Cheryl Ciecko recommends using diluted Thieves cleaner to clean and scrub, then blot out moisture with towels moving on to using paper towels until no more moisture comes out.
It terms of carpet in a house that is a different story. It depends on where the mold is and how it got there. If you have moisture rising from below then you need to remove the carpet. If a flood caused major mold then I would remove it as well.
If the problem is smaller or more superficial, then you can first HEPA vacuum and then fog essential oils as described in the above section on fogging. You may need to do this every 3 months says Dr Close.
Cheryl Ciecko believes that shampooing is not a good ideas as it adds water which will feed mold spores.
If you do want to shampoo your carpet Benefect Decon 30 is an EPA approved carpet sanitizer. Apply to the pre-cleaned carpet area by wand, sprayer, extractor, spin bonnet or immersion processes until saturated (spot test fibers for colorfastness before use). Scrub or agitate the carpet as needed to ensure the test substance is delivered throughout the carpet pile and backing. Allow the product to remain on the carpet undisturbed for a minimum of 60 minutes. Extract & allow to air-dry. (Use a dehumidifier after if your humidity is not low).
Can You Mix Essential Oils With Other Cleaning Products?
You can mix essential oils into vinegar, or a liquid soap. Mixing essential oils and hydrogen peroxide produces a strange oxidized odor in my experience, so I would not mix those myself.
Corinne Segura is a Building Biologist Practitioner with 8 years of experience helping others create healthy homes.