Dr. Bronner's

Dust Mites and Castile Soap

Eeew. To me that’s a pretty icky word in the title there. Dust Mites are something I don’t like to think about, especially not in the context of their residence in my house. However, just slightly below them in my grossness hierarchy is the dust itself. One reason to keep up with regular cleaning is to reduce the presence of dust mites in my house. The idea that dust causes people to sneeze is somewhat valid, but what is of greater concern – and potentially dangerous to asthmatics – are the dust mites which feed on the dust.

I always equated dust with dirt – very fine dirt. I figured we have a lot of it because we have five people and two dogs tracking in dirt from the outside. While there certainly is some dirt in my household’s dust, it’s not at the top of the list. A variety of sources agreed on what this article from Time magazine summed up:

Nearly everywhere, dust consists of some combination of shed bits of human skin, animal fur, decomposing insects, food debris, lint and organic fibers from clothes, bedding and other fabrics, tracked-in soil, soot, particulate matter from smoking and cooking, and, disturbingly, lead, arsenic and even DDT. (Here’s more on that.)

So let me say it again: Eeeeewww!
And dust mites find this medley quite tasty. So where there is dust, there are dust mites. Just to lay it all on the table, the exoskeletons and poop from the dust mites cause an immune system response in sensitive individuals. (Although, I would imagine that inhaling any bug – technically an arachnid here – would be problematic.)

The best habitat for dust mites are carpets and bedding. Such places are sheltered and cozy with lots of nooks for dust and lots of opportunities to snag skin particles, animal fur, lint, and the rest of that list above. In regards to human breathing, however, the bedding is the main concern. By in large, unusual circumstances notwithstanding, we spend more time lying in our beds than we do on our carpets. Fortunately for us, it’s easier to wash our bedding than our carpets.

Here’s where the Castile Soap enters in
As I’ve covered earlier in regards to spraying for ants, Castile Soap dissolves exoskeletons. So, when it comes to treating for dust mites, this particular attribute of Castile Soap once again comes in handy. I use Sal Suds for my everyday laundry – it is slightly better at whitening whites and getting rid of stains. However, for my bedding, I reach for Dr. Bronner’s Liquid Castile Soap – usually the Peppermint, but any one of them will be effective.

Heat also kills dust mites, so with the combo of heat and Castile Soap, there’s really little chance for survival. Bedding should be washed frequently because new mites take up residence regularly. Also, the combo of high heat and frequent washings can take a toll on fabrics, so opt for 100% cotton fabrics with a moderately high thread count (300+).

The recipe*:

  • 1/3 c. (80 mL) Castile liquid soap
  • 1 c. (240 mL) vinegar
  • Hot water
  • Hot dryer
  • If you have an HE machine, cut each of the measurements by half.

Add the Castile soap to the bedding in the washer. Set the washer at the hottest setting. Put vinegar in the fabric softener cup, so that it will be added during the rinse cycle. (Castile soap can leave a residue on fabrics washed in hard water. Vinegar eliminates this residue.) Dry the bedding on the hottest setting.

For my laundry routine, see my post, Green Laundry Care with Dr. Bronners

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Lorraine says:

What if you have a water softener which uses much less product? Do advise amount to use.
Thank you,
Love this product

Lisa Bronner says:

Hi Lorraine- Although there is some soap tied up by the minerals in hard water, there is not a significant amount that would result in using a different measurement of Castile Soap.

KathyS says:

Dear Lisa,

In your article about washing sheets, you mentioned that any one of your castile soaps will kill the dust mites. Does that mean that any one of your castile soaps will also kill demodex skin mites? I was under the impression that only Tea Tree would kill them.

Lisa Bronner says:

Hi Kathy- I’m so sorry, I don’t have any information on this type of skin mite.

Stephanie Rojas says:

Hi I have the 18 in 1 almond and was wondering if it can be used in a carpet cleaning machine and if youd have a recipe for it. It’s my first time using it and I’m a little overwhelmed on how to use it

Alison says:

You mentioned to add 240ml of Vinegar to the washing.
Where do you add it to in a front loader machine. Our washing machine has three compartments for the detergent dispenser. (Pre-wash, Wash & Softener)
Which one do I add it to?

Lisa Bronner says:

Hi Alison- Add the vinegar to softener compartment, where it will be dispensed into the rinse cycle.

Catherine says:

Does the castile soap still work on mites if you don’t use a dryer? I hang my clothes etc on a drying rack.

Lisa Bronner says:

Hi Catherine- Castile soap and hot water are a good duo for getting rid of dust mites. Air drying clothing does save on energy and is easier on fabrics, but the heat of the dryer will add another layer of eliminating dust mites, so you’ll want to take that into consideration.

chiara says:

hi, can I still dry my bedsheet without a dryer, and have a good result? Thanks!

Lisa Bronner says:

Hi Chiara- Castile soap and hot water together are an effective combo for getting rid of dust mites. Line drying does save on energy and is easier on fabrics, but the heat of the dryer adds another layer of eliminating dust mites, so you’ll want to take that into consideration.

Judy Schorer says:

I have had some Castile soap for quite a while. I just couldn’t figure out how to use it. The bottle is very confusing as far as dilution. I finally have taken the time to look it up. However, I am wondering if my soap is too old. How can I tell?

Lisa Bronner says:

Hi Judy- Our products have a guaranteed shelf life of 3 years. After this time, essential oils in the soap may begin to lose the potency/strength and smell weaker, but will still be effective cleaners. The manufacture date is etched on the packaging, just below the label. The first four numbers there are the Julian date. You can look that up, or if you share with me I’ll check. The Castile soap has so many uses! If you haven’t already found our cheat sheet, it’s very handy:

Patricia Cooper says:

Never thought dust was that gross!
Lots of pets
Equals Dust

Lisa Bronner says:

Hi Cindy – For surface cleaning a mattress, I use one of my All Purpose Sprays – either 1 Tbsp of Sal Suds in a quart of water or 1/4 cup of Castile. I spray the mattress lightly and wipe with a damp cloth. Allow to air dry fully. The key is to be sure not to have moisture soak into the mattress where it might not dry and may mold. Another option is to spray the damp cloth with the a bit of the All Purpose Spray and then wipe the mattress.

Terry says:

I steam my mattress a couple times a year. I use my garment steamer, but I before I had one, I used to use my steam iron and a damp towel. Steam kills the dust mites, and denatures the proteins that cause the allergic reaction. 🙂

Cynthia says:

I’m wondering if you can use the same sal suds recipe for cleaning a down comforter. All the references I’ve found for home cleaning just say to use a mild soap.

Lisa Bronner says:

Hi Cynthia- Sal Suds is mild enough for down, as long as the comforter is washable. Use 2-3 Tbsp. Sal Suds for a top loading washing machine or half that for an HE machine.

Cynthia says:

It worked great! I took it to the laundromat and used the extra large washer and dryer – for my queen size down comforter, I used 3 Tbs of Sal Suds and 1 cup white vinegar in the softener dispenser and did a double rinse. It’s clean and fluffy and mite free. Thank you!

Roz behan says:

I’d like to make sure Dr. Bronner’s with my laundry recipe using baking soda and washing soda and essential oil is that more affective? I can’t wash my sheets as they would shrink. I also and peroxide and vinegar in the rinse.

I I love your products

Lisa Bronner says:

Hi Roz- Its great to hear you love our soaps! Baking soda and washing soda serve the same purpose in your laundry, so you don’t need both. Washing soda is the stronger of the two, so save that for really grungy loads. If used often, it can wear down fabrics. Essential oils are probably unnecessary since the soap will latch onto the oils and wash them away. Vinegar in the rinse cycle is a great natural fabric softener and deodorizer all on its own. I’ve just updated my laundry video, which you might find helpful:

Laurie says:

Re vinegar: I have used white vinegar in the rinse cycle for years. A repairman recommended it. It allows for more thorough rinsing so that clothes dry naturally softer. I never use dryer sheets. As a bonus, he also said it extends the life of your washer because it eliminates soap buildup internally. A win-win.

Lisa Bronner says:

Excellent! Thanks for sharing, Laurie!

RD Wolff says:

Commercial dryer sheets for softness and static do it by coating your clothes with chemicals, this stuff also winds up on the dryer heating elements, I never use the stuff.

Dilutions Cheat Sheet for Dr. Bronner's Castile Soap says:

[…] Dust Mites and Castile Soap […]

Ana says:

Can you use the soap for hand washing laundry? Or is it for machine washes only?

My Cleaning Cabinet says:

[…] A quart of Dr. Bronner’s Liquid Peppermint Pure Castile Soap – Most often I add it to washing sheets and spraying for […]

Sal Suds or Castile Soap - Which One Should You Use? says:

[…] You’ll only notice this on shiny objects that are left to air dry.  They will take on a whitish film. (Read my post on eliminating soap scum.) Also, absorbent fabrics like towels and cloth diapers will become stiff and lose their absorbency. (But laundry in hard water is still doable – Read more here.) […]

peter meier says:

Interesting, but just one laundry with 1/3 c (79ml) would cost round about 5€ (5.9$), only for the soap. Incredible expensive and sadly nothing for the all-time use.

Lisa Bronner says:

Hi Peter – For our everyday laundry, I use the Sal Suds as it’s slightly better at whitening whites and getting out stains. It’s more concentrated than the Castile soap and a little bit goes a long way. It’s just 1T Sal Suds (15ml) for an HE washing machine or 2-3T for a top-loading machine. Here’s my post about laundry with Sal Suds:

Using Soap to Test for Hard Water (Video) says:

[…] Add ½ to 1 cup of vinegar to your rinse […]

Tara says:

Hi Lisa! Thanks for this post. I suffer from allergies, asthma and a disorder called Mast Cell Activation Disorder (sometimes referred to as syndrome or disease.) Which is sort of like I’m allergic to everything (or so it seems!) Pk my question: when you say add the Castile to the bedding in the washer…. my machine has a spot for soap that dispenses it itself, is this ok or do you mean I should manually add it? Thank you again!!! You’re such a blessing.

Lisa Bronner says:

Hi Tara – Yes, just add it to the detergent dispenser in your washer. Our Baby Unscented Castile is often good for people with allergies and sensitive skin.

Sharon Agoston says:

Everyone here speaks alot about laundry and Castile soap.
I want some deeper information.
Lets say disinfectant properties for castille soaps for athletes foot in socks on bedding and virus’s even for cold water fabrics. Which Dr. Bronner’s products eliminate or disinfect under these conditions.

Lisa Bronner says:

Hi Sharon – Great questions. It isn’t often that soap makes the national headlines, but we were quite excited when it did 2 years ago. The FDA (which is notorious for its inaction as far as personal care products go) had looked into the efficacy of “antibacterial” products and found that they are no more effective at eliminating germs and stopping the spread of disease than regular soap and water. Here’s their article:, and the most succinct quote from it is, “manufacturers haven’t shown that these ingredients are any more effective than plain soap and water in preventing illnesses and the spread of certain infections.” Although this article is addressing products used on people, the issue is the same. If soap and water are effective at removing germs and stopping the spread of illness on our bodies, they are going to do the same on other surfaces.

Regarding the temperature of water, the CDC came out with a ruling on that one saying, “The temperature of the water does not appear to affect microbe removal.” From this article:

To sum up, the soap will work great at eliminating microbes of all sorts, even in cold water.

Patty says:

What about the recipes for clothes detergents that use a small amount of Castile soap, washing soda, and/or borax, and a lot of water? While it sounds very economical, this sounds like a really watered down version of making a natural soap.

Lisa Bronner says:

Hi Patty – I apologize for my late response. The blend you mention is basically going to scour the clothes with the baking soda and borax, neither of which react with the soap itself. With a small amount of soap, you’re not going to get the beneficial grime-fighting properties of the soap. I would use one of the powders (I’d pick the baking soda) and the Castile soap.

Bianca says:

I have a top loading machine without compartments for the soap. I usually put my detergent straight into the water. Without a rinse cycle compartment to put the vinegar how should i do this?

Lisa Bronner says:

Hi Bianca – Either you can manually add the vinegar when the rinse cycle begins (which I would never remember to do unless I set a timer), or after the full cycle, add the vinegar, and set the machine to rinse again. The vinegar is only necessary if you have hard water.

NanCcan says:

I use Borax in both clothes washer and dishwasher to soften our very hard water. Has anyone here tried that?

tc says:

Been reading the thread above and the smell of vinegar has been mentioned a few times. I live in hard water area and would definitely need vinegar in the wash. However, my husband loves the smell of clean laundry that commercial products has. Me, not so much. Is there a way to make the laundry smell nice ? Can I add some kind of fragrance to the mixture ? Thanks.

Lisa Bronner says:

Hi tc – You can definitely throw in essential oils to the rinse vinegar. Try 20 drops (1/4 tsp.) and go from there to your liking. You wouldn’t want to put the extra essential oils in the wash water because the soap will just wash it right out. Another option I’ve seen is to take a clean rag or flannel square and put essential oils on that, and then throw that in the dryer. Kind of a homemade dryer sheet remedy.

It sounds like you’re informed already about the issue of fragrance in conventional detergents, but here’s something I wrote about it: Fragrance can be the most harmful ingredient in the mix. Here’s more info from the Environmental Working Group’s Healthy Cleaning Guide:

Mystery fragrance chemicals are a major allergy problem

Some respiratory allergies may be set off by fragrances, which are complex chemical mixtures commonly used to scent air fresheners and cleaners, personal care products and other consumer goods.

Fragrances are collectively considered among the top five allergens in the world (de Groot 1997; Jansson 2001). They can also trigger asthma attacks (Norback 1995; Millqvist 1996). Researchers at the Universities of Washington and West Georgia who surveyed everyday Americans’ experiences with fragranced cleaning supplies found that nearly one in five suffered headaches, breathing difficulties or other problems when exposed to air fresheners (Caress 2009). A study led by Alexandra Farrow of Brunel University in the United Kingdom linked air fresheners in the home to higher incidence of diarrhea and earaches in infants and headaches and depression in their mothers (Farrow 2003). A Swiss study published this year found that use of air freshening sprays 4-7 days a week was associated with reduced heart rate variability, a marker of autonomic cardiac dysfunction (Mehta 2012). Because manufacturers routinely refuse to list individual ingredients in fragrances, independent researchers have difficulty conducting targeted studies to identify which fragrance chemicals raise the greatest concern.

Vicki says:

Put your “fragrance” in your laundry when you dry it. Buy some dryer balls and put essential oil on them before you throw them in the dryer with your clothes (I use 3 in each dryer load) you can put the oil on 1, 2 or all three balls depending how strong you want the fragrance. The dryer balls also help cut down drying time. Aura Casia essential oils makes a blend called Petal Power that reminds you of what a commercial detergent would smell like.

Mary Rush says:

For dishes. Is lavender castile ok? The store didn’t have plain castile. And I am out of dish soap.

Lisa Bronner says:

Hi Mary – Yes, the lavender is great!

Lisa Bronner says:

Hi Abigail – The Castile soap works great for washing wool sweaters. I like to fill a sink with cold water and swirl in a capful or two of the Castile. Dunk in the sweater and wash. Rinse fully and dry flat.

DJ says:

Which scent of castile soap would you use for laundry? Only peppermint? Can you use in dishwasher? Thanks!

Lisa Bronner says:

Hi Teresa – Bar soaps are 5% water, while the liquid soaps are 61% water. The chemistry is a little different for both, but considering that a bar soap is 5 oz., and thus 4.75 oz. of non-water soap, you would need 12.18 ounces of liquid soap to equal the soap content of a 5 oz. bar.

Van says:

Great question, Teresa and thank you for the great answer, Lisa.

Lisa Bronner says:

Hi Amy – Silk sheets need a gentle, clean rinsing detergent, which is exactly what our Sal Suds Biodegradable Cleaner is, Ideally, washable silk should be hand washed, but that sounds pretty laborious. I’d use cold water and the gentle setting on your washer. Use just a couple Tablespoons of the Sal Suds and a shorter wash time. Drying is tricky because line drying is best but sunlight can fade silk pretty quickly. Drying sheets indoors is a bit much, but perhaps you could do it over a shower rod. If you’d rather use your dryer, try them on the Air Dry (no heat) option, or on the lowest heat option. Remove them immediately once done.

Sharon Hall says:

Hi there, great Article.
I have a quick Q – Does the c. in measurements such as 1/2 c. mean a cup or centiltres.
Sorry an Australian here so not aware what reference you’re using.

Lisa Bronner says:

Hi Sharon – I’m so glad you asked. I need to keep our international customers in mind and update my measurement references. It does mean “cup” which is roughly 240 milliliters.

Janesia says:

I have a GE top-loading washer machine and would like to try using Dr. Bronner’s Castile soap for the first time. Is it necessary to add vinegar? Does it make a huge difference to the way the clothes are being washed ?

Lisa Bronner says:

Hi Janesia – It all depends on how hard your water is and what you’re washing. If your water is not hard, you definitely don’t need vinegar. If you have hard water and you’re washing towels, you will probably notice a stiffness in the towels and a drop in their absorbency. It basically functions as a fabric softener. Feel free to experiment with it both ways. The vinegar smell dissipates entirely when the laundry is dry.

Van says:

Agree with Lisa about the vinegar smell dissipating after the fabric dries.

Deborah says:

I live In Germany, so have an HE front loader and hard water. Vinegar does´t sound so fun, so I have been wondering about trying baking soda instead of vinegar to soften the water….have you any experience with that?

Lisa Bronner says:

Hi Deborah – I do add baking soda to my laundry sometimes, as well. However, I add it for whitening and deodorizing purposes. It is an alkaline. Vinegar is an acid, which lifts the mineral deposits that hard water leaves behind. I don’t think baking soda would have the same effect.

Van says:

Just read an article over on the DIY Natural site and the author recommends baking soda over vinegar for fabric softening. What I don’t understand is that the author states to add it to the wash cycle. I’ve used vinegar in the past and will continue to do so as it’s less messy than baking soda.

Yvette says:

In a HE washer…the soap would be 2Tbsp+2tsp of castille soap?? And it should be placed into the detergent cup and not on the bedding correct?

Lisa Bronner says:

Hi Yvette – Generally we say that an HE machine would take half of what a regular would take, so for the soap that would be 1/4 c. of soap and vinegar. For the Sal Suds, that would be 2 Tbsp. of each. Put the soap or Sal Suds in the detergent spot and the vinegar in the fabric softener spot.

Sara says:

1/2 1/3 c. You mean a cup or you mean the cup of the soap bottle.Thank you ?

Lisa Bronner says:

Hi Sara – A measuring cup, which is about 119 ml for a 1/2 cup or 79 ml for 1/3 cup.

Emmaline says:

Would love to try this but I am worried about the vinegar reacting to the Castile soap and making the slimy substance when they are combined. We have a new he washer and I would hate for it to get mucked up.

Lisa Bronner says:

If your fabric softener compartment doesn’t release until after the soap is rinsed out, you would be all right. However, I don’t know how you would test that. Maybe your manual would say. You are right in thinking if the two combine in your laundry, it would be a mess. Dr. Bronner’s Sal Suds doesn’t have this issue, though. If you used the Sal Suds with the vinegar, you would be fine.

Caley says:

I have heard you can use an organic conditioner instead of vinegar in the rinse cycle. Has this worked? Will it perform the same?

vee says:

hi,im wondering in the measurements, does ‘c’ stand for cup or cap or laundry cap or dr bronners bottle cap?….

Christine H. says:

Most recipes use c or c. for an 8-ounce cup.
If the recipe calls for the bottle’s cap, it would be stated plainly such as “Dr. Bronner’s Castile Soap bottle cap.”

Jeanine Oomen says:

Hi, I’m from the Netherlands an d I don’t know what a HE Machine is? I have just a normal Bosch machine.

Christine says:

High-Efficiency Washers
HE washers use much less water and energy. On the other hand, they have longer washing time.
Standard laundry detergent is not recommended for HE washers since less water us used in each load.
Too much detergent woillclog up the machine because the amount of water it uses is not sufficient to rinse it out. That build up can cause the machine to malfunction and to eventually create an offensive odor.
Most HE manufacturers and their warranties suggest special HE detergent.

If one were to use regular laundry detergent, use less of it. A lot less — approximately one-fourth the amount you might normally use and dilute the detergent with water before pouring into the machine..

Andrea says:

HE Machines are front loading cloths washing machines. In Europe American Top-loading washers are almost unknown… You most likely have a HE washing machine. (I am originally from CH and know this.)

RD Wolff says:

“Most HE manufacturers and their warranties suggest special HE detergent.”

They are full of it, they will find a way to get out of the warrantee ANYWAY no matter what you do. I made the mistake of buying a new Whirlpool washer that turned out to be one of those HE washers, I had no idea what I was getting into with that junk! it puts only about 3″ of water in this huge tub no matter what you set the cycle to be, and after defeating the lid lock I was able to watch the thing during a cycle and it was a joke! some of the clothes never even got wet!
After that I started adding two 5 gallon pails of water to a full load once the wash started so it gets a good amount of water in the thing and select the extra rinse. I’ve only used regular powdered Tide laundry detergent but half the amount, and all is fine. There’s NO WAY I’m buying any expensive overpriced “special HE” detergent- it’s a RIPOFF and they have consumers fooled that they HAVE to use their special detergent!

Next washer I’m going to buy will be one of the Speed Queens, they still make washers that DONT restrict your water and have an agitator and will fill the tub for a proper wash

Lisa Bronner says:

Hi Jetta – My household doesn’t know the meaning of “small or medium loads”. 🙂 I use 1/2 c. in a large load, so for smaller loads, use less.

Deb says:

I recently learned the best way to eliminate static cling is to reduce your drying temperature to medium and dry them for longer. I have been using this method and have eliminated my static cling problem. I didn’t realize it would be so simple. It also allowed me to eliminate the extra cost of fabric softener or dryer sheets and there chemicals.

Sharon Scowcroft says:

Wool Yarn Balls work for the static cling, you can make them or purchase them online, just do a google search. I have used aluminum foil balls for static but I think the aluminum could be toxic so I stopped using that.

Cyrisse says:

How much can I dilute solution to make a dish detergent ? Love this product !

Sue says:

I too am wondering about the vinegar. Apple cider or white? Is this thread closed?

Noelani says:

Yes this is a question I have too. Will it work in cold water?

therese says:

What do you use to reduce static cling. I have used white vinegar in the rinse cycle but there still remains static cling after using the dryer. Thanks!

Debbie S says:

Jim, I use Heinz white vinegar in my fabric softener compartment in my HE washer. It reduces static, softens clothes, and gets rid of any residue. Heinz supposedly smells the best as far as vinegar goes. You can’t smell it on your clothes. Good Luck!

Jo H says:

Distilled white vinegar for the laundry. I’ve used it very successfully as a “fabric softener” in the laundry. Be aware though, I have also had horrible results with it. In our current water, the vinegar leaves a horrible stink when used in the rinse, but is still wonderful for initial disinfecting on towels and children’s bedding when used in the pre-wash cycle. If you find you have stink issues after using vinegar in the rinse, don’t be afraid to drop it.

About Lisa Bronner

My grandfather was Dr. Bronner, my family makes soap, and I share ways to use it plus tips on greener living.

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Print Now!

Castile Soap Cheat Sheet

Dilute! Dilute! OK! But how much? Print this guide!