We are looking at using diatomaceous earth against bed bugs.

However, we're having trouble finding any reliable information on how to use it properly.

Our questions are:

  • how should it be applied?
  • is it effective against bed bugs? How long does it take to kill them?
  • where should it be put? Everywhere, or only in specific locations?
  • how much should be applied?
  • how often does it have to be reapplied, and does it have to be vacuumed up?
  • after it's been applied, will a fan or wind disturb it and blow it into the air?
  • is it safe to apply it on the outside of a bed (i.e. the sides of the mattress or on the sheets) and leave it there while sleeping?
  • is it effective when wet? when the air is humid?
  • Not so sure this is a home improvement question. Might want to ask this over at a exterminator forum--or possibly gardening.
    – DA01
    Mar 19 '12 at 2:37
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    I've read through the FAQ again. It seems to be completely on-topic as far as I can tell. Mar 19 '12 at 4:16
  • 1
    BED BUGS ARE A REAL THING!? Aug 7 '13 at 21:20
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    @BlueRaja-DannyPflughoeft is everything okay with you? Aug 8 '13 at 11:02

We have used DE effectively to kill bedbugs, so I'll take a shot

how should it be applied?

We applied it around the borders of all the floors, sprayed it into the walls everywhere we could (mainly into electrical boxes - remove the covers first), and into the underside of plush furniture. In the basement we put it all over the ceiling and walls as well as squirting it into every gap we could find.

is it effective against bed bugs? How long does it take to kill them?

Yes. They will avoid it if possible, so its tough to say how long it takes to kill them, but when we applied it to a heavily infested house and the improvement was immediate.

where should it be put? Everywhere, or only in specific locations?

Anywhere bedbugs can get.

how much should be applied?

A dusting around the perimeter of each room, a generous squirt of dust into openings and several squirts into plush furniture is what we did.

how often does it have to be reapplied, and does it have to be vacuumed up?

We only applied it once and that did the trick. If you vacuum it up it can't help, so no don't vacuum it up.

after it's been applied, will a fan or wind disturb it and blow it into the air?

Depends on the orientation and strength of the fan. A ceiling fan? No. A box fan pointing at a line of DE? Probably.

is it safe to apply it on a bed?

You should seal your mattresses up with bedbug preventing covers, and squirt the DE inside that. DE is harmless to you, but you want to trap the bugs in the mattress. Leave the mattresses sealed for at least 2 weeks or longer to ensure the bedbugs get exposed. They can hide and live for a long time in a mattress but a solid month should deal with the birth cycle.

is it effective when wet? when the air is humid?

No and not very.

  • 1
    Thank you for the response! Just for a bit more clarification -- what was your method of application? I'm not sure what's meant by "squirt", I though it was a powder? And for the bed question: I'd heard it's good to put it directly on a bed, in case there any bedbugs crawling on the bed. So assuming the mattresses are already covered, is it worthwhile to put DE on the bed? Mar 19 '12 at 12:55
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    I used both the mini duster and the 12 oz bottle found on this page: dirtworks.net/Diatomaceous-Earth.html. And you put the DE on the bed, THEN you cover it to seal the bugs in with the DE. If cover is already on mattress, open it up and put the DE on the inside. Won't help if the bugs can't get to the DE after all. Mar 19 '12 at 13:22
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    "DE is harmless to you" I thought that too, but in reading a bit more about it on wikipedia, it appears some forms of it contain silica, which can cause respiratory issues.
    – DA01
    Mar 19 '12 at 14:17
  • @TheEvilGreebo I'm asking about dealing with the bugs that are outside the mattress cover. I'm not worried about the ones inside, since they're trapped. I've updated the question. Mar 19 '12 at 15:01
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    DA01 - DE is harmless if you don't inhale it. ;) Mar 19 '12 at 17:31

I've done a lot of research and found answers to some of these questions:

  • how much should be applied? According to this page, not much at all:

More is not better in the case of DE: bed bugs won’t walk through a thicker coating and so it won’t have a chance to kill them.


Do not use large quantities that are likely to be kicked up and inhaled, and do not place in windowsills where a breeze might blow the dust around.


What you want to do with DE is apply a light film. What I mean by that is a VERY LIGHT film. If you are applying it in a way that you are kicking up visible dust, you are putting WAY too much down.

  • is it safe? There is more than one kind of diatomaceous earth, make sure that you're using food grade product -- this is the only kind that's acceptable to use inside a home. However, even food grade DE must be applied with caution:

DE is an inhalation hazard per the CDC. It can cause silicosis. It can be quite safe when used properly but isn’t as safe as some hucksters make it out to be.


You do not want DE in your lungs, not even freshwater DE. [..] although fresh water / food grade DE is safe if used properly, you should probably use a good respirator mask when applying any dust (such as the one recommended below), and disposable waterproof gloves when applying this or any other substance. No dust is safe if inhaled.

Also, see here:

DE is a significant inhalation hazard. While it can be applied safely (a very fine dusting barely visible to the eye only in areas where it will not get kicked up into the air), if improperly applied as we have heard about people doing, it can do significant damage to your lungs. Often, you will not see the results of that damage until years after exposure, so unlike some chemical pesticides that cause immediate reactions to let you know you've been overexposed, DE doesn't have a way to alert you that you've applied it improperly.

The general recommendation seems to be to be very careful to protect yourself from breathing in the dust using a breath mask or respirator mask.

  • is it effective? How long does it take to kill bedbugs? Apparently, this can vary by brand of DE and there are other dusts out there that are also effective.

It may take more than a week to kill them, although whether this is because it takes that long after initial contact, or the bedbugs do not immediately come in to contact with it, may be unclear:

MotherEarth D (diatomaceous earth) was slower acting than Tempo or Drione, but caused substantial (>90 percent) mortality of susceptible and resistant bed bugs within four days and all bed bugs were dead after 10 days


I was in the pest control business for 35 years and yes DE can be an effective control. You don't have to buy it as a pesticide. You can buy it cheap as a food grade. I've added a link but have never used this supplier? One supplier is Earthworks Health but you can find several by searching online

Okay, after reading these posts I would agree with most of the information. Here's something that was missed. Bedbugs can live in a mattress for more than a year without a blood meal. If they detect control they’ll often go dormant until the chemical or control agent has gone. You cannot let down your guard for at least 18 months. DE isn't toxic but the dust can damage your lungs. At minimum buy a good dust mask from the hardware store and minimize your exposure to the dust when applying it. When you have completed a room close the door and let it settle for a few hours. Then clean dust from surfaces such as table tops and counters where dust isn't very pleasing to the eye. I don't know how crazy homeowners can get with this stuff?

Be sure to keep a lightly dust covered area under all baseboards and under all furnishings, particularly around legs. Dust all of the voids in furniture and inside the box springs. Dust the bed railings that support your box spring. Try not to have bedding touch the floor and treat around all of the bed legs.

You can try to make your bed an island, but remember these things like dropping onto things! They can detect the CO2 you’re emitting and can walk up a wall and across the ceiling and drop onto your bed. If they don't stay on the bed then they will drop to the floor. Anything cloth you can put into the dryer on high for 30 to 45 minuets. Be sure to include stuffed animals and all pillows. Heat will kill the bedbugs and any eggs.

The biggest problem you will face is getting an effective tool to apply the dust! Shop the internet or go to a garden centre and buy a proper duster. A cheap turkey baster from the dollar store will work some what. You may need to reduce the size of the tip for a good light dusting. But for the voids in furniture a bigger duster is better. Be sure to inject the dust all of the way around large items.

How long is it effective? That would depend on humidity where you’re living. Once it has gotten damp, it's done.

Remember these things look at walls and ceilings like we look at the floor. They move around on most surfaces. The really like woody materials, paper and cloth. There not big fans of slippery surfaces. One poster mentioned light switch boxes and electrical boxes, that’s very good. Now include all of the things hanging on the walls and any lifted wall paper. One bag of DE will save you a lot of grief and money, but you still need a significant amount of effort. Good luck!

  • Hi, welcome to the site. I added a general "shopping" link for DE to make this post less vendor-specific, but otherwise this is a great answer.
    – Niall C.
    Sep 23 '13 at 17:02
  • I think this answer would be improved by supporting the claims that are made, especially: 1) that bedbugs "go dormant if they detect control", and 2) the effect of humidity on DE. Sep 24 '13 at 17:14

I actually used a tint bottle, like they use in salons to color hair. I did cut the tip so the hole was bigger. Home Depot sells DE as a pesticide. Made by Safer. You must take apart your bed to treat it. If your framing is hollow make sure you squirt some in there. Take apart all furniture and cushions and get it inside. Clothing drawers and towels all should be washed and dried above 120 °F. Good luck! I did all that. And used a steamer and professional pesticide and I'm almost 7 days in and I still have them. Hope the DE works.

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