(Step 5 of 9 in the Bed Bugs Killer Ultimate Guide - Updated March 7, 2020)
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Is bed bug spray effective? Yes, if you understand what it's designed to do and you follow the directions.
First, understand that bed bug sprays do not eliminate bed bug populations when used alone. They don't. They can't. So, don't rush out to Home Depot and bring home a can that says it kills bed bugs and expect that they'll be gone when the can is empty. They won't be gone. You will still have bed bugs.
The US Environmental Protection Agency has approved more than 300 products for killing bed bugs. But not every approved bed bug spray is available in the United States, and some are only approved for use by licensed pest control operators. Most bed bug sprays used today are pyrethroids, which are synthetic pyrethrins.
Even though they are safer for humans and pets than insecticides used in the past, they have limited effectiveness. They kill bed bugs on contact, but many have no residual effect. So they are of little use once they dry. When dry, non-residual sprays do not kill bed bugs in hiding or their eggs. Similarly, they will not kill new bed bugs who enter your home after spraying. So is any bed bug spray effective?
This page looks at how and where to use sprays approved for killing bed bugs. First, a few precautions:
Never apply sprays more often than recommended on the product package label, even if you continue to see bed bugs. Overapplication not only endangers your health and that of your family, but it contributes to making insects more resistant to the recommended levels of the insecticide.
The exterminator who arrives at your home to treat for insects carries a tank with a wand attachment for spraying. The tank releases a liquefied insecticide that has been diluted from full concentration. Exterminators mix the insecticide with water, using as little as less than a 1% concentration, to make it safe enough to use in homes.
They do this because the Environmental Protection Agency sets standards designed to protect all of us, especially children, the elderly, and people with compromised immune systems, from the potential dangers of breathing insecticides. If you decide to do your own treatment, please follow the same standards. Overuse is just dangerous – and it won't kill the bugs.
Types of Approved Bed Bugs Sprays
The EPA divides approved bed bug sprays into seven classes of chemicals. When used alone, none is completely effective. We'll look at six here, and the seventh, dessicants, when we discuss powders. The six classes of sprays are:
Today, professionals are overcoming resistance by combining products, using either multiple pyrethroids or multiple chemical classes to prevent new spray resistant bed bug populations.
The main point bears repeating: sprays work best as part of an integrated pest management process.
Common Active Ingredients in Sprays That Kill Bed Bugs
The active ingredients allowed in sprays for treating bed bugs include:
These products dry quickly and are most effective when sprayed directly onto the bed bugs. Few have residual effects once they dry. A study funded by the National Pest Management Association (NPMA) found that bed bugs actually avoid areas that are covered by dried insecticide residue. Overspraying warns bed bugs to stay away from the insecticide. The University of Kentucky researchers who conducted the study found that, unless they were hit directly by the spray, only about 50% of the bed bugs died.
The exception was when the sprayed area also contained bed bug feces. Apparently, this increased their comfort level, causing them to stay in the area with the insecticide residue and increasing the residual kill rate.
Where to Apply Bed Bug Sprays
To determine where you can apply a bed bug spray you're considering, read the label. Then, follow it. This is essential for your safety and your family's. For example, some sprays are approved for use on your mattress; many are not. Some can be sprayed on the surfaces of mattresses or couches; others can only be applied to seams, folds, and other areas where you won't lie or sit. Other sprays are best applied in cracks and crevices.
Make sure that any spray you're considering has an EPA registration number on the label. Then, read the directions to see where it is approved for use.
These are the main locations you will apply bed bug sprays throughout your home:
This video recaps the places to look for bed bugs in your home:
How to Use Bed Bug Sprays
Bed bug sprays come in three main forms: ready-to-use liquid, aerosol, and concentrated liquid. Location, what's being sprayed, and the size of the area you're covering play a large part in determining which form you'll use. Because each is effective in areas where the others are not, you may need to use each type to complete your treatment program.
Ready to Use Liquid Bed Bug Sprays
Ready-to-use liquid bed bug sprays are best used when you can see live bed bugs. This is because they dry quickly, have little to no residual effect, and kill effectively only when they make direct contact with the bug. Here's a demonstration:
Steri-Fab® the spray used in the video, is a bactericide contact killer. It's a pyrethroid that is activated by a synergist, isopropyl alcohol. Steri-Fab kills bed bugs and their eggs on contact. It is EPA-approved for use on mattress surfaces and other sensitive locations, such as couches, because it has no residual effect.
Here's a comparison of three top ready-to-use liquid bed bug sprays:
Liquid Spray | Main Ingredients | Kills Eggs |
|---|---|---|
Oil-based (may stain), pyrethrin activated by piperonyl butoxide synergist (disrupts insect's enzymes that protect them against insecticides, lets the insecticide do its job) | Yes, kills on contact but not a residual spray | |
Cedar oil–base | Yes, kills on contact and residually for 10-12 days | |
Phenothrin pyrethroid activated by isopropyl alcohol synergist; water-based | Yes, kills on contact but not a residual spray (professional product, available to consumers but not sold in stores) |
These sprays can all be used to treat mattresses for bed bugs and their eggs. Click on the links in the table to read more about each of these liquid spray contact killers.
After stripping your bedding during the cleaning stage, next steam-clean the mattress and box springs if you can. When this dries, spray the mattress surface with a ready-to-use liquid until it's damp. Allow the liquid spray to dry before proceeding.
This might seem like overkill, but you want to leave bed bugs no chance of survival. Neither steam-cleaning nor the liquid bed bug spray has any residual impact, so any bed bugs you miss while doing this will continue to bite and reproduce. This is why it's important to encase your mattress and box springs after you complete your treatment of these areas.
If you don't encase the mattress and box springs, you'll need to spray them again every 7 to 10 days until all evidence of any bed bugs is gone.
Aerosol Bed Bug Sprays
Aerosol bed bug sprays, unlike liquid contact killers, have residual killing power. Most kill for at least two weeks after application. Because they last longer, they are best used for spot treatments and as crack and crevice applications. Avoid spraying them directly on surfaces where people sit or lie. Spraying for bed bugs on seams, tufts, edges, and folds is the preferred way to apply aerosol to furniture such as beds and couches.
Bedlam is an example of a residual aerosol spray. It's a phenothrin pyrethroid whose powers are activated by the synergist MGK 264. Bedlam kills by attacking the bed bug's central nervous system. It has a 100% knockdown rate within 15 minutes and will continue killing bed bugs who come in contact with the dried residue for up to six weeks.
It's safe for treating mattress seams and tufts, headboards, couch edges and seams, and floors as well as cracks and crevices. It is water-based and will not stain fabrics.
Further, it's safe for spraying pet bedding. However, it should not be sprayed on pets or people. Always remove pets and children from a room before spraying and keep them out until the area has dried.
Bedlam Plus is an example of an aerosol that combines multiple chemical classes to combat bed bugs who have developed a resistance to pyrethroid killers.
Bedlam Plus takes all the killing powers of Bedlam and adds a neonicotinoid, imidacloprid. This is a synthetic form of nicotine that disrupts the bed bug's nervous system by causing its nerves to fire continuously until they fail. When combined with the synergized phenothrin in Bedlam, it's very effective at killing bed bugs and their eggs. It can be used in all the same places as Bedlam. It's specifically designed to kill the most pyrethroid-resistant bed bug populations.
As with Bedlam, use the provided crack and crevice straw to guide the spray. Hold the can about 8 to 10 inches away and spray.
The two Bedlam products are used commonly by exterminators but they are also available online for purchase by consumers.
Here's a brief comparison of some of the most common bed bug aerosol sprays used by professionals that are also available to consumers. Note that many are dual-action killers; they combine two chemical classes to overcome bed bugs who have developed pyrethrin resistance.
Aerosol Spray | Main Ingredients | Kills Eggs |
|---|---|---|
Phenothrin pyrethroid activated by MGK 264 synergist | Yes, kills on contact and lasts up to 6 weeks | |
Two chemical classes - phenothrin pyrethroid combined with imidacloprid, a neonicotinoid; activated by MGK 264 synergist | Yes, kills on contact and residually for about 2 weeks | |
Two chemical classes - beta-cyfluthrin pyrethroid combined with imidacloprid, a neonicotinoid | Yes, kills on contact and lasts up to 6 months (professional product, available to consumers except in NY) | |
Chlorfenapyr | Yes, kills on contact and lasts up to 30 days (professional product, available to consumers except in NY and CT) |
PT Phantom II is a non-repellant bed bug spray, meaning that the insects are likely to walk through it because they can't detect it. The aerosols kill residually, but they are still contact killers. Bed bugs die only after they come into direct contact with the insecticide.
Because Phantom is a pyrrole-base, it only turns into an insecticide once the bug has touched it. It works by disrupting the cell's ability to use food, leading to the insect's starvation and death. So while it lasts longer than many residual sprays, it can also take longer to kill.
PT Phantom II should be re-applied only once every four weeks.
Temprid Ready to Spray works by combining two chemicals that each attack the bed bug's nervous system. The beta-cyfluthrin kills bed bugs who are hit with the initial spraying while the imidacloprid takes out those who touch the residue days or even weeks later.
Typically, aerosol sprays for bed bugs are recommended for cracks and crevices; spot treatments of non-surface areas of beds, chairs, and couches; box springs, headboards, and baseboards; moldings, beneath floor coverings and carpets; closets, shelves, curtains, empty luggage, and picture frames. Always read the product for specific recommendations and restrictions.
Using Concentrated Sprays for Killing Bed Bugs
Concentrated insecticides must be mixed and diluted with water before applying them. It's essential that you follow the directions on the spray package to get the right mix of chemical and water. More is not better. A higher concentration of pesticide is not better. It will not kill more bed bugs, and it might make them more resistant to future treatments. You can also jeopardize your health and that of your family.
Typically, you'll need a one-gallon sprayer. The directions will tell you the right water-to-insecticide ratio.
The directions will also tell you how much to spray and where.
Typically, you'll spray box springs, the non-surface areas of mattresses, the interior of bed frames, and headboards. Also apply it into the cracks and crevice of baseboards, corners, door frames, and window sills. Be sure to spray the legs and any parts of furniture that touch the floor as well as along the edges of any carpet.
Liquid Concentrated Spray | Main Ingredients | Kills Eggs |
|---|---|---|
Two chemical classes - beta-cyfluthrin, a pyrethroid, combined with imidacloprid, a neonicotinoid | Yes, kills on contact and lasts up to 6 months (professional product, available to consumers except in NY and CT) | |
Two chemical classes - metofluthrin, a pyrethroid, combined with clothianidin, a neonicotinoid | Yes, kills within 5 minutes after contact; lasts up to 1 month; can be sprayed on mattress surfaces and lasts 6 months; used by professionals but now available to the public; built-in sprayer, so no pump sprayer required | |
Yes, death comes within 24 hours after contact; lasts up to 3 months; high risk of resistance when used alone (professional product, available to consumers except in NY and CT) |
So, is any bed bug spray effective? Yes, if you use them as they were intended. Realize that sprays are most effective when they are one part of the integrated pest management program we have been laying out for you in this guide. Follow the program, making sure to isolate your bed, clean up clutter, wash and bag items as needed, vacuum, and steam clean. Then apply:
Take your time and be thorough. Expect to make multiple applications of spray treatments over the next several weeks until you have gone at least 30 days without bites or bed bug sightings.
Next: Adding More Residual Killing Power with Dusts
Remember that most insecticides kill by contact with bed bugs. Sprays' power dissipates quickly because most have no or little residual killing power. Adding a good dust or powder helps provide the one–two knockout power you're looking for, increasing the effectiveness of each method.
Did You Miss the Previous Steps in the Guide?
In case you missed it, click to read previous steps:
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Bed Bug Kits Make Treatment Easier
