Thermacell Portable Mosquito Repeller

By: Peter
Last updated:
Thermacell Mosquito Repellent Device

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If you attract mosquitoes like a magnet and you’re looking for a way to keep them at a distance, the Thermacell Portable Mosquito Repeller could be what you’re looking for. It’s a DEET-free and no spray repellent!

In this review, you will discover the advantages of using this product.

What is the Portable Mosquito Repellent Device?

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Thermacell MR300 Portable Mosquito Repeller

This is a small mosquito-repelling device measuring just 7.8″ x 2.9″ x 1.8″ (LxWxH) and weighing 0.4 pounds. This means it can be carried around and used anywhere you need it, for example, when you’re fishing, hunting, camping, in your garden, or even when you’re walking. You can be totally mobile and not have to spray yourself with unpleasant repellents.

The Thermacell devices create a 15 ft x 15 ft (depending on the wind) mosquito-free zone.

There are 3 different models of this portable device, although they are quite similar.

  • MR300 Portable Mosquito Repeller
  • MR450 Armored Portable Mosquito Repeller
  • MR150 Portable Mosquito Repeller

The models MR150 and MR300 are very much alike. The MR450 has some added features – rubber armor, a zone check (a light will give you a visual indication of when the protective zone is created), a belt clip, quieter ignition, and better ergonomics.

How does it work?

These portable devices work the same way as other Thermacell products, lanterns, or torches. Even the latest battery-operated Radius Repeller or E55 Mosquito Repeller uses a similar system.

You insert a repellent mat under the black gill. Then you insert the butane cartridge by screwing it into position. Slide the “on/off” switch to the “on” position. Wait a few seconds and then press the start button 2 or 3 times in quick succession. When finished using, slide the button to the off position and leave to cool.

A small butane cartridge powers the device. The cartridge heats a mat that’s saturated with the repellent. With the heat’s effect, the repellent is dispersed into the air, creating a zone of protection. You have to wait for about 15 minutes for the repellent zone to form.

If you use a Thermacell repellent in windy conditions, you are recommended to place it upwind. The repellent will then be carried towards you. The device will probably be less effective on a windy day, but then again, mosquitoes don’t usually fly much when it’s windy.

If you intend to use a Thermcell repeller at more than 4500 feet, you may have difficulties lighting it and keeping it running due to lower air density. The Radius and the Backpacker will work up to 7000 feet.

The butane cartridge will last for 12 hours, and each mat with the insecticide lasts for 4 hours. When you purchase the repeller, you have one cartridge and three mats, so you’re good for about 12 hours of protection.

You can buy refills at most major online retailers – Amazon, Walmart, Home Depot, Lowes… and many hardware stores or camping retailers.

You can see how it works in the video below.

The Repellent

Thermacell appliances use a repellent called allethrin. Allethrin is a synthetic version of pyrethrum. Pyrethrum is a botanical insecticide found naturally in chrysanthemum flowers. Allethrin was introduced in 1949.

Is Allethrin Safe For Adults And Children?

Thermacell has sold hundreds of thousands of repellent devices and millions of refill mats. Apparently, there haven’t been any health problems reported to the company.

There have been some studies conducted on the effects of Allethrin on humans. Even in a worst-case scenario, a Thermacell device was operating indoors, in a room with no windows or ventilation, and was running for 8 hours. The toxicologist running the study concluded that a Thermacell device does not pose an unreasonable risk to adults or children.

The product is registered with the EPA and is safe if used as per the instructions.

Field Tests

Several scientific field tests were carried out by different bodies using Thermacell devices, notably the Department of Defense and on 4 continents.

The results for mosquitoes, sandflies, and no-see-ums were quite conclusive. In an area of 7.5 feet on each side of the device, it was 95-98% effective. There was some protection up to 25 feet from the unit.

In a test against black flies, protection was optimal at 3.75 feet from the device. This test was carried out in windy conditions; in calm weather, the area would probably be greater.


  • Provides protection for an area 15 ft x 15 ft
  • Completely portable can be used anywhere. Dimensions 7.8″ x 2.9″ x 1.8″ and weighs 0.4lbs
  • Separately purchased holster means you can even use it when you’re walking or working in the garden.
  • Silent operation when repelling mosquitoes and other insects
  • Almost odorless
  • No open flame or contact with the skin
  • Refills of gas and repellent mean it can be used indefinitely
  • 12 hours of protection included
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A Few Safety Precautions

Although the device and the repellent are quite safe when used as , there are a few precautions you should be aware of.

The device might get hot while being used, keep it out of the reach of children. Only use outdoors, never in an enclosed space or tent. When using, you should cover any exposed food. The active ingredient, allethrin, is toxic for cats, bees, fish, and aquatic invertebrates. Be careful when disposing of your used mats. You should also avoid directly inhaling the vapor.


  • Portable can be used anywhere.
  • Easy to change repellent mats and butane cartridge. The mats last for 4 hours and the gas cartridges for up to 12 hours. There are also max life mats available, which last for 12 hours.
  • You can check the fuel level of the butane cartridge by holding it vertically and looking through the slot at the rear of the device.
  • Simple to get working out of the box
  • Cover a larger area by having more than one Thermacell Device


  • Can only use Thermacell mats and cartridges in the device
  • Running costs will mount up if you use it often
  • It will be less effective if there is some wind or you are mobile
  • It needs to heat up for a few minutes before it starts emitting the repellent
  • Only for outdoor use

Why Do You Need To Repel Mosquitoes?

Mosquitoes are very annoying. Their bites can cause irritation, swelling, and other allergic reactions. While all these things are unpleasant, the real reason you want to keep mosquitoes at a distance is that they can transmit dangerous diseases. It’s not only humans concerned with these pesky insects. They can also transmit diseases to dogs and horses.

There are about 200 types of mosquitoes in the US, of which 12 spread disease.

The diseases they can transmit to humans in the US are Chikungunya, Dengue, West Nile Virus, Zika Virus, Eastern Equine Encephalitis, St. Louis Encephalitis, LaCrosse Encephalitis, and Western Equine Encephalitis. You can find more information about these diseases on the CDC website.

Mosquito Control

The primary means of mosquito control is to eliminate any breeding grounds. This involves removing, covering, or emptying any item that can collect water. If you have water containers filled regularly, birdbaths, or saucers under plant pots, empty at least once a week. Larger volumes of water that can’t be emptied, covered, or drained, add a larvicide.

You can use an insecticide spray to kill adult mosquitoes. They like to rest in shady, moist areas; this could be in bushes, tall grass, under the eaves, or the decking. Mosquito traps are another alternative.


The vast majority of people who have purchased this device seem happy and say it works well, just as the field tests suggest. To have a small mosquito-free area, the Thermacell Outdoor and Camping Mosquito Repellent Device seems to work for most as promised and is recommended.

The repellent is harmless to humans and animals when it’s in the air but be sure to keep the mats away from young children. This device can give you a safe and effective way to repel mosquitoes and other biting insects. Easy to take on any outdoor trips you are planning, making this an exciting product.

Photo of author


Peter spends most of his time outside in his large garden. He has been fighting mosquitoes for a few years trying different traps and repellents without using agressive chemicals.