It is that buggy time of year again, and we always adore telling folks how effective aromatic oils can be as mosquito repellents on the skin and inside spaces – AND how to choose and blend the best oils. (See blends at the bottom.)
People are acting on to the fact that several essential oils are effective at repelling mosquitoes. Catnip essential oil has been tested as up to ten times better than DEET, the compound found in most over-the-counter “unnatural” formulas. This is good to know because DEET has been called a safety concern for children (which really means “everyone” doesn’t it?). Catnip and several other essential oils can prevent that risk.
An Iowa State University research group, which had previously found catnip essential oil to repel cockroaches, presented the report Meeting of the American Chemical Society.
Laboratory researchers contained twenty mosquitoes in a two-foot glass tube, half of which was treated with nepetalactone (found in high amounts in catnip oil). After 10 minutes, only an average of 20 percent or about four mosquitoes were near the part of the tube containing catnip. The same tests with DEET showed about forty percent (that’s eight or nine mosquitoes) remaining on the treated end.
The results from each tube were rated on a scale from -100 to +100, with 0 meaning half of the insects would be on the treated side, and exactly half would be on the untreated side. The tests of Catnip yielded values between +49 and +59, meaning thatthe majority of the insects traveled to the untreated side. The DEET tests produced results between +6 and +16, meaning that more mosquitoes remained in contact with DEET in the treated side of the tube.
To achieve similar results in repellency, researchers adjusted the dosages of nepetalactone and DEET, and found that one part nepetalactone produced an identical effect as ten parts DEET. Thus, nepetalactone is assumed to be ten times more effective at repelling mosquitoes. Commercial formulas usually use between 5-25% DEET, which means that your homemade natural repellent should require only .5-2.5% of catnip oil to be equallyeffective.
Given the increased effectiveness of Catnip essential oil, it takes less oil to produce the same benefit asone achieves using a higher quantity of the potentially harmful DEET. There are also two additional essential oils that provide repellency. Their scents are a matter of taste; the newest oil is Eucalyptus Citradora, which doesn’t exhibit Citronella’s classic scent of lemon-grass and may appeal to more people.
If you would like to make a pleasant and effective spray for the skin or clothing, you’ll need to add a little “tween”, a naturally-derived compound that helps oils and water to keep from separating. It is listed on at online shops that specialize in aromatherapy ingredients. Some people say use equal parts Tween and essential oil in your recipe, but we’ve noticed that we can use much less (perhaps 1/4) if we don’t mind shaking the bottle before we use it. Here’s some recipe ideas that work for us.
If you want to make a cream base (you could even add the oils to sunscreen, use any unscented cream for your base. You won’t need Tween if you’re mixing in a cream .
An example recipe might be this – in each ounce of water, add 30 drops catnip oil and eucalyptus citradora oil, plus 10 drops peppermint (limit the peppermint if anyone finds it too strong). Start with ten drops of polysorbate 20, and fill the rest of the bottle with water. Shake well and let sit overnight. Shake again, and if you feel you need more emulsifier, try adding another 5 to 10 drops.
When instead you diffuse these aromatics indoors in your home due to the expense of catnip essential oil you may select other well-known bug repellent oils instead, or perhaps only use 1/10th of your entire blend being catnip, the rest being other oils you enjoy! We recommend: lemon Eucalyptus, Citronella, Geranium, and a little Peppermint. All these oils have been noted effective, and we think trying out new formulas at home is simple and fun. As a best practice, make a note of your ingredients and proportions each time, along with the results.
Read more about the use of natural botanicals for skin care.