Natural repellents — A better choice to keep the bugs away
by Karen McGeorge Sanders
This article was originally published in June 2005
Your breath attracts them. Unfortunately. “They” are mosquitoes. Like other insects, such as hornets, black flies, ticks, gnats and fleas, they’re part of the ecosystem. They’re an important food source for frogs, fish and birds, but annoying to humans and they can spread disease.
Insects bite us not to spread disease, but for food or protection. Female mosquitoes bite animals for the blood as a protein source to develop eggs. Hornets and yellow jackets are aggressive when feeding or defending their nests.
What else attracts insects? Mosquitoes are attracted to carbon dioxide, lactic acid, perspiration, dark clothing and fragrances. Bees and wasps can be attracted to bright clothing, scented products and sweet foods, such as watermelon and ice cream.
To keep insects at bay, people choose repellents and insecticides from a large variety of sprays and oils. A smart shopper will look at both the active ingredients (what repels the insect) and the base (what the active ingredient is mixed with), which is listed as inert or inactive ingredients.
The base serves to dilute the concentration of the active ingredients and makes the repellent easier to apply, while covering more surface area. The most common bases are water, alcohol and oils, but other inert ingredients may be beeswax, vitamins and citric acid. Generally, natural products should be applied more frequently than synthetic ones to be effective. As with any product, read and follow all label directions.
Over the counter
DEET (diethyl-3-methylbenzamide) is the most widely used insect repellent in the United States today. Approximately 38 percent of the U.S. population uses DEET-based repellents due to their long-lasting and effective protection.
Developed by the U.S. Army in 1946, DEET has a reasonably good record. But products with more than a 50 percent concentration should be avoided (10 percent for children, says the American Academy of Pediatrics). Adverse reactions to high concentrations include memory loss, headache, weakness, fatigue, muscle pain, tremors and shortness of breath. DEET also can melt plastic.
Pyrethroid formulas also are common, sold as indoor aerosols for flying insects and in many lawn and garden products. Pyrethroids are synthetic compounds that don’t just repel but kill insects. They’re similar in structure to natural pyrethrins, which are derived from the flowers of a certain chrysanthemum.
But synthetic pyrethroids are more persistent in the environment and some are carcinogens and suspected endocrine disruptors. Skin contact can cause blisters and itching. Inhaling pyrethroids can cause coughing, chest pain or breathing difficulties, including acute asthma attacks. High levels can cause dizziness, changes in awareness, convulsions and unconsciousness.
Both DEET and pyrethroids are considered safe by the Environmental Protection Agency (EPA). But the Northwest Coalition for Alternatives to Pesticides (NCAP) doesn’t recommend using DEET or pyrethroids at all. NCAP suggests choosing natural repellents made from plant extracts.
Natural repellents
PCC sells a variety of natural insect repellents, including All Terrain’s Herbal Armor and Burt’s Bees’ Herbal Insect Repellent. These products use natural plant extracts to deter insects, such as citronella for mosquitoes.
Most natural repellents contain active ingredients listed by the EPA as minimum- risk pesticide products. This list contains 31 active ingredients, including citronella, cedar oil, garlic, geranium oil, lemongrass oil and soybean oil. These products are exempted from much of the testing done on products containing DEET and other pesticides, due to their minimum-risk status.
There are natural repellents, however, that have undergone extensive testing, such as Quantum’s Buzz Away. “Our formula uses eucalyptus,” explains Bruce Schennum, Quantum’s research and education director. “Since it’s not listed by the EPA as minimum risk, we had to do testing. When volunteers using Buzz Away put their arms in cages of bloodthirsty mosquitoes, Buzz Away protected people for about two hours.”
Another option is to make your own repellent. This way, you can alter the essential oils and bases to accommodate any allergies and target the insects you want to keep away. (See sidebars) Just because a product is natural does not mean it’s completely safe. For example, pennyroyal is toxic when ingested and shouldn’t be used if pregnant. Also, some people may be allergic to the various active ingredients or bases in natural products.
It’s worth noting that in April, after years of promoting DEET as the best defense against mosquitoes, the Centers for Disease Control and Prevention (CDC) recommended the use of two other insect repellents, a manufactured chemical called picaridin and natural lemon eucalyptus. According to the CDC, the plant-based repellent oil of lemon eucalyptus provides protection “similar to low-concentration DEET products in two recent studies.”
Since not breathing is not an option, those wanting to enjoy a summer outdoors should consider natural insect repellents. It’s a natural choice to keep the bugs away.
Ingredients in natural repellents
Aloe vera: Moisturizes, heals
Beeswax: Encapsulates the active ingredient essential oils, producing a water/sweat
Cedar: Repels mosquitoes, fleas
Citric acid: A natural preservative
Citronella: Repels mosquitoes, ticks, gnats, flies and ants
Geranium: Repels mosquitoes
Jojoba oil: Relieves skin problems and moisturizes
Lavender: Repels fleas, lice, moths and has healing properties
Lemon Eucalyptus: Repels mosquitoes, ticks and no-see-ums
Lemongrass: Repels mosquitoes, ticks, gnats, flies and ants
Mint: Repels wasps
Pennyroyal: Repels fleas
Peppermint: Repels mosquitoes flies, bees and ants. Has antibacterial properties, time-release action
Sorbitol: Humectant and emulsifer, occurs in berries and fruit
Soybean oil: Moisturizer, acts as a barrier against insects
Tea tree oil: Repels ticks, lice, soothes, antiseptic
Vegetable glycerin: Used for the encapsulation process
Vitamins C and E: Antioxidants
For more information, visit the Washington Toxics Coalition Web site at www.watoxics.org. Click on Publications, then Home Safe Home Fact Sheets.
Homemade insect repellent
Active ingredients:
1⁄2 ounce citronella oil
1⁄4 ounce lavender oil
1⁄8 ounce pennyroyal oil
1⁄8 ounce tea tree oil
1⁄8 ounce jojoba oil
Base:
16 ounces almond oil (or 16 ounces alcohol or vodka for a spray)
Mix citronella, lavender, pennyroyal, tea tree, and jojoba oils and blend with 16 ounces almond oil base before rubbing on your skin. For a spray, mix with 16 ounces rubbing alcohol or vodka. Be sure not to apply undiluted active ingredients to your skin! Do a spot test for irritation before applying.
To avoid making the repellent too concentrated, remember to add approximately two ounces of base for every 1⁄8 ounce of additional essential oil.