As summer approaches, so does the annual insect season. Consumers want to protect themselves and their outdoor spaces from insects and pests, but don’t want to use harsh chemicals or have a negative impact on the ecosystem. What are the latest ways to enjoy your summer bite-free?

How do Insect Repellents Affect the Environment?

Mosquitos are the deadliest animal on earth, causing more than 700 million annual deaths. Other summer pests like wasps, hornets, and ants are not as deadly as disease vectors, but do pose health risks to individuals and can make outdoor living less pleasant. However, many insecticides and repellents also carry a broad range of negative impacts.

  • Insects are essential for healthy ecosystems. Insects are the foundation of every healthy ecosystem on the planet. They pollinate plants, cycle nutrients, disperse seeds, and are a food source that is essential to every healthy food chain. Around the world, insect populations are in sharp decline, with potentially catastrophic effects for all other life forms. 
  • Knock-on effects of broad-spectrum insecticides and repellents. Unfortunately, as we now know, widespread use of various insecticides has the effect of killing beneficial species as well as the targeted pests. Historically, insecticides have been shown to move up through the food chain through natural predation, causing unwanted harm to higher organisms. 
  • Potential effects on human health and skincare. Even the safest, most natural insect repellents, like some essential oils, have been known to cause irritation and skin problems in humans. Research has demonstrated that mosquito coils and some compounds in topical insect repellents can accumulate in the body, potentially posing some health risks to consumers.  

Consumers want safe, sustainable insect repellents that can protect themselves, their families, and their outdoor environments from pests, without harming beneficial insects or damaging the environment. Despite this clear message, there can still be conflicting messaging between the results of scientific research, the recommendations of health authorities, and the claims of product manufacturers. 

Eco-Friendly Pesticides and Insect Repellents

For all these reasons, the best way to repel unwanted insects is to use topical products that protect a specific individual for a specific time period. When the products are safe and non-irritating to people, they can be used individually without widespread harm for the environment. 

Time honored insect repellents

  • Essential oils. Essential oils have been used as topical insect repellents for centuries, and are proven effective. The most effective oils for repelling insects are (source):
    • Lemon gum (Corymbia citriodora)
    • Lemongrass (Cymbopogon)
    • Basil (Ocimum)
    • Eucalyptus (Eucalyptus)
    • Specifically, the plant terpenes that appear to be the most effective at repelling insects are α-pinene, limonene, citronellol, citronellal, camphor and thymol. However, the effectiveness of topical essential oils degrades quickly. The most effective topical use of essential oils as an insect repellent is a formulation at 10% concentration, which repels 94.4% of insects at first application, and continues to provide up to 55.5% protection at two hours. 
  • Neem. Neem oil is an incredibly effective insect repellent. A solution of 2% neem oil and 98% coconut oil (source) used topically provides excellent protection against a wide range of mosquito species. Neem oil can also be added to kerosene lanterns at a 1% mixture and burned (source), to protect a space or a group of people from mosquito bites. 
  • Citronella. Citronella is also a highly effective mosquito repellent, repelling over 80% of mosquitos. 
  • Remember that, for best protection, topical insect repellents should be applied like sunscreen: cover all exposed skin areas, and re-apply after 2-4 hours, or after sweating, swimming, or other activities that may have washed off the repellent. Also like sunscreen, remember that many insect repellents have ingredients that may be unhealthy for aquatic ecosystems, and should be used with care when swimming or bathing in natural waterways.  Check our blog about innovations in sunscreen> here

Chemical insect repellents

  • DEET/diethyltoluamide. DEET is one of the most widespread ingredients in commercial insect repellents today. It repels mosquitoes, ticks, flesh, chiggers, leeches, and other biting insects. Although there is indication that DEET can metabolize and be detected in the body, and there have been instances of adverse reactions, most government regulators have found that these adverse reactions are related to the specific product formulation. DEET repellents have been sold in concentrations as high as nearly 100%. For health reasons, concentrations of DEET higher than 30% should not be used. DEET is also potentially toxic to some marine species, so avoid using it in or near wild waterways. 
  • Picaridin. Picaridin repels mosquitos, gnats, flies, fleas, and is most effective against ticks. Unlike DEET, it does not affect plastics or sealants, and has less potential for irritation and side effects. Picaridin is most effective at a 20% solution, but is also potentially harmful to marine wildlife and should not be used in or near wild waterways. 

Next-gen solutions

  • Biotech insect repellent. Biomolecules have been used in recent years in the flavor industry, engineering compounds that enhance the flavors of vanilla, valencene, and other sweeteners and enhancers. However, nootkatone, an engineered metabolite derived from grapefrute, has been found to be a highly effective insecticide and repellent, approved by the US EPA in 2020. Using an enzyme fermentation process, nootkatone is fast and cost effective to create, and repels ticks and mosquitoes. It also may repel bed bugs, lice, and other insect pests. Because it’s a volatile oil, it does not persist in the environment, and it’s safe and non-toxic for humans.
  • Insect repelling clothing. Researchers are experimenting with treating cotton fabrics with microencapsulated citronella oil, to develop insect repellent clothing. While this technology is still in its infancy, cotton fabrics have been developed that can repel mosquitos for up to 3 weeks. 

With all these options for safe, eco-friendly insect repellents, it’s easier than ever to protect your skin from pests without harming the environment. Grapefrute wishes everyone a safe, sustainable, enjoyable summer.