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Insect Spray Safety: Ingredients to Avoid and Why

does safe bug spray exist?

Nobody wants to be a bug’s dinner while they’re trying to enjoy a beautiful summer day. But the landscape is changing – society is becoming more informed about the potential hazards of what we put ON our bodies, and the hazards of those biting bugs seem to be increasing. An informed mom needs to know – are there safe, natural insect repellent options out there?

There are 3 considerations when choosing a safe insect repellent: risks of insects to humans, risks of the spray to humans, and risks of sprays to the environment.

Let’s break each one down today, and I have to tell you right away – as I did the research for this post, I was surprised by what I found (and equally surprised by what I’m about to write).

The Risk of Bug Bites & Insect-Borne Diseases

The risk of mosquitos used to be just annoying and itchy, but now we are seeing deaths in the U.S. from West Nile and Zika, and the stakes are clearly raised. Whether media is hyping the statistics or not…a nearly zero risk has definitely turned into something more.

What is definitely huge is Lyme disease (and Rocky Mountain Spotted Fever may be worse)! A few facts about Lyme Disease:

  • There have been 282,409 confirmed cases of Lyme in the United States from 2006-2016 – increasing over 80% during that time.
  • But – Lyme disease may be one of the most severely under reported diseases we have, because it is so hard to diagnose.
  • Lyme is called “The Great Imitator,” because its symptoms mimic many other diseases. It can affect any organ of the body, including the brain and nervous system, muscles and joints, and the heart.
  • Plus that classic “bullseye” rash you’ve been taught to look for? It only occurs in 30% of infections, and another 30% don’t have any rash at all! Most people diagnosed with Lyme disease after a long time don’t even remember being bitten.
  • The CDC estimates 300,000 people contract Lyme disease in the U.S. each year, 10 times what is reported – more than women diagnosed with breast cancer, to give you a benchmark. I would honestly guess, because of its varied symptoms, that many more cases exist and are mis-diagnosed as something else, like chronic fatigue syndrome, Multiple Sclerosis, arthritis, Alzheimer’s and more.
  • And just this week, the CDC warned that Lyme disease is now the fastest growing insect-borne infectious disease.
  • Sources: 1, 2, 3 (link removed), 4, 5, 6

I am truly more scared of Lyme than of cancer, and it’s the only thing I’d welcome prophylactic antibiotics for with open arms! Here’s what we did to treat naturally when our oldest had a tick embedded. Ew!

So let’s start here – the EWG says, “No single chemical completely repels important American ticks. Do not rely on any product to keep ticks away. Perform tick checks at the end of the day or when returning indoors.”

Seriously, everyone should have a tick removal tool of some kind, because getting the tick OUT of your skin before 24 hours passes reduces your risk of Lyme infection to almost zero. This article by the Survival Doctor is excellent and includes a superb photo of how darn small ticks can be!

Note: “Almost” zero isn’t zero, and reminds us not to be complacent about disease. The CDC concurs it is rare under 24 hours – but possible. There is a bit of controversy on that.

I’m going to read it as, “Get ticks out as fast as possible, save the tick and watch for flu symptoms no matter what, but breathe half a sigh of relief if you think you caught it within the first 24 hours.” Other diseases can have a faster transmission time. Read more: 1, 2, 3

Order a Tick Removal Tool Now (then keep reading):

Once you have the tool, be sure to read about how to remove a tick safely, because it’s not what your gut reaction probably would be!

A local friend shared on Facebook that she’s removed multiple ticks from her children this week, and I have other friends who have battled Lyme for years in multiple members of their family, including one who went on to develop an alpha-gal allergy, a life-threatening and often time-delayed reaction to all things mammal (she can’t even smell beef cooking without risking anaphylaxis, nor pet a cat).

That’s no dairy, pork, beef, or lamb on top of other neurological symptoms in her family…it’s just awful.

Lyme disease left untreated can be as life-altering as cancer is life threatening. I greatly appreciate Beth’s story of how her family naturally fought Lyme off (and builds their immunity against it for the future).

Bottom line:

The risk of insect-borne disease, in many areas of the U.S. and increasing at an alarming rate, is HUGE. This has changed my entire outlook on “safe” bug sprays and how to keep ticks and mosquitoes away.

Watch it!

If you prefer to listen/watch, I shared this info in a news spot recently:

YouTube video

If you can’t view the video above, click Non-Toxic Bug Sprays to view it directly on YouTube or join the conversation HERE on Facebook.

How Harmful are the Sprays to the Environment?

honeybee on broccoli plant

Although pesticides can be very harmful to the environment as a whole, that risk comes mainly from agricultural pesticides sprayed on acres and acres of crops, not personal insect repellents.

Mamavation is looking into this subject this year as well and also didn’t go the totally natural route.

There are a FEW important facts to understand when it comes to keeping biting bugs away while not compromising our ecosystem:

  • This is about killing beneficial insects like bees more than anything. We are in a honeybee crisis that we must not ignore, so the topic is still very important (but easy to fix).
  • Active ingredients that attack an insect’s nervous system are always toxic to bees. They include:
  • Imidacloprid (worst) in products like Bayer Advanced
  • Pyrethrin/Permethrin, for clothing only (a natural compound but still toxic to bees)
  • Phenothrin (synthetic pyrethrin) & Tetramethrin, in products like Cutter fogger

The bottom line, for once, is easy:

For the good of the Earth and your health as well, just don’t use backyard sprays and clothing sprays!

RELATED: How to Get Rid of Wasps and a Wasp Nest 

How Harmful are Bug Sprays to People?

how to remember which ingredients are safe to make ticks and mosquitoes go away

This one gets a little trickier, but the answer is FAR more encouraging than I thought.

When a naturally minded mama smells something as potent as bug spray with DEET, her mind automatically goes to the usual big culprits:

  • carcinogenic (cancer-causing)
  • endocrine disrupting (messes with hormones)
  • neurotoxic (interferes with memory, cognition, motor control)

It surprised me that there are plenty of well-tested, EPA-regulated insect repellent active ingredients that DON’T have any of these concerns (even DEET for the most part).

It also surprises me that this study showing that catnip essential oil is 10 times more effective than DEET at repelling mosquitoes hasn’t been replicated, shared widely, or experimented with in other ways with human arms and spray formulas!

Although I still lean toward our top-rated Wildthings with catnip for my own family (see all the non-toxic bug spray reviews here), we’l also look at 4 ingredients that are acceptable for serious insect bite protection.

RELATED: To Kill Ants Naturally, try this 3-minute DIY solution!

DEET (Acceptable With Reservations and Instructions)

I can’t even believe I’m saying this, but if the risk of tick-borne Lyme disease, in particular, was high, I might even let DEET go on my kids.

The EWG, known for being darn conservative when it comes to safety for human beings, calls it “imperfect but reasonable.”

However, please don’t read this as run out and buy a bug spray with the most DEET you can find!


Let’s learn about how it works, starting out with the bad side of the story: scientists don’t actually understand how DEET works!

That worries me a little, because then do we really understand how it might affect humans? But it’s been in use since the 1950s and studies show few to no ill effects on humans under normal usage.

Concerns with DEET

  • may irritate eyes
  • may induce neurological damage (but rate of adverse reactions very low — about one per 100 million persons)
  • may cause birth defects; may be tied to Gulf War illnesses.
  • NOT a known carcinogen or endocrine disruptor (yay!)
  • “The most serious concerns about DEET are its effects on the central nervous system. Dr. Mohammed Abou-Donia of Duke University studied lab animals’ performance of neuro-behavioural tasks requiring muscle co-ordination. He found that lab animals exposed to the equivalent of average human doses of DEET performed far worse than untreated animals.”
  • 100% concentration melts plastic, which means workout clothing, sunglasses and watches may be at risk.

How to Find the Right DEET Repellent

The most important fact to remember about DEET (and all chemical insect repellents) is that the concentration affects length of effectiveness, not HOW effective it is.

So for example, if you just need one hour of protection because you won’t be outside for long, 5-7% DEET would be plenty.

  • The American Academy of Pediatrics recommends no more than 30% concentration for kids, and the EPA agrees. HOWEVER, in Canada, they recommend no more than 10% DEET for kids under 12, and I’d prefer those more conservative standards. Unfortunately, that concentration is almost impossible to even find in the States.
  • Health Canada also recommends no more than 30% DEET for adults.
  • Anything over 50% isn’t necessary by all accounts except the bug spray manufacturer; it’s simply overkill (and you put your plastics at risk along with your health, see above).
  • Don’t use daily – this may cause rashes and other more serious adverse reactions.
  • The EWG mirrors Health Canada and recommends DEET 7-10 percent for short protection time and DEET 20-30 percent, especially when contained in time-release formulations, for longer periods.

Sources: 1, 2, 3, 4, 5

Again, the bottom line here is critical:

Concentration in relation to TIME is the key. More DEET in your bug spray only means it will work longer, not better. You pretty much never need a formula over 30% DEET.

DEET options to watch for:

what's more dangerous - bug bites or bug sprays?

Picaridin – the “Pick This” Choice

There were so many “P” words in the world of insect repellents, I had to do what I do best when teaching kids to cook – make up a memory tool.

Picaridin has a pretty good safety profile, so you can remember to “pick this” when you see the active ingredient.

Here are some facts on Picaridin:

  • Synthetic – repels insects, ticks, chiggers (created by Bayer)
  • Resembles natural piperine, from the black pepper family
  • Repels, doesn’t kill insects
  • Also named Icaridin (which breaks my memory tool!)
  • Supposed to be as effective as DEET without the odor and irritation – testing showed 8-14 hours for products containing 20% picaridin and 3.5-8 hours for products containing 10 percent.
  • Many products mix Picaridin with sunscreen, which is a BAD idea for 2 reasons: (1) This ingredient may reduce the absorption/effectiveness of the sunscreen, and (2) sunscreen should be applied every 2 hours and bug spray every 8, so you’d either under-apply the sunscreen or way over-apply the repellent. PLUS, if you know me at all, I’ll never recommend the conventional sunscreen ingredients in these products because the mineral options are so much better!

The only real red flag on this ingredient that I found was that it’s relatively new, developed in the 1980s and in about 20 products, which means we don’t have long-term safety testing available.

Usually, that’s a huge deterrent for me, and it still gives me pause here, but the research that has been done can’t find any issues yet – and it has been in use in Europe longer than in the U.S.

Bottom line:

Picaridin is a good choice for effectively keeping biting insects including flies, ticks, and mosquitoes away – look for 10-20% formulas without sunscreen.

Sources: 1, 2, 3, 4, 5, 6

Picaridin options to watch for:

IR3535 as Insect Repellent – “I Rock” with This Option

This active ingredient, like Picaridin, is comparable to DEET in efficacy but quite a bit newer as far as safety research goes.

Here are some facts:

  • Developed by Merck in mid-70s, used in Europe longer than US (registered in 1999).
  • Inspired by a naturally occurring amino acid, not environmentally persistent.
  • Repellent, not killer – basically tells insects via scent to “go away,” but it doesn’t stink like DEET. It masks your body’s carbon dioxide.
  • 10-30% concentration shows similar efficacy to DEET on ticks and mosquitoes, with some insects repelled less by IR3535.
  • No known human side effects, recommended by WHO for pregnant women during disease outbreaks.
  • Officially on ingredients lists as 3-[N-Butyl-acetyl]-amino propionic acid ethyl ester (Even I can’t come up with a memory tool for that one!!!)
  • Don’t use in the sunscreens because you’ll probably overuse the repellent.

Consumer Reports found in independent testing that IR3535 was NOT as effective as Picaridin or DEET and don’t recommend it as an active ingredient.

Testing showed the best formulas included 15-30% DEET, 20% Picaridin, or 30% Lemon Eucalyptus. Test from a USDA lab found the same thing, the IR3535 was far less effective than DEET.

It’s definitely worth checking out CR’s testing explanation and a really good video and pics of how the arm-in-cage testing works over there.

I don’t always agree with Consumer Reports, but their testing is certainly better than mine, and it reflects the longevity issues that we also have discovered with the plant-based solutions. I would like to see Wildthings go through their testing!

Sources: 1, 2 (Link no longer available), 3, 4

IR3535 options to watch for:

  • Bull Frog Mosquito Coast (but that’s a sunscreen too, so not a good idea!)
  • RR lotion – 10% concentration
  • Coleman SkinSmart – 20% concentration (CR’s top pick)
  • Bullseye bug repellent (at Home Depot (Link no longer available)) – 20% concentration

Oil of Lemon Eucalyptus – “Natural” Bug Bite Protection?

This EPA-registered active ingredient sounds like it’s plant-based, but it’s really the synthetically produced version of the insect-repelling ingredient found in eucalyptus leaves.

So again, based on a plant, but not exactly from a plant. This puts it squarely in the “hmmmm” category for me.

A few facts:

  • Just about the only natural product actually proven/approved to repel insects – and it’s not even truly natural!
  • There has not been much research done though, so it’s not recommended for kids under 3.

Sources: 1, 2, 3

Lemon Eucalyptus options to watch for:

To pull together the best tips, I loved this reminder:

We asked Marc L. Lame, Ph.D., clinical professor of environmental science at Indiana University in Bloomington, Indiana and Melissa Piliang, M.D., dermatologist at the Cleveland Clinic Foundation in Cleveland, Ohio for their Do’s and Don’ts to get the safest, most effective repellent protection.


  • Use products in lotion, pump or towelette form. They offer better application control than aerosol sprays. Better yet, spray (or pump) repellent into your hands first. Then apply it to the skin.
  • Base your repellent decisions on your activity. “If you’re going kayaking in a heavily wooded, mosquito ridden area, DEET is your best bet,” says Piliang, “but if you’re going into your backyard for a barbeque, alternative repellents are probably sufficient.”
  • Employ non-chemical ways to keep mosquitoes at bay. Stay indoors when mosquitoes are at their peak. If you must go outdoors, wear long sleeve shirts and pants. And remove standing water (including Fido’s water bowl), which is where female mosquitoes lay their eggs.
  • Wash clothing and repellent-coated skin at the end of the day.


  • Wear permethrin-treated clothing. “It results in unnecessary exposure to the pesticide and it’s more toxic than applying repellent directly to the skin,” says Lame.
  • Use more than 30 percent DEET. And research shows that products sporting more than 50 percent DEET don’t offer additional protection and could cause serious side effects.
  • Choose products that combine both sunscreen and repellent. If you reapply sunscreen every two hours (as advised), you risk overexposing yourself to repellent.
  • Use misters, foggers or belt devices. “They put you in a cloud of insecticide for hours,” says Lame, and they contain more toxic ingredients than repellents applied to the skin.

Source: NEA Member Benefits

There’s also a good chart of duration of protection for each ingredient from REI.

My ultimate bottom line

When even the EWG says that DEET is not terrible and Picaridin and IR3535 are also good (but they include the same warning as me about less longevity testing)  – is pretty much to do what this EWG article says if insect-borne illness risk is great!

They break down pros/cons of each ingredient and more or less recommend in order: DEET, Picaridin, IR3535 and oil of lemon eucalyptus. For everyday use when there’s no compelling risk of insect-borne disease, use Wildthings.

For the record, I’m still uncomfortable about the idea of putting any of these on my kids…but boy do I hate the idea of Lyme disease even more!

What do you think? Is the risk great enough that you’ll stray from the totally natural world? Should I?

More About Ingredients to Avoid in Insect Repellents

Avoid: Pyrethrin

With this ingredient and all of the ones below, we are talking about an insect killer, not repellent. At first glance pyrethrin sounds mighty natural, but I’ve come down on the side of “don’t bother.”

  • Pyrethrin is found naturally in chrysanthemum flowers (powder – literally crushed flowers).
  • Pyrethrin really doesn’t have serious human side effects.
  • This all sounds great except for the environmental impact!
  • Quite toxic to bees
  • Toxic to aquatic life
  • Pyrethrin is in wasp and lice killers often, some foggers
  • If you feel like you have to use one of these, don’t spray in the evening when bees are active and never use on flowering plants. Consider using pesticides that are safer for bees, such as neem oil. Insecticidal soap is also an excellent choice as it affects soft-bodies insects more readily than bees and is not harmful when dry.

Sources: 123

Avoid: Permethrin

Permethrin is in the same family as pyrethrin, but it’s synthetic as well. Permethrin is only to go on CLOTHING only and is usually sold in a spray to treat clothing or tents or in pre-treated clothing.

  • It stays on for 5-6 washings and degrades in sunlight in 42 days. It has a half life of about a day on a surface other than clothing.
  • It does not stain, does not accumulate in environment.
  • It is however, possibly carcinogenic. Some studies show it may cause dizziness and behavioral problems in children.

Sources say that permethrin on clothing is usually a higher exposure than people should have, especially if you treat your own. The spray in the air is problematic. To me, it just doesn’t sound worth it!

Sources: 12, 3

Avoid: Phenothrin & Tetramethrin

Although my friend at Mamavation says these compounds are acceptable, I’m going to land on the other side of the scale for the pesticides found in products like Cutter fogger.

  • Phenothrin is synthetic pyrethrin. Tetramethrin is also synthetic and is in the same chemical group, the pyrethroids (along with Permethrin).
  • Both are toxic to bees.
  • Phenothrin’s half life in air is less than 90 minutes (so it does degrade quickly), but in water over a month – It is less toxic than other options partly because it does break down so fast in the air. But then…isn’t your backyard only protected for a few hours? It doesn’t seem worth it to me!
  • Tetramethrin, on the other hand, is quite potently toxic for mammals.
  • Both might be an endocrine disruptor (noted in the EU) and carcinogen.

Sources: 1, 2, 3, 4

Avoid at All Costs: Imidacloprid

Imidacloprid is a systemic insecticide that acts as an insect neurotoxin and belongs to a class of chemicals called the neonicotinoids which act on the central nervous system of insects. It simply kills too many insects! This is in products like Bayer Advanced.

Unless otherwise credited, photos are owned by the author or used with a license from Canva or Deposit Photos.

11 thoughts on “Insect Spray Safety: Ingredients to Avoid and Why”

  1. I took a similar path researching and had similar conclusions. I ended up here trying to find out why deet in spray form is even a thing. The recommend use is that you spray it in your hand then rub it on children. It says it on the can in very tiny print buried in tons of other tiny print. You did great research but even you didn’t mention the most important safety step in using deet spray with children and it’s on all cans of spray deet as far as I can tell.

    For something that you don’t want in your eyes or lungs it seems ridiculous to turn it into a fine mist.

    I have never seen a parent apply spray repellent in the way that is recommended and I’ve been having a difficult time finding sorces that highlight the befinits of the deet lotions or wipes vs sprays.

    I have yet to find anywhere that asks the question if you are supposed to spray it on your hand and rub it on like lotion why is it spray in the first place

    The downsides of spray sunscreen vs lotion seem pretty well discussed. The results of uneven sunscreen are very easy to test and feel (ouch!)

    The first result for a “best bug repellent” in Google is a list of all sprays with absolutely no mention of lotions. Its a new York times Wirecutter article

    I’m sorry I’m frustrated rant over

    1. Carolyn @ Kitchen Stewardship

      Thanks for posting here Scott! You bring up some good points! I’ve never seen someone apply bug spray by spraying it in their hands first either. That really doesn’t make sense that it’s a spray in the first place!

  2. Thanks for all the information. My husband has alpha gal allergy from a tick bite. We definitely use insect repellent now if we are out fishing or anything like that. I don’t like it but seeing what he goes through, I don’t want the kids to have to go through that.

  3. I find this article fascinating and I appreciate all the research that went into it. I do want to point out that using a tick tool is not the safest method for tick removal. To twist a tick can cause it to be agitated, regurgitating toxins back into our bodies. Use fine tipped tweezers, getting close to your skin, grasp the head and slowly pull straight up.

  4. Hi Katie,
    I so appreciate all the time you spend researching these topics. I always recommend your sunscreen reviews to my friends! I know you are very careful in what you present. One question I have about this article/subject, though, is the point about your chance of Lyme being almost zero if the tick is on less than 24 hours. I have been told by many that this is simply not accurate. I see you linked the survival doctor article so I tried reading through that for sources and don’t see anything. Do you know any more about this, or were you just trusting the Survival doctor? I noticed someone also mentioned that this is false in the comments on that article. I don’t even know how to tell if this is true so I was wondering if you had any sources to back it up.

    Also, I would suggest looking into rose geranium essential oil as a tick repellent. I had heard amazing anecdotal evidence about this and haven’t had a tick since using it. Thanks, Julie

    1. Katie Kimball @ Kitchen Stewardship

      Hi Julie!

      I’m glad you asked this because you’re right, the evidence isn’t as conclusive as the Survival Doctor presented it.

      The CDC concurs it is rare under 24 hours – but possible. There is a bit of controversy on that. I’m going to read it as, “Get it out as fast as possible, save the tick and watch for flu symptoms no matter what, but breathe half a sigh of relief if you think you caught it within the first 24 hours.”

      I’m updating the post now to add some more reference links – thank you!

      1. You’re awesome! I just don’t like giving people that false security, ya know?

        And I just don’t always trust the CDC when it comes to information about Lyme, as I think there’s a lot of evidence that it’s way worse than they admit.

        Thanks again, Julie

    2. Hi Julie, The Wildthings repellant Katie recommended has rose geranium listed as the first ingredient. 🙂

  5. Hi Katie,

    I was on the Wildthings website ordering their bug spray (thanks to your recommendation) and noticed they also have a Wildthings Extreme version in a jojoba oil base. Have you tried this product at all and if so, would it be comparable to the deet/picaridin/IR3535 products for repelling ticks?


    1. Katie Kimball @ Kitchen Stewardship

      Yes! Exactly – the Extreme is more powerful than the water-based spray, and I believe it was that one that lasted 5 hours in the USDA testing. It’s just less convenient because it’s all oil, no spray. It smells great and lasts a long time though!
      🙂 Katie

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