The KIRI Patch vs. DEET Products


The use of DEET as a safe chemical in repellents is a controversial topic and somehow the answer “it depends” seems so appropriate. The topic is “controversial” because although DEET is deemed safe for use as long as guidelines are followed, there have been a number of cases where DEET has been identified or suspected as the culprit for serious side-effects and sometimes death. It should also be noted that several of the cases have shown that the side effects impact children in much larger numbers than adults.


So the question remains, to DEET or not to DEET? It depends. It depends on geography, intended time of use, who it will be used on, availability of alternatives, diseases at risk, your risk aversion... etc. If applied on a child, the parent should also consider the possible risk of ingestion (maybe when you are not looking) or whether you will remember to wash the DEET off your child as well as the child's clothes. It depends.


Conclusion: After reading all this, you might be wondering if DEET is worth the risk. On the other hand, studies suggest that DEET is still the most effective insect repellent available and depending on your situation, its use might be the best option. Dengue Fever and Malaria aren't pleasant alternatives. But it's up to you to weigh the facts and make your own decision.


Want to learn more... please feel free to read on.


The following are facts about DEET which the consumer should consider in making their choice to using DEET or applying it on their children.


The EPA currently rates DEET as Toxicity Category III, the second lowest of four categories -- or "slightly toxic" [source: EPA].

As with most chemical compounds, DEET doesn't come without warnings or side effects. The U.S. Environmental Protection Agency (EPA) reregistered DEET in 1998 to ensure it conformed to today's more stringent standards (rather than the 1950s standards). Because DEET is applied to the skin and not directly on plants or wildlife, its impact on the environment is minimal. The approval for use by the public and “slightly toxic” rating was given only when the EPA considered that public DEET use was “brief… and not long-term use”. Today, it remains controversial to what the EPA meant by the term “brief”.


Overuse and Incorrect Use of DEET is bad for you.

So, is DEET bad for you? The answer isn't totally clear. Overuse of DEET can have lethal consequences. Even so, data from 1961 to 2002 shows only eight DEET-related deaths. Three were from deliberate ingestion, two from dermal (skin) exposure and three were children receiving heavy and frequent applications of DEET [source: Agency for Toxic Substances & Disease Registry]. The EPA stresses that DEET is perfectly safe when used in accordance with the directions on the label. Incorrect application can lead to health issues such as skin irritation, disorientation, dizziness, seizures or in very few cases, death [source: ATSDR].


DEET is absorbed into the skin.

Researchers applied technical grade DEET, and DEET formulated in a 15% ethanol solution, to the forearm skin of male human volunteers for an 8-hour exposure period. DEET was absorbed within two hours after application and absorption continued at a constant rate over the 8-hour exposure period [source: National Pesticide Information Center]. The Medical Sciences Bulletin, published by Pharmaceutical Information Associates Ltd. reports, up to 56% of DEET applied topically penetrates intact human skin and 17% is absorbed into the bloodstream. DEET is also absorbed by the gut.


The CDC can't say whether DEET causes cancer.

You hear rumors that DEET causes cancer. This may partly be due to the fact that people confuse DEET with DDT, a known carcinogen. In truth, scientists have not established a direct link between DEET and cancer. The Centers for Disease Control and Prevention (CDC) classifies DEET as a group D carcinogen -- meaning it's not classifiable as to human carcinogenicity. In simple terms, that means that they can't say it causes cancer, but they can't say it doesn't, either. Interesting enough, DDT was also approved by the EPA for widespread agricultural use on our food until it was shown to cause birth defects and had devastating effects on the environment. Only then was DDT banned.


DEET identified side-effects documented.

The activist group Beyond Pesticides keeps its own list of documented DEET health and environmental effects:

  • Cancer: Not documented
  • Endocrine Disruption: Not documented
  • Reproductive Effects: Not documented
  • Neurotoxicity: Yes
  • Kidney/Liver Damage: Yes
  • Sensitizer/Irritant: Yes
  • Birth/Developmental Defects: Yes
  • Detected in Groundwater: Yes
  • Potential Leacher: Yes
  • Toxic to Birds: Not documented
  • Toxic to Fish/Aquatic Organisms: Not documented
  • Toxic to Bees: Not documented


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. Abou-Donia also found that combined exposure to DEET and permethrin, a mosquito spray ingredient, can lead to motor deficits and learning and memory dysfunction.


Some researchers have even tied DEET to the mysterious Gulf War Illness suffered by ­many veterans of the 1991 war.

Numerous soldiers reported symptoms­ like chronic fatigue, headaches, dizziness, loss of muscle control, memory issues, and muscle and joint pain. Studies in the mid-1990s showed that a combination of pesticides, including DEET, and an anti-nerve gas agent caused similar symptoms when tested on animals and insects [source: Waters].


If you are going to use DEET, use it correctly!

That said, you're probably wondering how you can use DEET safely. DEET is an important weapon in the fight against mosquito- and tick-borne illnesses, so it's definitely got its value -- you just have to make sure you use it according to the label's directions. DEET has been proven to enter the bloodstream through application to the skin, and while many people use DEET-based products without incident, others have suffered side-effects ranging from rashes and hives to uncontrollable twitching and muscle spasms to death. Children seem especially susceptible to DEET problems.


In 1998, U.S. EPA required companies to list precautions on their product labels and made it illegal for any product containing DEET to make any child safety claims. Products with DEET are required to carry instructions that they should not be used at all for children under 6 months. Additional required warnings state that for children 6 months to 2 years, only concentrations of less than 10% DEET should be used, and only once a day. For children from 2 -12 years old, only concentrations under 10% should be used, and repellents should not be applied more than 3 times a day.


It should be noted for adults, Canada has now banned products with DEET concentrations over 30%, citing health risks and evidence that increasing the percentage does not do much more to repel insects. Health Canada has also banned two in one products which combine sunscreen and DEET, saying they create the potential for people be exposed to too much DEET.


The following are some general guidelines about using products that contain DEET:


  • Buy a repellent that has a DEET concentration of 30% or less. A higher dose increases the chance of side effects. For most one or two hour outings, a 10% concentration in a product is sufficient.
  • Don't use any product that has DEET and sunscreen mixed together. Unlike DEET, sunscreen requires frequent reapplication. DEET doesn't wear off as quickly as sunscreen, so you could end up with unsafe amounts of DEET on your skin.
  • Apply DEET only to exposed skin and/or clothing. Don't put DEET on skin that will be covered by clothing -- this will cause your skin to absorb the DEET.
  • Don't use DEET on any open wounds or rashes.
  • Keep DEET out of your eyes, mouth and ears.
  • Don't spray it directly on your face.
  • Avoid inhaling it.
  • Don't apply DEET near food or use it in enclosed areas.
  • Apply DEET in a thin layer -- just enough to cover your exposed skin. Avoid heavy application or oversaturation.
  • Once you return indoors, make sure you wash off the DEET with soap and water. It's especially important to do this if you plan to reapply the DEET later or the next day


To Conclude

After reading all this, you might be wondering if DEET is worth the risk. On the other hand, studies suggest that DEET is still the most effective insect repellent available and depending on your situation, its use might be the best option. But it's up to you to weigh the facts and make your own decision.