Natural Mosquito Repellents Aren't Automatically Safe
Sunday July 9, 2006
Here's an e-mail I received with important information regarding natural mosquito repellents. My Natural Mosquito Repellent feature includes a caution about the safety of natural products, but this letter does a great job of explaining the hazards:Dear Dr. Helmenstine,
In your recent article on natural mosquito repellents, you listed several "natural products" including "citronella oil, rosemary oil, lemongrass oil, cedar oil, peppermint oil, clove oil, geranium oil, and possibly oils from verbena, pennyroyal, lavender, pine, cajeput, cinnamon, basil, thyme, allspice, soybean, and garlic" as alternatives to registered repellents like DEET.
The suggestion that your readers (which includes many with no science background) should apply these chemicals to repel mosquitoes may lead to serious problems. Without explicit instructions, indiscriminate use of home remedies is potentially more harmful than using EPA registered repellents. At least we know that scientific investigation of potential health risks was done before EPA allowed repellents to be labeled as such.
As a person with a doctorate of philosophy in biomedical sciences, you must certainly be aware that fat soluble chemicals are readily absorbed through unbroken skin. While the amounts vary with the particular compound, indiscriminate application of these oils as "natural" alternatives to EPA registered insect repellents may be more harmful than the commercial products. Under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), mosquito repellents have gone through rigorous testing before being offered for sale as registered pesticides. The chemicals you listed are exempt (at this time) based on low acute toxicity, but there are other considerations. For example, accidental ingestion of any oil followed by vomiting can cause pneumonitis which is life threatening and difficult to treat. Exempt repellents are not required to be packaged in child-resistant containers, increasing the risk of accidental ingestion. Many household products are not coverd by the Poison Prevention Packaging Act. The American Association of Poison Control Centers’ "Toxic Exposure Surveillance System" and the National Electronic Injury Surveillance System data show that every year thousands of children are treated for ingesting household chemicals. Possessing and using home remedies which lack child-resistant packaging may be a much greater risk than using DEET or some other registered repellent.
Another type of risk is allergens in naturally occurring compounds. For example, it is thought that some pyrethrum derivatives are thought to contain allergens that may trigger asthma attacks.
The following two paragraphs appeared in Environmental Health Perspectives (EHP), the peer-reviewed journal of the United States' National Institute of Environmental Health Sciences. (http://www.ehponline.org/docs/1995/103-6/focus.html)
"Pyrethrins are the collective name for a group of six pesticidal compounds derived from pyrethrum flowers in the genus Chrysanthemum. Pyrethrum flowers and refined pyrethrin extracts with varying amounts of floral impurities, some of which are allergens, have been used in pest control for several centuries. Though pyrethrum extracts are relatively low in terms of acute toxicity, there is concern that pyrethrins and their synthetic counterparts, pyrethroids, can trigger allergic reactions, particularly among the nation's estimated 15 million persons with asthma...."
"Several derivatives of natural pyrethrin molecules, known as synthetic pyrethroids, are also widely used household pesticides and are suspected to be allergens. Some of these include tetramethrin, resmethrin, and allethrin, cumulatively found in over 30 million households. Thus, pyrethrin and pyrethroid products may need to be labeled with bronchospasm warnings for asthmatics."
(EHP is an important vehicle for the dissemination of environmental health information and research findings. EHP's mission is to serve as a forum for the discussion of the interrelationships between the environment and human health by publishing in a balanced and objective manner the best peer-reviewed research and most current and credible news of the field.)
Sincerely,
Robert Stone
Albuquerque, NM
Natural Mosquito Repellents | DEET Chemistry
Comments
Here comes big brother again
Yep – Big Brother.
He must work for the FDA, which is my way of saying “bug off.”
I did not get the impression that I was to “wear” any of the natural ingredients. I will place them around my small garden to help reduce the mosquito bites that I get. Anybody looking for “natural” solutions are not interested in applying just anything to their skin.
Another example of ‘natural’ ingredients with negative side effects, lavendar and tea tree oil applied to skin(just lotion!) or hair(just shanpoo!) causes breast development in young boys. Think about it. Natural may not always be synonemous with ‘good’ if it does things like that.
I foundthis very helpful actually. My grandmotehr who has COPD has a terrible mosquito problem and as I was looking for to avoid synthetic chemicals that might aggravate her condition, its very useful to know that natural solutions could do the same.
I was nourishing the belief that natural repellents are safe and effective and they will not do any harm to our health and the environment. But, this blog changed my perception completely. From now onwards, I will only try natural repellents after analyzing them very carefully.
I was told that vanilla and water and orange oil mix togeather was a good mosquito repellent.. Have you heard anything about this? We have grandchildren that come out here in the summer and the mosquito’s really do a job on them. They don’t like the Deet spray on them, and they are in and out,long enough in to have to be sprayed again before going out… Too much deet…. I don’t know if you answer e-mails or not,if you have an answer sure would like to hear from you… Thanks
Hi Diana & Kirby – cautions against natural products do not necessarily infer Big Brother’s involvement. Those who study homeopathic medicines, and even those lay men and women who have done trial and error know the dangers and sensitivities that can develop when you don’t know what you are doing.
My Mom, who is undergoing chemotherapy, can’t even drink something as natural and “benign” as Green Tea, because of the interference with the chemo drugs. Of course, we’d love for her not to have cancer at all, but if she has to go thru that intrusion of dangerous chemotherapy drugs, I’d rather not defeat their purpose by arbitrarily introducing something, even a natural product, and placing her health further in danger.
After reading Mr. Stone’s letter I cannot walk away without commenting. The gentleman has tried to make an argument against natural remedies by attempting to sound “scientific”, as well as just flat out trying to scare people(i.e. “…potentially be more harmful..”). That’s like saying don’t drink water because you could drown, or don’t breath the air because you could get lung cancer. He starts the thrust of his argument by saying something that sounds like it could be important and it is, “chemicals can be absorbed through your skin”, yes they can. Several of the substances listed at the beginning can be found in stuff you eat, but he also mentioned that “The chemicals you listed are exempt (at this time) based on low acute toxicity”. That means that yes they have been tested and yes they are safe to use. So he sees that his argument has a big hole in it so lets throw another scare bomb out there, “what if the kids get a hold of it”. I have yet to see a child resistant insect repellent container, and if you do please let me know. Responsible parents know how to keep “chemicals” away from their kids.
Finally he cuts and pastes an article that he found. You have to ask the question “Are any of the compounds listed at the beginning, part of the group that the article is reporting on?” The article is talking about compounds that are used as a pesticide, not as a repellent. There is a difference. You would think there was a link between these pesticides and natural remedies because the compounds mentioned are derived from a plant in the “genus Chrysanthemum”, but not all plants are the same, so it is wrong to make a broad assumption, like “natural remedies are bad”, based upon an article that is only talking about one plant and “synthetic” (also known as not naturally occurring” derivatives based upon compounds from that plant.
It is true that people can have allergic responses to natural products. However, when used topically, which means on the outside of your body, you will know whether you’re allergic or not. You can make the decision whether using a natural repellent that has two known compounds (the essential oil,and the carrier oil/alcohol) or using “using EPA registered repellents” that have who knows what in them work for you.
It’s important to remember that any substance, natural or synthetic, has its unique set of risks and benefits. Every material, whether DEET, a vitamin, air, water, fire or earth, must be handled with intelligence and knowledge.
The more I learn about the world around me, the less I understand how we humans developed the equation: “natural = safe in the subset of all conditions”.
If the EPA is so vigilent about protecting the public by relying on such “protective” legislation as FIFRA, how did DEET escape “testing” for so long?! DEET was never tested on children and infants (just like most products). Not long ago you could only buy “Muskol” with 95% DEET and there was little precautionary advice listed on the container! Some preliminary research, COMMON SENSE, and natural plant-based products is always safer than listening to “Big Brother” and his evil, greedy partner in crime, “Big Business”.