If your chickens have mites, use permethrin! No, if your chickens have mites use DE!
Have you heard this argument before? If you follow any chicken keeping page on social media then you have been exposed to this argument. The proponents of either method can be very strongly opinionated to say the least. Some can be flat nasty with some name calling, belittling, and insulting. If you chime in with a question that even has the pretense of a challenge they will tell you to get educated on the subject. I decided I would do just that, give you facts, and let YOU decide what is best for your flock.
What is DE?
DE is diatomaceous earth. Great. What the heck is that? DE “is a naturally occurring, soft, siliceous sedimentary rock that is easily crumbled into a fine white to off-white powder. Diatomaceous earth consists of fossilized remains of diatoms, a type of hard-shelled algae.” (Wikipedia)
DE is used commercially for many different things including a filtration medium for pool filters, as a mild abrasive in items such as toothpaste and polish, in some insecticides and pesticides (Kansas State University Research and Extension), and in many other commercial and industrial settings from the food industry to agriculture.
There are different types of DE and it is important to understand the difference. DE used for filters and other commercial applications of that sort is composed of crystalline silica. This is due to a process where the amorphous form of the DE is heated to a high heat and a fluxing agent is introduced, converting it to crystalline silica. Food grade DE is composed of amorphous silica, which simply means that the DE has no definable shape. We’ll come back to why these differences are important in a moment.
What is Permethrin?
“Permethrin is an insecticide in the pyrethroid family. Pyrethroids are synthetic chemicals that act like natural extracts from the chrysanthemum flower.” (National Pesticide Information Center)
While DE has many general uses, permethrin is used specifically as an insecticide. It is used in some commercial food settings and in some medications for the treatment of scabies.
How do they actually work?
Permethrin is a neurotoxin in insects, causing an interruption in the normal function of the sodium channels. Because it is poorly absorbed through the skin of mammals and because it reacts differently to the sodium channels in humans it does not have this same effect on humans.
DE, in theory, works by causing an abrasive action against the exoskeleton of small insects causing them to become dehydrated and die. However, DE loses its effectiveness once it becomes wet.
So why the hub bub?
I believe that the biggest factor driving the current debate surrounding DE and permethrin centers around a growing divide in this country between those who believe in natural alternatives to the chemicals that have become so prevalent in growing crops, treating animals, and treating humans. This same debate can be seen in the anti-Monsanto rallies and legislation popping up around the country.
Another factor that may be driving this is a social media driven distrust of anything with a chemical name. Many people, either through dishonesty or ignorance, create memes for FB and other social media that uses scary sounding chemical names and pictures with food products that contain the chemical name in the ingredient list. When you see them it is easy to be sufficiently frightened by something seemingly bad and so it is shared over and over again. In some cases there is some merit to the memes but in most cases it is simply hype to generate a share. You know the old saying, I read it on the internet so it must be true (I think it was Will Rogers that said that? Or maybe he said the newspaper……) At any rate, the numbers of memes of this sort are growing and more and more of them are popping up in my feed. The distrust of companies using chemicals of any kind is consequentially growing just as rapidly.
In this case, does a chemical name equal a bad chemical for you to use?
Are Permethrin and DE safe?
I’m sure that the main reason you are reading this article is not to hear me expound on my theories surrounding internet memes. You want to get down to the nitty gritty. Is either option safe for my family or my animals? Let’s take a look at the MSDS sheets and some scientific facts about both.
As we mentioned earlier, DE comes in different forms with different levels of crystalline silica. This is very important to note when discussing the safety aspect of DE. DE with high levels of crystalline silica are considered to be potentially dangerous to inhale. Studies have shown that workers in the DE industry who were exposed to DE dust containing levels of crystalline silica above 1% over several decades had an increased incident of silicosis. Another study showed that “those exposed to natural DE for over 5 years had no significant lung changes, while 40% of those exposed to the calcined form had developed pneumoconiosis.” (Wikipedia in reference to a CDC report) DE is regulated by OSHA and food grade DE with levels of crystalline silica below 1% are considered non-carcinogenic according to the MSDS safety sheet. “This product has not been classified as a carcinogen by NTP or
IARC.” (Kelly Solutions MSDS) When selecting DE to use around your house, make sure that you only select food grade DE that is specifically labeled as having less than 1% crystalline silica. The SPCA of Canada in fact, lists only one approved brand of DE that meets their requirements for use around pets. “The only Brand Name product currently approved by COABC and OMRI (Organic Materials
Review Institute) for use in farm animal health care is Barn Fresh® (Absorbent Products Ltd).
This product is also registered as a reduced-risk biopesticide (#27265) with Health Canada’s Pest
Management Regulatory Agency.” (SPCA Canada)
As for environmental problems with DE, DE can contribute to dust in the atmosphere but for this to be necessary, it must be in quantities much larger than that of the average homeowner or farm owner’s purchase. When referencing its affects on dust in the atmosphere, literature is referring to large, natural deposits of DE found around the world. As food grade DE is simply a filtered form of natural DE it is not harmful to the environment if spilled on the ground. If spilled in a confined space it is recommended that the bulk of the product be cleaned up and removed from the confined space by someone utilizing a respirator in order to minimize dust in the confined space. DE does not accumulate in the water and is not harmful to plants.
It is highly recommended that when dealing with DE, the applicator wear an N95 particulate respirator and if in areas of high concentrations of dust, vented goggles. (Kelly Solutions MSDS)
Permethrin, as we previously mentioned, is a synthetic form of the natural extracts of the chrysanthemum blossom. It was first registered with the EPA in 1979. Permethrin is considered a neurotoxin and is considered safe for limited application in humans with a 1% formulation available over the counter and a 5% formulation available via prescription. However, permethrin that is available for treatment of yards and farm animals is of a much higher concentration ranging from 10% to 36.8%, based on permethrin items that I found for sale online. According to the MSDS, “Personal Protective Equipment (PPE): Applicators and other handlers must wear: long sleeved shirt and long pants, chemical-resistant gloves, such as barrier laminate or Viton®, and shoes plus socks. Follow manufacturer’s instructions for cleaning and maintaining PPE. If no instructions for
washables, use detergent and hot water. Keep and wash PPE separately from other laundry.” (Kelly Solutions MSDS) According to the EPA, “…the Agency classified permethrin as ‘Likely to be Carcinogenic to Humans’ by the oral route. This classification was based on two reproducible benign tumor types (lung and liver) in the mouse, equivocal evidence of carcinogenicity in Long- Evans rats, and supporting structural activity relationship information.” (EPA) However, according to most medical sources, topical permethrin, when applied in the amounts and percentages recommended, have almost no absorption making topical applications safe for humans.
The effects of permethrin on the environment include harmful effects on bees, other beneficial insects, cats (due to long term processing of the chemical), and particularly fish (both fresh and saltwater). The MSDS says that, “This pesticide is extremely toxic to fish and aquatic invertebrates. For terrestrial uses, do not apply directly to water, or to areas where surface water is present or to intertidal areas below the mean high water mark. Do not apply when weather conditions favor drift from target areas. Do not contaminate water by cleaning equipment or disposal of wastes. This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow to drift to blooming crops if bees are visiting the treatment area”. (Kelly Solutions MSDS) According to the National Pesticide Information Center, “When permethrin gets into surface water like lakes or streams, it sticks very strongly to sediment and can stay there for more than a year. Since permethrin sticks to sediment and does not mix well with water, it won’t usually contaminate groundwater). (NPIC) The good news is that permethrin has a low toxicity in birds, with exception to aerosolized forms due to other chemicals in the aerosol. (NPIC Technical Data Sheet)
Overall Risk/Benefit Analysis
As for safety in humans, with appropriate measures taken, neither permethrin or DE appear to be of a high concern. When handling either, an N95 particulate mask is a must. When handling permethrin or when in areas of high concentrations of DE dust, goggles are required. No gloves are required to handle DE but appropriate chemical resistant rubber gloves are a must for handling permethrin.
Both food grade DE and permethrin are acceptable forms of topical and foliar insect control. While internal ingestion of food grade DE has limited to no effect as an anthelmintic, many farmers still use DE in both livestock and poultry feed as an anti-caking compound as it is approved for ingestion and remains inert throughout the digestive tract as there are no chemicals to be absorbed by the GI tract. Permethrin should only be applied in a topical setting or sprayed or dusted on to crops. However, the risks to beneficial insects and honey bees makes wide spread application dangerous and contributes to a mass decline of bees and other pollinators.
Risk Analysis in Poultry Specifically
As a small scale application to livestock and poultry, permethrin appears to be safe when labeled directions are followed due to its low toxicity in birds and the rapid elimination from the GI tract of humans. When applied to poultry, permethrin should be carefully controlled to mitigate risks to other animals.
DE, when applied to chickens, is not in itself harmful in a topical setting, however, the dust formed by DE when kicked into the air in a confined space such as a coop, could cause respiratory issues in chickens due to a particularly sensitive respiratory system. Unfortunately, most to all of the data available about the effects of DE on chicken’s lungs is anecdotal, as I was unable to locate any actual studies regarding this. As chicken and human respiratory systems are different it is very hard to extrapolate data from humans to chickens in this particular instance. Because DE is ineffective once it gets wet or in environments above 85% humidity and due to the potential effects on the chicken’s respiratory system, DE may not be a good choice for long term insect control on poultry.
My personal takeaway:
Although I am hesitant to use permethrin frequently, in a serious mite, lice, or tick infestation in my flock I have, and would, again use it. I noted no ill effects on the flock, the infestation was quickly and effectively controlled, and with good bio-security measures in place we have had no additional infestations to date. Due to the ineffectiveness once wet as well as the low efficacy of DE, the risks of respiratory problems from the use of DE has ruled it out for us when dealing with our chickens. I have used it in our kennels after their use but not during.
The use of DE or permethrin is a personal choice that you must make for yourself, your family, and your animals. I realize that some people will be so vehemently opposed to one or the other that any consideration of the opposing side may not be an option for them, regardless of the facts. Some people are so distrusting of anything chemical that regardless of the known data surrounding permethrin they will choose to never use it, risking the loss of their poultry to an infestation. On the flip side of the coin, some are so against the idea of a natural alternative that may mark them as a “hippie” that they will continue to douse their animals in any chemical touted as the latest and greatest with no regard for its effectiveness, safety, or long term effects. My hope is that those with an open mind will read this article, check the links for themselves, and come to their own conclusion without coercion, fear-mongering, name calling, or derision. I hope that I have presented the facts accurately for both sides of the argument so that both sides are fairly represented and people can draw an informed conclusion.
Have a great day and God bless!
Disclaimer: The information in this article is for educational purposes only. It is not the intention of this article to replace professional medical or veterinarian advice. Before using any product on yourself, others, or animals, consult your primary care physician or your veterinarian.
National Pesticide Information Center (Permethrin)
Kelly Solutions MSDS (DE)
Kelly Solutions MSDS (Permethrin)