Diatomaceous Earth Research What Is Diatomaceous Earth? We Have Seen Many Explanations for What Diatomaceous Earth Is

Diatomaceous Earth Research What is Diatomaceous Earth? We have seen many explanations for what Diatomaceous Earth is. But we know that Diatomaceous Earth (aka D.E.) is basically the deposit of Diatoms which died and settled to the bottom of seabeds and rivers. These Diatoms formed layers of rock deposits which are mined for use in everything from animal feeds to industry. The Rocky Mountain Livestock Journal said, “Millions of years ago, in all the waters of the earth, microscopic one-celled plants called diatoms took the minerals from the waters and created protective shells for themselves." These diatoms photosynthesize, combining oxygen, the most available element on Earth, and silica, the second most available element on Earth. "Diatoms once lived in quantities far beyond the mind’s ability to conceive, and as they died their shells drifted to the bottom of the seabeds. In this manner, vast deposits of diatom shells were laid down.” National Geographic Magazine said, “They come from inner space and are essential to life on this planet. Single-celled algae, diatoms by the trillions produce oxygen by photosynthesis, support the oceanic food chain, and help mankind do a host of industrial chores.” “More than twenty-five thousand species of diatoms, and no shell the same. Each a living jewel.” Diatoms were discovered in 1702 by a pioneer of Microscopy, Anton van Leeuwenhoek. He at first thought they were tiny animals. It was later that scientists concluded that because they photosynthesized, they were indeed plants and not animals. Several years later, German Microscopist J.D. Mooler, spent 15 years mounting over 4,000 diatom species on a single slide. There is evidence that the Chinese began adding D.E. to their animal feeds some 5,000 years ago. Further, various countries in Europe have been adding D.E. to the animal feed for many years now. There are many variations of D.E. deposits, as we will learn later in this section, consisting of many different species of diatoms. The diatoms in any given deposit will give that deposit certain characteristics, causing it to greatly differ from other deposits. Many things contribute to the quality of the D.E. as well.

Is D.E. a Safe Product for Animals and Humans? That all depends on who you ask. To us, it is extremely safe, other than being dusty. But we use a special type of D.E. We just simply put on a dust mask when using it. I have seen some folks say it will kill chickens if they are allowed to dust themselves in it. The only way that we can agree with that theory is if the user has chosen to use a D.E. that is not certified as “Food Grade”, "Codex", "Fossil Shell Flour", or "Amorphous" and they are using it in an enclosed area with poor ventilation. If you think about it, doesn't it make common sense that breathing a naturally occurring product that has been categorized as a Group 3 substance by IARC, would be less harmful than breathing chemical dust or fumes from a product that is not naturally occurring? A Group 3 is "not classifiable as to its carcinogenicity to + humans." Read below what The IPM Practitioner William Quarles said on the subject: It is titled : DIATOMACEOUS EARTH FOR PEST CONTROL “Both swimming pool grade and natural diatomaceous earth come from the same fossil sources, but they are processed differently. The natural grades are mined, dried, ground, sifted and bagged. The pool grade is chemically treated and partially melted and consequently contains crystalline silica which can be a respiratory hazard. Thus, it is imperative that only natural diatomaceous earth be used for insect control. This non-crystalline silica is not a hazard as the human body apparently can dissolve it." “Ingestion of diatomaceous earth is not toxic to mammals. Rats fed a daily diet containing 5% freshwater diatomaceous earth show no abnormalities after 90 days (Bertke 1964). Dairy farms sometimes feed their animals food containing 1 to 2% diatomaceous earth to control worms and other internal parasites (Allen 1972). The Food and Drug Administration, Department of Health, education and Welfare, sets “tolerances” on poisonous chemical insecticides because residues of these insecticides are known to cause cancer and other alarming physiological effects when introduced into the bodies of test animals. The Department of Agriculture in Michigan said in a letter, “Our animal pathologist has examined the vital organs and intestinal components submitted, both macroscopically and microscopically, and has found no visible evidence of organ abnormalities. These components consisted of brain, thyroid, rib section, lung, heart, liver, true stomach, small intestine section, large intestine section, pancreas, kidney, bladder, and forestomach. These organs were submitted under affidavit as being from a slaughtered dairy cow having free choice access to fossil shell flour for approximately five years.” The University of Arkansas did a study to determine whether the addition of diatomaceous earth was harmful to chickens. Their conclusion, “It posed no threat.” What is a Tolerance? "A “tolerance” is the maximum amount of any certain poison, which can legally be found in any certain foodstuff intended for human consumption. The amount of poison which can legally appear in any type of foodstuff is established by the Food and Drug Division of the United States Department of Health, Education, and Welfare by Bio-Assay. (Some states impose even more rigid rules) Tolerance limits vary all the way from “zero” to many parts per million and are frequently changed as new information becomes available. Impoverished humans add “Fossil Flour” to their baked goods in order to stretch their flour supply (Cummins 1975). It is so safe for use on food that the FDA has exempted diatomaceous earth from requirements of fixed residue levels when added to stored grain (Fed. Reg. 1961). The U.S. EPA also allows its use in food storage and processing areas (Fed. Reg. 1981). The only possible health effect comes from long-term chronic exposure to quantities of the inhaled dust. Current maximum U.S. exposure standards are 6 mg/m3 of dust containing less than 1% crystalline silica (Pestline 1991). Calcined diatomaceous earth poses the greatest problem. For instance, rats showed little reaction when their lungs were exposed to 5-80 mg of naturally occurring diatomaceous earth, but a strong reaction to diatomaceous earth that had been calcined (heated to 800 C) (Swensson 1971)." They further go on to say, “Marine diatomaceous earth has enough crystalline silica in it that mining can cause health problems. Diatomite from this source may produce a distinct type of pneumoconiosis, the term applied to any abnormality in the lungs resulting from the inhalation of dust (Abrams 1954).” What About Silicosis? “Silicosis refers to lung contamination and irritation by crystalline or free silica (SiO2). Crystalline describes the orientation of the SiO2 molecules, which occur in a fixed pattern in contrast to the nonperiodic, random molecular arrangement defined as amorphous. Exposure to free silica is an occupational hazard to workers.” Perma-Guard, a refined fraction of diatomaceous earth, is the only insecticide product on the market which is totally exempted from these tolerance requirements. This is true because Perma- Guard is an inert mineral dust of natural origin and contains no Synthetic Chemicals whose residues can find their way into your body to cause cancer and other diseases. What is Crystalline or Free Silica? The USGS says, "Crystalline silica is the scientific name for a group of minerals composed of silicon and oxygen. The term crystalline refers to the fact that the oxygen and silicon atoms are arranged in a three-dimensional repeating pattern." They go further saying, "The compound silica (SiO2 ) is formed from silicon and oxygen atoms. A chemical compound is defined as a distinct and pure substance formed by the union of two or more elements. Because oxygen is the most abundant element in the Earth's crust and silicon is the second most abundant, the formation of silica is quite common in nature. The silica sand, just mentioned as the substance used to derive pure silicon, is made of quartz, which is the most common form of silica found in nature. Silica can also be biological in origin, produced by tiny organisms. The most significant of these are diatoms (plants) and radiolarians (animals), both of which extract silica from the water around them to form their structures or shells. For both organisms, silica is a nutrient they must have to survive. In nature, they use the dissolved silica that originates from sedimentary rocks at the bottom of a lake, river, or ocean. Thus, silica can be found in more than one state— amorphous as in the remains from a diatom and crystalline as in a quartz crystal. Both are SiO2 , but they are quite different physically. What's more, silica in its crystalline state is found in more than one form. This phenomenon is called polymorphism (literally "many forms"). Silicates constitute the most abundant class of minerals. Geologists regard silicate minerals as the basic materials out of which most rocks are created. We mentioned that the compound silica, which is formed by the chemical reaction of silicon and oxygen, can be either crystalline or non- crystalline. Depending upon the extremes of temperature and pressure it has been subjected to or, in some cases, the speed at which it cooled, a solid can take on different forms. Diatomite, described earlier, and quartz are identical chemically (both SiO2 ) and both are solids at room temperature, but their physical forms-and their internal structures-are very different." "In a crystalline substance (such as quartz), the atoms and molecules make up a three- dimensional repeating pattern. The pattern unit is repeated indefinitely in three directions, forming the crystalline structure. This is similar to floor tiles, in which a two-dimensional pattern unit, say one made of two black tiles and four white tiles, is repeated indefinitely in two directions. This repeating pattern can be altered. It would be possible to change the positions of the two black tiles and four white tiles in relationship to one another and still have a pattern that could be repeated indefinitely in two directions, but the resulting design would be different. Likewise, the internal structure of the crystal can be changed and the resulting crystalline substance would be changed." "Now, picture the black tiles and white tiles, still in the same relative proportions of two to four, randomly placed on the floor, forming no pattern whatsoever. Such is the structure of a non- crystalline, or amorphous, substance. A diatom is an example of silica in a non-crystalline state. Some amorphous materials exhibit short-range ordering of their atoms. Using the analogy of the floor tiles one last time, suppose the two black tiles and four white tiles formed a pattern, and it was a pattern governed by some sort of rule, but it was not a repeating pattern. The distinguishing feature of a crystalline substance is that you can take any portion of it and see the whole. With a non-repeating pattern, you can't do that. Some short-range orderliness may exist, but no predictable order extends over a long distance. Scientists call this state glassy. Not surprisingly, window glass, which forms when molten glass is quenched, is an example of silica in a glassy state. It is not crystalline because it cooled too rapidly for the atoms to arrange themselves into a long-range periodic structure, but it contains short-range ordering that many amorphous materials do not possess. Glassy and amorphous materials are considered to be synonymous by many scientists because both are non-crystalline." Define Amorphous. Amorphous is a term that describes a "solid which is not crystalline" according to the Chemistry Dictionary. Merriam-Webster's dictionary describes Amorphous as "Without a definite shape or form; shapeless. What does D.E. have in it? Boy that is a loaded question. D.E. differs as much as we do. Here is what Wally Tharp the president of Perma-Guard said in an Acres U.S.A. interview: “There are a great many deposits in the United States. They vary greatly in age and quality of material. Also because there are a number of species of diatoms, each having its own unique shape and skeletal arrangement, there are a great many differences in physical forms when viewed under a scanning electronic microscope. When you examine diatomaceous earth under the electronic microscope you can readily see these differences and also get an idea of the various impurities and the extent of skeletal deterioration of the deposit. Thus we find that there are only three deposits that I know of that are suitable for our purposes. Many of the others are salt water deposits and are of no value to us.” The IPM Practioner said, “Whether marine or freshwater fossils are better for insect control work has been recently debated. Freshwater fossils met with early commercial success, and are easier to apply without clumping or caking. Any diatomaceous earth with a large oil absorption capacity, though, is a candidate for use as an insecticide. Ideally, it should be a high purity amorphous silica of a uniformly small particle size, that contains very little clay, and less than 1% crystalline silica.” In Natural Food & Farming Magazine, Jaynen Kemp Cockrell said this: “Their exact composition will vary, depending on what mineral concentrations are in the waters where they are formed, In general, most samples will contain the following elements: silicon, sodium, boron, strontium, vanadium, gallium, titanium, aluminum, manganese, magnesium, iron, calcium, copper and zirconium. There can also be trace amounts of lead and arsenic which may not exceed 20 ppm if the resulting D.E. is to be used as a food grade additive.” In our simple way of thinking, this all means that all diatomaceous earth product vary greatly depending on if they are freshwater or marine type diatoms. They also vary based on the waters content where they originated. And lastly, they differ in size, shape and manner in which they were treated during processing. What are the Types of D.E.? Some D.E. products mix D.E. with pyrethrins to boost its insect killing properties. One type that is proven harmful to animals and humans is Flux-Calcined D.E. which has been heated to 800 degrees and forms Crystalline or Free silica. This is the type used in many insecticide grade and pool grade D.E. products. There are fresh water and salt water types as well. Salt water types are referred to as marine types. Fresh water types are referred to as Amorphous. Is There Really that much of a Difference in D.E. Products? Yes there certainly is. This is the area that most critics make their mistake. They will say that D.E. is dangerous, but usually quote the information from the crystalline form and not even mention the findings of the non-crystalline form. Because diatoms form in any water and sometimes even on land, their diversity is unmatched. Due to this, one can find himself or herself using a low quality D.E. or one that can be very harmful to them and their animals. Because of water currents, most deposits of diatoms can be very impure, some even dangerous. There are over 25,000 varieties of diatoms, having different sizes and shapes. The mineral content of the deposits vary a great deal, as water currents mix all kinds of foreign materials, some, such as Arsenic, being dangerous or deadly. The shapes of the diatoms are important as well. Some cigar shaped diatoms can actually stick in the lungs or organs of the animals causing major problems. The D.E. we use and recommend consists of cylinder shaped diatoms with a lattice like shell that looks much like a sieve. Hardness is also a concern because many if not most D.E. deposits are inferior. Many are softer and therefore won’t be nearly as effective. Our D.E., Perma-Guard, has a hardness factor of 7 on a scale that puts a diamond at a 9. This hardness factor allows the diatom particle to abrade the waxy outer coating or cuticle on an insect’s body and absorb its body moisture, and this same hardness is what works in the intestine of the animal that consumes it. Pressure from excess earth or rock can also cause some deposits to become free silica and raise the crystalline silica to hazardous levels. What Made us Choose Perma-Guard? Because we wanted something safe to use around the house and on the animals, we knew there was no option except something “Food Grade.” The only challenge we had after that was to determine which “Food Grade” product was the best. For the answer to this question, we merely looked at how the manufacturer backed up their product. Perma-Guard was the only company we found that backed it up unconditionally. Here is their guarantee: “Perma-Guard has a 100% satisfaction guarantee. After 30 days, if the buyer was not totally satisfied, they are guaranteed an immediate refund in full. Perma-Guard also carries a $1,000,000 product liability policy that covers both user and distributor.” Well, we here at the farm use only “Food Grade” or “Codex” freshwater (Amorphous) diatomaceous earth from Perma-Guard. Perma-Guard is the original, oldest, and most experienced company carrying D.E. In 1962, Perma-Guard, with the help of Arizona State University, was granted a patent for the use of D.E. to be added to animal food. Until the patent expired, this company held the exclusive right to sell D.E. for that purpose. West of the Mississippi, there are over 600 deposits of D.E. The vast majorities are useless. In fact, the Perma-Guard company only knows of four deposits that meet the FDA requirements to be called “Food Grade.” So even if it says “Food Grade” on the package, that doesn’t mean it is of the highest quality. In fact, most are inferior due mostly to impurities or hardness. We personally checked out all the information about D.E. and after looking at Material Safety Data Sheets and reading about 100 publications and documents, Perma-Guard beat every other D.E. product hands down. International Agricultural Laboratories, Inc physicist, Carey Reams says in summary, “All of the elements in Perma-Guard D.E. are so enjoined into either a cheated or colloidal form until they appear to work in unison with each other rather than as individual elements. Thinking of them as individual elements is quite misleading. None of these elements found in Basic Perma-Guard are considered poisonous.” In the Rocky Mountain Livestock Journal in January/February 1996 issue, Janet Sands writes: “Perma-Guard insecticides have passed exhaustive tests, many of them under the scrutiny of the U.S. Dept. Of Agriculture, Kansas State University, and the Food & Drug Administration (FDA). Over the years these products have scored dramatic successes in protecting stored grain and seed, growing crops, homes and industrial plants from insect infestations, without the addition of any chlorinated organic phosphates, systemic poisons or chemical compounds commonly found in almost all commercial insecticides.” With a money back guarantee and a guarantee against damage, why consider any other product? To this day, there has never been a claim for damages. During my research, the only potential lawsuit I have seen was after a dairyman tried FSF with great satisfaction, then bought a cheaper product from a trucker, and had his business destroyed. Some of his cows died from arsenic poisoning, the milk was contaminated and could not be sold. He wanted to sue Perma-Guard because he did not know who else to sue. All he had was a ticket from a dime store sales book, with no name, address or phone number. Perma-Guard acquired a sample of the material and was amazed at the amount of arsenic. Of course, he realized there was no claim against Perma-Guard, took bankruptcy and went out of business. The sad thing is that the trucker probably had no idea that he was selling a dangerous product. He, like many other people, take the attitude that ALL DIATOMACEOUS EARTH is the same. The poor dairyman found out the hard way. The trucker may never have known. The World Health Organization cautions that D.E. with a crystalline (free) silica content over 3% is dangerous for ingestion by humans or animals. Perma-Guard D.E. has less than 1% free silica. Swimming pool D.E. ranges from 60% to 70% free silica. There are very few deposits of D.E. that meet these free silica minimum standards. Now you know why, after deciding that D.E. was useful for us, we chose to use Perma-Guard “Codex” D.E.

Does D.E. Really Work? Well, that is a matter of who you ask. Some say it doesn't. But the first question I ask them is, how long have you used it? Then I would ask questions like, "How did you use it?" "What kind of D.E. did you use?" "Do you know the difference between the types?" If you ask us, we say it does. We have seen many letters from farmers and hobbyist who swear by its use. They claim everything from parasite control to lower mortality rates in their animals. Here at the farm, our mortality rate has dropped dramatically. You see, we are after results. We don't really care how the results come, but more that they come. We have put together some of the letters and emails from different people so you can see what other people say about the use of Fossil Shell Flour in and around their animals. What are People Saying About D.E.? “I have been actively engaged in training some of the finest walking horses in the country for the past 15 years. I take pride in the appearance and health of the horses under my care, which have won many national awards against stiff competition. I am constantly on the alert for products I feel can improve their health and condition. I am grateful to have found FOSSIL SHELL FLOUR and here is why: It stopped scours, noticeably reduced flies, increased appetites, better feed conversion, eliminated internal parasites and created a healthier appearance. I would definitely recommend this product to other horseman.” Leslie “Shorty” Thomas, Trainer—L. Frank Roper Stables—Winter Garden, Florida.

"We were losing one sheep every three days from the fringe tape worm in the bile duct. We started feeding the animals Fossil Shell Flour, mixed with salt and cotton seed meal. Within two weeks, the dying stopped. Since that time we have lost 2 sheep, but not from worms. To say I am sold on Fossil Shell Flour is a rank understatement. I suggest to anyone, 'JUST TRY IT. IT DOES NOT COST MUCH!" Johnnie Firestone.

"D.E. contains 15 trace minerals important to animal diets. D.E. mixes well with all feeds while guarding against insect damage. Prevents worms and virus epidemics from developing. Saves albumen, destroys harmful acids, safeguards the stomach. Improves health and growth of young animals. Causes better digestion, allowing animals to absorb a higher percentage of protein from its regular diet." Dr. Phillip Schaible, former head of the Department of Poultry Sciences of Michigan State University.

"Feeding FSF to my show and race horses, stallions, mares, foals and horses in training, we have seen improvements in their hair coat and their attitude. Flies and parasites are less of a problem." Dan Miller, Capital South Syndicate

"I have used for about 5 days now and my SL Wyandotte is now up off of her hocks and I no longer give her the Colife. As a matter of fact, after the first day I quit giving her the Colife because I could not tell which chick had the problem. It took me about a half hour to really examine them to figure out who had the problem. Thanks so much for everything." H. in FL.

"My birds are doing great on your supplements." S. in CA.

"When we saw the miniature horses, they were a pretty sad lot. The amount of lice and other parasites were overwhelming. After using Perma-Guard, the external parasites, including the lice, just turned to dust. It was great! We also have been using the diatomaceous earth for nutrient absorption. This was a major concern because our horses were so terribly underfed when we purchased them. We are seeing marvelous results in the rib covering and quality coat already. Thanks again for introducing us to your products. They will become a permanent part of our program." K from AZ

"I wanted to write and express my enthusiasm for Perma-Guard products. We have noticed many benefits on our farm. We use the Fossil Shell Flour as a feed additive for our birds and dogs. We began using it when we had a problem with buffalo gnats biting the birds on the face and neck. I know of an ostrich that died from gnat bites, and I did not want the same fate. We could not get rid of them by any chemical means, and then we tried Perma-Guard in the barn, on the birds, and on the sandy dusting areas where they dust themselves. I was astounded, the very first time I used it. Since we have been using Fossil Shell Flour feed additive for the ostriches, we have noticed several beneficial effects. One, the stools are consistently good looking, and have less odor. Two, flies usually lay their eggs in feces, but the feces now contains D.E. and the flies are either not able to survive landing on the feces, or the fly larvae are not able to escape contact with the D.E. In our barn areas we are now virtually free of flies, gnats, fleas, black flies, love bugs, mosquitoes, mites, etc. Thanks for introducing me to such a fine and economical product. My farm will never be free of Perma-Guard products." C. from AL

"FSF is given "free choice" to calves at 36 to 48 hours after birth. The calves readily consume it, even at this young age. In a very few cases, FSF is placed in the mouth so that they acquire a taste for it. Following this they eat it on their own. FSF has been used on approximately 2,000 calves, the results have been consistent and gratifying. The incidence of calf scours has been 99% eliminated. There have been cases of Diarrhea, but this has been due to the baby calf overeating on milk. No true case of calf scours as such, has been observed. The reason for FSF doing such a commendable job of preventing calf scours, Pneumonia and white muscle disease, is due to the baby being provided with a well balanced complex of chelated minerals. Dr. Carey Reams, a respected Bio-Physicist held the view that practically all diseases were caused by a mineral deficiency and/or imbalance in the body. Our experience in our own herd of beef cattle has been that by using FSF we have been able to stop the use of vaccines and antibiotics. We also have abandoned the use of herbicides, pesticides and commercial fertilizers. All of the above practices have accomplished two things in our operation: 1. Healthier cattle; 2. A financial viable enterprise." Best Regards, H.D. Johnson DVM

"After reading several articles about the advantages of using D.E., we started what turned out to be a year long search for a supplier in AZ. We are pleased when we saw your ad and made our connection. We are feeding and dusting (feather duster) our 17 dairy goats, 2 llamas, 4 Barbados sheep, a burro, and a horse. We also dust the barn and pens daily after clean-up. The wet spots in the pens get a handful of D.E. after raking. Last year the raking turned up a host of fly larvae, this year there are practically none." M. in AZ

"I'm so pleased to be able to once again obtain Perma-Guard Diatomaceous Earth. The horses and dogs are fed D.E. daily. The goats and chickens are free-fed and love it. I also spread it in their pens. So good for the eradication of so many nuisance pests-and most importantly, they're safe for my animals." M.J. in AZ "I began feeding the D.E. to all my birds, three pounds to each 50 pound bag, and after six days use, I can really tell a difference in the fly population. I also spray the chick runs. I don't know why this product isn't publicized at ratite events. I could have saved a lot of money and man hours over the years with its use. Needless to say, I am very pleased with the product and will share the information with other ranchers." F. in NM

"Brian conducted fecal test samples to check for parasites after using diatomaceous earth for several weeks. His tests came out negative. Neither he nor his vet believed it, so they took more samples from different bison, from different herds which had been fed diatomaceous earth - negative. Not only did he solve his parasite problem with a non-toxic, natural product, but he found that the coats and overall appearance of his bison had improved. Another benefit is that some diatomaceous earth remains in the manure, preventing the eggs of flies and parasites from hatching out, thereby, breaking the cycle of re-infestation." Canadian Bison Association - Lori Wheeler

"In response to your question about possible hazard from including diatomaceous earth in the ration fed to dairy cattle, I can relate our experiences when it was incorporated as 2 percent of the total ration fed to cattle. It had no apparent harmful effect and there is no evidence that any of it is absorbed and no residue appeared in the milk. I trust that this is the information you desired." R.P. Link - Professor/Dept Head University of Illinois, College of Veterinary Medicine.

"We bought a carload of grain that was heavily infested and I anticipated a financial loss. However, we mixed it with D.E. as it went into the bin. After a few weeks, we re-cleaned the grain and found no live insects. The damaged grain was made into chicken feed, leaving us with a GRADE A grain to sell. Since we bought the load at a heavy discount, we made a good profit. After that, we deliberately sought out bargains in infested grain, and learned we could make more money that we could on paying the regular price on clean grain. After a few months of experimentation, we got completely away from the use of chemicals. There was no need to subject our customers, or our employees to possible contamination, especially when the Perma-Guard performed even better then conventional chemicals." Irv Manley

"My birds are so healthy it is just great. People who do not even know about chickens tell me what good looking birds I have!"

How We Use D.E. We personally use D.E. in the feed of every animal on our place. As an anti-caking agent, which is how D.E. is sold normally, it coats each particle of feed. It is the opinion of many that this allows more digestive juices to come in contact with the food particles, allowing the gut to better digest the food, resulting in better growth, and less undigested feed particles to pass. It is also believed by many that the D.E. which passes through the animals helps to control the fly population because when the flies lay their eggs on the manure, the larvae hatch and are lacerated by the D.E. This breaks the cycle of the fly. D.E. is also loaded with trace minerals as well. Here is the analysis of the D.E. we use here. Our chicks get it in their first feeder of feed. Our dogs get it in their feed weekly. We also put D.E. in the dusting areas for the birds. Our birds enjoy a good dusting with D.E. in the hot weather. Dusting helps to control parasites such as lice, and we believe D.E. aids in that control since lice are soft-shelled. We also put D.E. in the nest boxes to help control lice in the nests. In Conclusion Since we have used, Fossil Shell Flour we haven’t seen any of the so-called hazards that some folks claim will stem from D.E. usage. Some say that birds are more sensitive to dust than dairy animals. I think I would agree with that, but that doesn’t mean that Amorphous Fossil Shell Flour will cause them to be sick. Many of our birds are 5 years old. Most have had D.E. for all their lives, both in dust baths and in their feeds. So we think we are qualified to speak from a position of at least mediocre knowledge about D.E. One of the first things we learned about D.E. is there is a huge difference in D.E. products even those listed as “Food Grade.” Some of the same people who criticize D.E. work in the commercial poultry industry, or for chemical companies, or have never used it to any degree to see how D.E. will work for them, or they may have gotten inferior product and base their decision on that. Yet a good many of them say D.E. will cause respiratory problems. But consider this. What if the birds had a low resistance due to too many meds and repeated respiratory trouble before using D.E.? What if the D.E. they used was higher in free silica than the D.E. we use? What if the birds housing was poor with damp conditions and crowded? What if the coop has poor ventilation? What if the birds are carriers for Foul Coryza? What if you brought a bird in from someone else’s flock that you didn’t quarantine for several weeks, and it brought in something with it? What if you showed a bird at a show and it had to stand next to a sick bird for a weekend? What if that sick bird was a carrier of something that you now carry back to your flock? Ironically, some of the very same people who criticize D.E. have sold birds that are respiratory problem carriers. We know how that is. We have owned some of their birds in the past too. That is why we are selective where we get birds and advice from. All these questions are valid don’t you think? We do, that’s why we decided to look at D.E. objectively based on our own experience and draw our own conclusions. To break it down, we looked at and gathered all the information we could find on it. We decided we would be the best judge of what is proper for our flock and you would too. One other thing to consider, remember when people always said, “if you use D.E., wait until the chicks are feathered good before giving it to them or you will cause a problem?” I sure do and I have said it in the past myself. But a few years ago we decided, after talking to Wally Tharp at Perma-Guard, who has over 40 years experience with D.E., he told me that we could feed it from day one. So I decided to set up a little experiment. We started giving D.E. from the day the birds hatch and you know what? No harmful effects were seen. In fact this year, the birds seem even better than last year. If it were causing internal and respiratory trouble, as some say it will, wouldn’t you think that the chicks would show it first? Aren’t they even more susceptible to toxins? Wouldn’t it take less to kill them than it would to kill adult birds? If it were going to cause respiratory problems, wouldn’t it cause it in the chicks first? Don’t they have the smallest respiratory systems? So keep these questions in mind when you are reading up on and pondering if D.E. is for you or not. After all, you need to learn what program is best for you and your flock. You will find an enormous number of opinions out there, some based on experience and some based on theory. In the past when we have chosen to follow inexperience and theory, we have found that following experience would have been the better decision. Analysis for Perma-Guard D.E. Used Here at AMERICAN Health & Herbs MINISTRY Because Diatomaceous Earth is a natural product, analysis will fluctuate. This is typical. Aluminum 0.65 Boron 0.0023 Calcium (Ca), % 0.40 %CaO (calc. From %Ca) 0.55 Copper (Cu), % 0.0019 Iron (Fe), % 0.72 Magnesium (Mg), % 0.21

Phosphorus (as P205), % 0.037 %MgO (Calc, from %Mg) 0.34 Manganese (Mn), % 0.0052 Potassium (K), % 0.16 Sodium (Na), % 0.26 Strontium (Sr), ppm 59.9 Sulfate Sulfur (S), % 0.062 Titanium (Ti), ppm 420 Vanadium (V). ppm 43.8 Zinc (Zn), % 0.0022 Chlorides .074% or 740 ppm or .067 or 670 ppm

Silica (as SiO2)% 79.9 Fossil Shell Flour Typical Physical Properties Because D.E. is an organic product, some fluctuation in properties is expected. These are typical. Dry brightness (green filter) 88 Specific Gravity 2.0 pH 7.6 Oil Absorption (rub-out), % ASTM D281-84 112-116 Water Absorption, % 150 Apparent Density, loose, Scott Volumeter, lb/ft3 8-10 Wet Density lb/ft3 19-22 Surface Area, M2/g(N2BET) 26-28 Moisture (% max.) 4.5%

Typical Chemical Analysis for Fossil Shell Flour Chemical Weight Percent, Dry Basis

SiO2 93.0 Al2O3 3.0

Fe2O3 1.3 MgO 0.5 CaO 1.1

Na2O 0.6

K2O 0.3

TiO2 0.2

FDA listing—GRAS (Generally Regarded As Safe) Federal Register listing as having “No Tolerance” requirement. Complies with Food Chemical Codex Crystalline Silica content 0.36% to 1.12%

DIATOMACEOUS EARTH FOR PEST CONTROL By William Quarles The IPM Practitioner Monitoring the Field of Pest Management Volume XIV, Number 5/6, May/June 1992 Least toxic physical and chemical solutions are often part of an IPM program. Various forms of amorphous silica are commonly used as part of this strategy. Diatomaceous earth and silica gel are used in various physical formulations with or without added pesticide. The type of silica and the formulation depend on the target pest. In this issue advantages and disadvantages of diatomaceous earth are discussed. In July the merits and uses of silica gel will be outlined. Diatomaceous earth (DE) is a non-toxic insecticide that is used for protection of stored products, and to control pests of the home and garden. Organic gardeners like it because it is a natural product that poisons neither the earth nor people. Pest control operators (PCOs) like it, because diatomaceous earth can be used to treat wall voids and other inaccessible regions of a house in order to deny harborage to pest insects. Also, PCO's that use least-toxic products are able to address homeowner concerns about poisons in a positive way. Diatomaceous earth is obtained from deposits of diatomite - fossilized sedimentary layers of tiny phytoplankton called diatoms, many of them originating at least 20 million years ago in the lakes and seas of the Miocene (see Box A for more information on diatoms). The developing North American continent was full of these organisms that ingested dissolved silica and converted it into a highly ordered shell. Diatoms that lived in prehistoric seas are now mined mostly in Lompac, California as Celite ® and fossilized freshwater species are found in such places as California, Oregon, Nevada and Arizona (Cummins 1975). Whether marine or freshwater fossils are better for insect control work has been recently debated. Freshwater fossils met with early commercial success, and are easier to apply without clumping or caking. Any diatomaceous earth with a large oil absorption capacity, though, is a candidate for use as an insecticide. Ideally, it should be a high purity amorphous silica of a uniformly small (less then 10/µ) particle size, that contains very little clay, and less than 1% crystalline silica. The diatomite should be properly milled and ground, the diatoms well-separated, and if possible, physically intact (Katz 199aa; Calvert 1930; Allen 1972). Any product registered with the EPA has to meet the proper standards. This kind of material is easier to obtain from freshwater fossil sources because much of the marine diatomite is calcined (glassified by high temperatures) in order to improve its filtration characteristics (Calvert 1930). Calcined fossils are often sold for use in swimming pool filters. Such material has little absorptive power, and is not useful as an insecticide (see Common Sense Pest Control Quarterly 3(1):14-16). High temperature (800 degree C) also converts amorphous silica into crystalline silica, and some grades of diatomite on the market may contain up to 60% of this material. Crystalline silica, when inhaled can cause the deadly disease silicosis or other respiratory problems (Katz 1991a; Diafil 1992; Abrams 1954). Both silica gel and diatomaceous earth are forms of amorphous silica, and they both kill insects by desiccation, not by absorbing water, but by absorbing the oily or waxy outer cuticle layer by direct contact. When the thin (about 1/µ) waterproof layer of the epicuticle is lost, the insect loses water, then dies. Abrasive damage to the cuticle also leads to water loss in some cases, but the effectiveness of silica as an insecticide often depends on the amount of oil it can absorb. The ability to absorb oil or wax from an insect, is often, but not necessarily, related to surface area of the silica (Ebeling 1961). Silica gel has the advantage of a much larger surface area than diatomaceous earth, but the latter is more abrasive. Whether the one or the other is used depends on the target insect and conditions (Ebeling 1971). Diatomaceous earth was improved in 1976 with the invention of Dryacide®. The surface area of the silica was increased by gluing silica gel to it. Trials of Dryacide for wheat protection are discussed later. Another improved material is Shell-shock® invented by Dorsey Dunlap and tested by Robert Snetsinger at the University of Pennsylvania. Shellshock is diatomaceous earth covered with an adhesive that is formulated for control of insects such as cockroaches and ants. Once an insect comes into contact with Shellshock, it is unable to easily remove it. Lipids and fats are drained from the cuticle, and the insect dies from desiccation (see Common Sense Pest Control Quarterly 7(1):5-20). Though not used as often as silica gel inside houses, diatomaceous earth is most useful in treating cracks, wall crevices, wall voids, and attics to repel insects and deny harborage in these areas. It is effective against pests that live in close association with humans such as cockroaches, silverfish, mites, ants, houseflies, spiders, bedbugs, fleas and crickets (St. Aubin 1991). History of Use Soil and clay dust is often used by birds that take "dust baths" to free themselves of mites and other parasites. This observation may have led the Chinese to use diatomaceous earth (diatomite) for pest control 4000 years ago (Allen 1972). In America, road dust was observed killing cotton worms as early as 1880 (Stelle 1880). Until the 1950's clay dusts, sand, or silica gel were more popular test materials than diatomite. Insects controlled by inert dusts up to 1950 include oriental fruit moth and codling moth larvae, flea beetles, cucumber beetles, cockroaches, Mexican bean beetle larvae, and stored grain pests (Bartlett 1951). Marine diatomaceous earth was used in many of the early experiments. Pollivka (1931) used diatomaceous earth to suppress field populations of corn borer. Dusting the corn plants had a measurable physiological effect. Silking was delayed, and for every day's delay in silking, there was a reduction of 4% in the corn borer's population. Chiu BOX A. BIOLOGY OF DIATOMS Though diatomaceous earth is composed of fossilized diatoms, these small creatures have survived with few changes until today. Two major types exist, marine and freshwater. Freshwater diatoms were discovered by Leewenhoek in 1703 before the existence of marine organisms was even suspected. Systematic naming and identification began in 1819. Diatoms are all single-celled organisms, but some are free-living and others live in colonies. They are generally flat, composed of two overlapping valves made of porous silica with many small (.5 to 1µ) holes. The general construction is similar to that of a petri dish (Cummins 1975). The major species in freshwater fossil samples is the cylindrical Melostra granulata which is shown in the photo on the front page. It is 5 to 35 in diameter, and 9 to 26µ in height. Pores are 50 to 100 mµ in diameter (Calvert 1930). Diatoms are phytoplankton, actually small plants that are responsible for much of the food and most of the oxygen that is consumed on the earth. About six-tenths of all phytoplankton are diatoms, and the ocean averages 7 to 8 billion per square meter. Plankton diatoms divide once every 18 to 36 hours, and the life cycle of a diatom is about 6 days. Marine diatomaceous phytoplankton are often called "grass of the sea" because many ocean creatures depend on them for food. Masses of them are consumed in the food chain, as it takes 10,000 lb. of diatoms to make 1,000 lbs. Of coepeds, then 100 lbs. Of herring, and finally 1 lb. of tuna fish. Diatoms filter nutrients from solution, and photosynthesize, releasing oxygen. The product of photosynthesis is a dark-green fishy smelling oil that is chemically more similar to animal than vegetable oil. Diatom oil may be the source of today's petroleum. Diatoms represent the major way that silicates dissolved from the earth's crust are recycled. Quartz has a solubility of about 10 ppm, while amorphous silica averages around 100 ppm. River waters have about 5 to 35 ppm of dissolved silica. Solubility of silicates is low, but the ocean has 01 to 7 grams per ton of water. Diatoms extract silicic acid, and incorporate it into shell. When diatoms settle to the bottoms of lakes and seas, diatomaceous earth deposits are formed. This silica is often reintegrated under pressure into the earth's crust as sedimentary or metamorphic rock, usually a hard chert consisting of opal or chalcedony. Deposition rate is slow - 1 foot every 20,000 years. Freshwater deposits occur in streams, swamps, lakes and ponds. Marine deposits were in Moreno shales of the Upper Cretaceous, about 60-110 million years ago. The U.S. deposits occurred during the Miocene epoch, about 20-30 million years ago. Sedimentary deposits of diatoms are sometimes found in decaying bogs with other plant material. This association with decay led to the term kieselguhr (1808) for diatomaceous earth in Germany. The word comes from the German words kiesel (silica) and guhrer (to ferment). Most everywhere in English speaking countries the deposits are called diatomite. Diatomite was first discovered in America in 1839 in a bog near West Point, New York. It was discovered in California in 1852 near Sulsan Bay, 30 miles north of San Francisco. There are diatomite deposits throughout California, and the largest one is the marine deposit near Lompoc that is responsible for much of the filter aid sold under the brand name Celite™. The first commercial application of diatomite was the manufacture of dynamite in 1865 (Cummins 1975).

Table 1. Insects on Treated and Untreated Wheat* % Protection after 6 % Protection after 12 % Kernels Damaged Substance in ppm months months 15 mo.

P.Guard 2000 99.3 94.7 10 P.Guard 3500 99.4 96.3 6 P.Guard 5000 99.9 98.1 5 Cab-O-Sil 250 93.7 34.2 59 Cab-O-Sil 500 98.4 41.3 52 Cab-O-Sil 750 99.4 81.8 38 Malathion 92.2 71.3 30 Control 0 0 92 *%Protection = No. Insects in controls = No. insects in Treated/ No. in Controls x 100. Diatoms on Dry Grain When moisture content of the grain is low (e.g. 9.25%), and large enough concentrations of diatomaceous earth are used, stored products are protected better with diatomite than with a standard malathion treatment. Table 1 compares treatment with diatomaceous earth at 2000, 3500, and 5000 ppm with silica gel treatment at 250, 500, and 750 ppm and a standard malathion treatment of 1 pint 57% concentrate (0.63 lb. a.i.) per 1000 bushels. Tests were done in small (4 bushel) bins. Over a period of about six months there were five releases of about 15,000 stored product insects including: rice weevils, Sitophilus oryzae, confused flour beetles, Tribolium confusum; red flour beetles. T. castaneum; flat grain beetles, Cryptolestes pusillus; and saw-toothed grain beetles, Oryzaephilus surinamensis. The moisture content of the grain slowly increased during the year of the test from about 9% initially to about 13% at 12 months because storage was in open bins at about 50% relative humidity. Two kinds of diatomaceous earth, Kenite® and Perma-Guard® were actually used, but there was little difference between them. Each of the two silica gels, Cab-O-Sil® and Dri-die® SG-68 also gave similar results. Table 1 shows the results of repellency and damage assays performed on the stored wheat. Repellency was assayed by counting the total number of insects in either treated or untreated bins. Small numbers of insects mean large repellency or a large percent protection. After y months both silica gel and diatoms protected grain better than malathion. At 12 months, even the lowest concentration level of Perma- Guard gave dramatically better protection than malathion. Although this test seems to measure pure repellency, La Hue was more cautious and believed, "the comparatively small number of live insects in wheat treated with the diatomaceous earths throughout the storage may have been a result of killing action, of repellency, or a combination of both." Grain damage after 15 months was 5 to 10% with diatoms and 305 with malathion (LaHue 1967a). As can be seen from Table 1, silica gel did not protect as well as diatomaceous earth. Larger concentrations (750 ppm) though, obviously gave much better protection. In a later experiment La Hue (1970) showed that Cab-O-Sil at 1000 ppm was capable of giving slightly better protection to wheat (11.7% moisture) than either malathion or diatomaceous earth against the lesser grain borer, Rhnyzopertha dominica. The diatomaceous earth was applied at 3500 ppm and the malathion treatment was a standard application of emulsion at 0.63 lb. a.i./1000 bushels. Grain was almost completely protected from insect damage for 12 months. Mortality and Time As well as repellency and total amount of grain damage, toxicity as a function of timeis also an important variable. In this study of dry (9.25% moisture) stored wheat, grain samples from the bins were taken at various times throughout 12 months and live stored grain insect species were added to test mortality from the treated grain during a continuous 21-day exposure. As seen in Table 2, Perma-Guard at the highest concentration gave better 12-month protection than malathion for all insects tested. Diatoms were more effective against the rice weevil than the lesser grain borer or the confused flour beetle. Malathion gave the poorest protection against the confused flour beetle. Clearly, all insecticides were less toxic at longer storage times. Toxic effects drop off with time due to physical and chemical changes that occur when the dust is exposed to the atmosphere in a thin film (Ebeling 1973). Type of Stored Product Insect Carlson and Ball (1962) also used Perma-Guard to protect wheat against several different insect species. Wheat at either 12 or 14% moisture was treated with 0 to 7000 ppm of diatomaceous earth. Mortality of the insects (% that died) was assessed after two weeks of continuous exposure. The lesser grain borer, rice weevil, granary weevil, and saw-toothed grain beetle all had much greater mortality at the lower moisture level. In fact, 2% less moisture often meant 30% greater mortality. The treatment was most effective for hairy insects such as the flat grain beetle, rice weevil, and granary weevil, Sitophillus granarius; somewhat less effective for saw-toothed grain beetle, khapra beetle larvae, Trogoderma parabile; and lesser grain borer, Rhyzopertha dominica. Mortality rates were lowest for smooth-surfaced insects such as the confused flour beetle, and red flour beetle. At the highest rates of application (7000 ppm) and the low moisture, mortality was 90% or better for all insects except Trogoderma larvae (58%), confused flour beetle (5.6), and red flour beetle (12.8%). Mortality of confused flour beetle was very low in this experiment, but as we have seen in Table 2, La Hue observed high mortalities (nearly 100% at one year with 5000 ppm Perma-Guard) over long periods of time when the confused flour beetle was challenged with treated grain. One difference was that La Hue exposed the insects to treated grain for three weeks instead of two before assaying for mortality. More importantly though, the grain he used was drier at the start of the experiment. Initial grain moisture, then, is more important than the type of insect, and may be the most important factor in determining successful control of stored product insects with any particular diatomaceous earth or silica gel. The DE becomes ineffective in a moist environment, not because water fouls or saturates the absorptive surface, but because insects can constantly replenish their water loss by eating the moist grain.

Table 2. Mortalities from Malathion or Diatoms* Substance Insect % Mortality 6 mo. % Mort. 12 mo.

P. Guard 2000 adult rice weevil 100.0 57.4 P. Guard 5000 adult rice weevil 100.0 92.9 Malathion adult rice weevil 99.6 72.9 P. Guard 2000 c. flour beetle 93.6 39.2 P. Guard 5000 c. flour beetle 100.0 99.6 Malathion c. flour beetle 65.4 8.8 P. Guard 5000 lesser g. borer 93.2 92.0 Malathion lesser g. borer 99.6 59.6 *Mortality was assayed after a 21 day continuous exposure Table 3. Influence of Moisture on DE Repellency Treatment in Initial % % Protection in 6 % Protection in 12 Crop Reference ppm Moisture mo. mo.

Wheat 2000 9.25 99.4 94.1 La Hue1967a Wheat 3500 9.25 99.4 96.3 La Hue1967a Wheat 5000 9.25 99.9 98.1 La Hue1967a Wheat** 500 11.2 86.9 ---- La Hue1978 Strong & Sbur Wheat 2727 13.0 effective ineffective 1963 Wheat 3636 13.0 effective effective Ibid. Sorghum 1895 13.0 less than 0 less than 0 La Hue 1967b Corn 2151 13.4 zero less than 0 La Hue 1966 *% protection = number in controls-numbers in treated / number in controls x 100. **High temperature 33 °C (91.3 °F) storage Effect of Moisture As we see in Table 3, the initial moisture of the stored grain and the amount of diatomite used are two important factors in duration of protection. Diatomaceous earth was least effective for moist sorghum and moist corn. In both these cases, the initial grain moisture was more important than the relative humidity of the storage room. For the case of moist corn or sorghum, even when moisture decreased with time in dry storage, little protection was afforded. We also see from the Table 3 that even when the grain is somewhat moist, the effects of this can sometimes be overcome by the use of larger amounts of diatomaceous earth (DE). The corn started out with a high (13.4%) moisture content, but was stored in a low humidity atmosphere. Because of the low humidity "marked reductions occurred in the moisture content of the corn during the first 3 months of storage." The toxicity of the diatomaceous earth increased as the grain moisture decreased, but after one year about 42% of the treated corn kernels had been attacked, versus about 90% damage to untreated corn. The concentration of diatomaceous earth used (2151 ppm) was not large enough to overcome the large initial grain moisture despite a favorable low humidity storage (La Hue 1966). In general, mortality showed the same kind of decline with time seen with the repellency of the treated grain. In a toxicity test at one month, diatomaceous earth on corn killed 83.8% of the rice weevils, but was not very effective after this time. Few confused flour beetles were killed. After one month, the treated sorghum was largely ineffective against all insects tested in 21-day mortality tests. At one year the sorghum had been mostly destroyed by weevils. More weevils were in treated bins than controls because untreated grain had been eaten (La Hue 1967b). Initial Infestation and Adherency The situation for sorghum and corn was complicated by two other important variables - prior infestation and amount of adherency by the dust. The sorghum was infested with insects before it was treated, and DE does not adhere well to corn. Protection was a little better for corn, although the level of treatment was about the same as for sorghum, and the initial moisture levels were similar. Initial infestation is important because much of DE grain protection comes from repellency, and the most resistant beetles, such as the confused flour beetle, thrive on damaged grain. (Arbogast and Mullen 1988). When applied to corn, the DE did not adhere well to the grains, and accumulated in the bottom of the bins, so the upper layers were protected less well than lower layers. A later study verified that diatomaceous earth does not adhere as well to corn as it does the wheat or sorghum (La Hue 1972). Choice versus No Choice In most of La Hue's experiments there was an excess of food available for the weevils released in storage bins. The experimental set was thus choice tests - insects had a choice of treated or untreated grain. When an infestation is severe, and little food is available, the test situation is essentially a no choice situation, and hungry insects must eat treated grain. For example, when small amounts (2kg) of wheat (13% moisture) were treated with diatomaceous earth at 1818 ppm, and 3636 ppm, the minimum of about 2000 ppm that La Hue found was adequate to protect the grain no longer worked for long storage times. All rates of application worked equally well for 6 months, but differences started to show at 9 months. Only the 3636 ppm treatment was effective for a full 12 months (Strong and Shur 1963). USDA Storage Review Other experiments have also shown that diatomaceous earth protects stored products better than malathion. Large quantities of grain can be protected for up to three years. Dust concentration can be lower when storage is at higher temperatures. The type of silica gel or diatomite used seems to matter in some cases. Due to space constraints, this material will be reviewed in a future paper on silica gel (White et al. 1975; White et al. 1966, Quinlan et al. 1966; Redlinger et al. 1966; USDA 1967; La Hue 1978). Advantages and Disadvantages The advantage of diatomaceous earth treatment for stored products is that it is non-toxic, is easy to separate from grain merely by washing it, and could possibly be recycled in storage bins. Small amounts can also be safely protected. Beans stored in 100 lb. sacks can be protected by as little as 300ppm. Or one-half ounce (Allen 1972). About 1 cupful (625 ppm) of Perma-Guard per 25 lbs. Of grain is recommended by Universal Diatoms. With stored wheat, the plumpness, moisture content and other characteristics of the kernels, and the baking characteristics of the flour are unchanged by treatment (La Hue 1967a). Freshwater diatomaceous earth is so non-toxic that there are no established tolerance levels for residues on grain. On the other hand, silica gel is rated as a "foreign substance" by the USDA. Even though silica gel is more effective on a weight basis than diatomaceous earth, its use results in lower quality grading upon inspection by the USDA. Any wheat containing silica gel is automatically given the lowest grade - "sample grade." The disadvantage of diatomaceous earth treatment is that it reduces the weight per bushel of the treated product. This weight loss for dry wheat is about 4 lbs. Per bushel (a bushel weighs about 60 lbs.). The loss of weight is not due to water loss, but to a decreased bulk density of the treated grain. The dust adhering to the kernels affects the nestling and settling qualities of the grain, and it does pack as tightly. The problem is that weight loss per bushel is a USDA grading standard for determining grain damage from insects. Loss of weight per bushel means that the wheat is given a lower quality rating even if the total mass of the wheat is the same as it was before storage (La Hue 1967a). Both dusts are superior to malathion in that they do not leave toxic residues, and their protective qualities arise mainly from repellency. Malathion does not repel insects, but protects by killing them. The dusts exert less Darwinian selective pressure, and thus there is less chance for resistance to occur. Mode of Action A continuing controversy concerning the use of inert dusts is their mode of insecticidal action. Various theories have been proposed, but the consensus now seems to be that all the dusts kill not by poisoning or suffocation, but by desiccation. The outer wax or grease layer on the insect is lost to the dust either through abrasion or absorption. Since the insect then has no protection against water loss, desiccation occurs and the insect dies. For instance, when stored product insects were rolled in Perma-Guard for 10 seconds, then held in a dry environment for 24 hours, the treated lesser grain borer had twice the water loss of control insects and dies 3 times faster; the same result was shown for the red flour beetle. The confused flour beetle had a water loss of about 61%, and death was faster than controls (Carlson and Ball 1962). Ebeling (1971) found that "regardless of the period required to kill an insect species, death occurred when 28 to 35% of the body weight (about 60% of the water content) was lost." From La Hue's (1970) work we have seen that dry wheat can be protected about as well by treatment with 1000 ppm of Cab-O-Sil silica gel as by 3500 ppm Perma-Guard freshwater diatomaceous earth. For this application then, silica gel is about 3.5 times more effective by weight than diatomaceous earth. Part of the difference is due to adherence. About 73% of Perma-Guard applied at 3500 ppm to wheat adheres, whereas about 94% of the silica gel applied at 1000 ppm does. When the ratio is recomputed correcting for adherence, we find that silica gel is actually about 2.7 times more effective than diatoms (La Hue). La Hue did not publish the oil absorption capacity of the materials he used. A contemporary freshwater diatomaceous earth (Diafil) will absorb about 112-116% of its weight in oil (DiaFil 1992). The amount of oil taken up by diatomaceous earth was also measured on several German samples. The samples absorbed from 112 to 170% of their weight of peanut oil (Krezil and Wejroch 1936). According to Harry Katz (1991a), "silica gel can hold oil up to 300% of its weight. Fresh water diatoms can hold up to 114% of their weight in oil." If only oil absorption were important, we would expect silica gel to be about 2.6 times more effective than diatomaceous earth. As oil absorption capacity seems to be a good predictor of effectiveness in this case, the absorptive power of the diatomaceous earth seems to be more important than its abrasiveness, at least for the insects and conditions tested by La Hue (1970). Dryacide Silica gel is not useful for the treatment of stored products because its small particle size makes it difficult to use. It is also rated as a foreign substance when grain is graded. These disadvantages are overcome by the use of a patented process whereby diatomaceous earth is coated with silica aerogels. The silica gel coating is 0.1% (w/ w) the treated particles range from 20 to 50 /u and the product has a packed bulk density of 15 to 100 lb./ft 3 (Hedges and Bedford 1975). Dryacide is a gray dust that is 86% amorphous silica, 2% moisture, 8% clay, and 4% carbon from organic material in the original diatomite (Aldryhim 1990) (Since absorption power is increased by silica gel, a diatomite of lower purity can be used.) Tests of Dryacide for stored product protection found that populations of the rice weevil, lesser grain borer, and red flour beetle showed 100% mortality with use of 1000 ppm at 65% relative humidity and 20 degrees C. Mortality rates declined with increasing humidity. Dryacide treated wheat also prevented the adult development of almond moth, Ephestia cautella eggs. The 1000 ppm of Dryacide (1 g/kg) was easily removed either by washing or milling. Washed wheat contained less than 20 mg/kg, and milled flour from unwashed wheat contained less than 30 mg/kg. Residues larger than 100 mg/kg affect the quality of the wheat, including baking characteristics of the flour (Desmarchelier and Dines 1987). Further Tests Further tests were conducted on the granary weevil and the confused flour beetle at two different temperatures (20 and 30 degrees C) and two different relative humidities (40 and 60%). Dryacide was more toxic at lower relative humidities. The LC50 at 7 days for both species was less than 250 ppm at 40% R.H. regardless of temperature. At 60% R.H. the LC50 ranged from about 260 to 425 ppm. Toxicity measured at 2 days was 2.4 to 3.5 greater at lower relative humidities. Toxicity also increases with increased temperature, 2.9 times for the granary weevil and 1.3 times for the confused flour beetle. There was no adverse effect on wheat seed germination, or quality of flour and baked goods (Aldryhim 1990). GARDENS AND FIELDS Very few controlled studies of diatomaceous earth use in fields and gardens have been conducted. Even in these studies such basic information as the type of DE used is often omitted. In one field experiment diatomaceous earth (type and amount used not specified) was used as a physical barrier against the cabbage maggot, Delia radicum, in order to protect broccoli and Chinese cabbage. The treatment gave no protection, but it was applied late due to heavy rains, and had to be reapplied for the same reason (Matthews-G. and H. Goldstein 1988). Application of diatomaceous earth (infusorial earth, probably marine DE) to corn fields reduced corn borer, Ostrinia (Pyausta) nubialis, populations by 50%. Unfortunately, corn yields were reduced by the same amount, apparently because silking was delayed by the treatment (Polvika 1931). Mixtures of Derris (rotenone) and diatomaceous earth, or cryolite (Na3 AIF6) and diatomaceous earth were used to successfully treat beans and cabbage in field experiments against Mexican bean beetle (Turner 1946). A controlled study in 1943 found diatomite successfully reduced pea weevil populations (86% mortality). California cotton treated with DE had greater yields than fields treated with insecticide, but part of this effect may have been due to key fertilizer elements such as magnesium that are present in diatomaceous earth (Tucker 1978). Researchers at the University of Kansas Agricultural Experiment Station found that diatomaceous earth sprays were not very effective against cabbage looper, Trichoplasia ni, but that powder did somewhat better. When a pyrethrin-treated (0.2%) product equivalent to Diacide Homeguard® was used, however, cabbage looper, aphids, asparagus beetles, harlequin bugs and other insects was obtained. There were frequent applications because rain kept washing the DE away. The dust had very little effect on slugs (Wilbur et al. 1971). Diatomaceous earth may be effective in controlling aphids, brown mites, red spider mites, twig borers, oriental fruit moths, and codling moths in orchards or chalcid weevils in alfalfa. The major problem with outside use, other than possible toxicity to beneficials is the nuisance value of the dust. Four applications of 700 lbs/ac. may be necessary to maintain good control of chalcid weevils in alfalfa, for instance. The dust is extremely fine, and does not adhere well to foliage. It must be applied with an electrostatic applicator or shortly after plants have been moistened. Another reason diatomaceous earth may be impractical for field use is cost. When large areas are treated, it costs more than malathion. This disadvantage would not be a consideration for garden-size plots, of course (Ross 1981). Under field conditions insects are repelled by diatomite dust applied to row crops and orchards. Although bees tend to avoid treated blossoms, predators are killed by dust application. To minimize death of beneficials, diatomite should be applied late in the evening or at night. Although few controlled studies have been done, reports of garden use range from negative to wildly enthusiastic. "Users claim Thai diatomaceous earth is deadly to gypsy moth, codling moth, pink boll weevil, lygus bug, twig borer, thrips, mite, earwig, cockroach, slugs, adult mosquitoes, snails, nematodes, flies, corn worm, tomato hornworm, mildew and on and one" (Allen 1972). Negative responses have been either that it does not work, or that it killed released beneficials, such as lady beetles. One method for garden use is to spread DE on the ground in the spring, then till it into the soil. Supposedly, this controls mollusks and kills cucumber beetles, bean beetles, cabbage loopers, and tomato hornworms emerging from pupal stages. The repellency of the dust should be exploited through the use of barriers, when possible. Trees are protected by coating the ground around the tree base, painting the trunk with Tanglfoot®, and applying DE to the adhesive. This treatment reduces migration of Japanese beetle grubs and fruit fly maggots. As a snail barrier, a two-inch wide band a quarter-inch thick is spread around the area to be protected. The DE should be kept dry for best results (DeCrosta 1979). Diatomaceous earth can also be applied with a mechanical pump-type duster, or a humble applicator such as a plastic ketchup bottle. For small areas, Necessary Trading sells DE in a salt-shaker type of container. A dust mask and protective clothing should be worn when dust is applied. Another method is to add 1/4 lb. DE to a 5 gallon sprayer, then add a quart of warm water containing a teaspoon of flax soap, then top off with water and mix thoroughly. One part D in 3 to 5 parts of water has also been used. This mixture can be sprayed on trees and vegetation (DeCrosta 1979). One thing is sure, though, diatoms are less effective in hot humid weather. Control is better in areas with low rainfall. In one orchard where rainfall is less than 5 inches per year, damage was limited to 2% twig borer damage, and 2% from oriental fruit fly (Allen 1972). Though there is much anecdotal evidence that DE works for controlled garden pests, only one company has registered it with the EPA as an insecticide for use in the garden. It is usually sold in garden stores as a "horticultural helper." The pryrethrin-treated products, though registered for garden use, cannot be used for agricultural purposes (see Box B for registration information). New and Old Shellshock® overcomes the inherent repellency of diatomaceous earth by adding attractants. The original formulation was 66% fresh water diatomaceous earth with 34% attractants such as cane sugar, cornstarch, dextrin, molasses, and soybean mill feedings (Dunlap 1962). The new version of Shellshock has 855 DE and an improved adhesive (Dunlap 1992). A non-toxic insecticide for flying and crawling insects was prepared from 90% Celite, 8% skim milk, and 2% yeast extract. A fast knockdown of houseflies and mosquitoes was observed after spraying with this material (Carle 1985). An improved Dryacide for cockroach control has also been patented. Diatomaceous earth (302 grams) fine enough to sift through 200-400 mesh screen is treated with 400 grams of silica gel. The stabilized product is then mixed 1:1 (w:w) with powdered boric acid. When the product is spread at a rate of 2 g/m3, cockroaches are controlled within 7 hours (Belford 1990). A heavy application of DE dust to cattle can control cattle lice, Bovicola bovis. This approach might have to be used again if the organism becomes resistant to current control agents (Matthysse 1946). Household Use Diatomaceous earth and silica gel are both useful for pest management in dwellings. Cockroaches are especially sensitive to these kinds of desiccants, which is fortunate as they are becoming resistant to chemical pesticides. In a field test in Georgia, diatomaceous earth with pyrethrins (Diatect® - 0.2% pyrethrins, 1% PBO, DE 88%) was tested along with silica gel (DriDie® - 95.3% silica gel, 4.7% ammonium fluosilicate), and silica gel with pyrethrins (Drione® - 30% silica gel, 1.0% pyrethrins, 10% PBO, and 49% petroleum distillates). Boric acid, bendiocarb, diazinon, and chlorpyrifos were also tested in the same experiment. Dusts were applied with a .2kg Centrobulb duster (Central Robber Prod., South Salem, NY 10590). Heavy infestations (kitchens with more than 25 cockroaches visually sighted) in 40 homes were treated. Effectiveness data were determined after one treatment at roach hot spots in the kitchen. (Near or behind refrigerators greatest, wall cabinets next, floor cabinets least.) One application of pesticide was applied, then cockroaches were monitored by traps at 1, 2, 4, and 8 weeks. Cockroach populations were reduced by all treatments. The treated diatomaceous earth did not do as well as the other products. "Boric acid, chlorpyrifos, Drione, and Dri-Die did not offer in efficacy while all four produced greater mortality than bendiocarb, diazinon and Diatect." However, the time spectrum was slightly different among the most effective products. Chlorpyrifos and Drione brought about the quickest reduction in populations, 93 and 96%, respectively, after the first week. The effectiveness of the silica products dropped off somewhat with time. At 8 weeks DriDie showed a 54% reduction in population (initially 79%), and Drione showed a 78% reduction at 8 weeks compared to 96% at week one. The boric acid started off slowly, then improved in effectiveness with time. In the first week the reduction was 69%, but in weeks 2 through 8, reduction was constantly above 90%. Boric acid gave the greatest overall control throughout the test (Wright and Dupree 1984). A similar test compared Diacide® to Diacide with 0.2% pyrethrins and to Drione® for German cockroach control in kitchens and bathrooms of infested urban apartments in Virginia. Dusts were applied to cracks and crevices, wall voids, and inaccessible areas behind refrigerators and stoves. Sticky trap counts to monitor success were made, 1, 2, and 4 weeks after the test and compared with similar counts made before treatment. The insecticides with pyrethrins worked quicker, but there was no significant difference between the products when results were monitored over four weeks (Rambo 1992). When food and water is available, roach mortality is delayed. For instance, German cockroach populations exposed to 1 g/ft.2 of shellshock have 100% mortality in 24 hours when confined without food or water. When food and water is provided, 100% mortality takes 15 days. (Less than 20% of the controls are dead at this time.) The roaches' normal behavior is disrupted, however, and thirsty roaches spent 40% of their time at water sources, compared to 0.9% for controls. American, Oriental, and brownbanded cockroaches take 5 or 6 days for 100% mortality without food or water, and 13 to 18 days when water is available (Snetsinger 1988). Another problem is the diatomaceous earth repels roaches. Consequently, they are often flushed from treated areas, but not killed. One strategy is to treat cockroach harborage with diatomaceous earth to deny the insects a comfortable home, then kill those that are flushed out with a knockdown insecticide such as pyrethrins (Ebeling 1971; Katz 1991b). Another approach is to modify application methods or the product to reduce repellency. For instance, repellency is reduced if applied concentration is kept below 3 oz per 100 ft.2 (Katz 1991a). Attractants can also reduce repellency. Dorsey Dunlap's original DE insecticide contained molasses and sugar. His Shellshock does not repel American cockroaches exposed to a surface dusting of 2g/ft.2. Also, since Shellshock contains no toxic ingredients, its use in meat packing plants has been recently approved (Snetsinger 1992). Safety of Diatomaceous Earth Ingestion of diatomaceous earth is not toxic to mammals. Rats fed a daily diet containing 5% freshwater diatomaceous earth show no abnormalities after 90 days (Bertke 1964). Dairy farms sometimes feed their animals food containing 1 to 2% diatomaceous earth to control worms and other internal parasites (Allen 1972). Impoverished humans add "fossil flour" to their baked goods in order to stretch their flour supply (Cummins 1975). It is so safe for use on food that the FDA has exempted diatomaceous earth from requirements of fixed residue levels when added to stored grain (Fed. Reg. 1961). The U.S. EPA also allows its use in food storage and processing areas (Fed. Reg. 1981). The only possible health effect comes from long-term chronic exposure to quantities of the inhaled dust. Current maximum U.S. exposure standards are 6 mg/m3 of dust containing less than 1% crystalline silica (Pestline 1991). Calcined diatomaceous earth poses the greatest problem. For instance, rats showed little reaction when their lungs were exposed to 5-80 mg of naturally occurring diatomaceous earth, but a strong reaction to diatomaceous earth than had been calcined (heated to 800 degrees C) (Swenson 1971), Japanese workers chronically exposed to diatomaceous earth showed significant serum increases of the protease enzymes that correlate with emphysema (Omura 1981). Marine diatomaceous earth has enough crystalline silica in it that mining can cause health problems. Diatomite from this source may produce a distinct type of pneumoconiosis, the term applied to any abnormality in the lungs resulting from the inhalation of dust (Abrams 1954). ACKNOWLEDGEMENT The author wishes to thank Dr. Walter Ebeling for comments on the manuscript. REFERENCES: Abrams, H.K. 1954 diatomaceous earth pheumoconiosis. Am. J. Public Health 44-592-599. Adlryhim, Y.N. 1990 Efficacy of the amorphous silica dust, Dryacide® against Tribolium confusum Duv. and Sitophilus granarius (L) (Coleoptera: Tenebrionidae and Curculionidae) J. Stored Product Res. 26(4):207-210 Alexander, P., J.A. Kitchener and H.V.A. Briscoe. 1944, Inert dust insecticides. Part I. Mechanism of action. Ann. Appl. Biol. 31:143-9. Ibid. Part II. The nature of effective dusts, pp. 150-6. Ibid. Part III. The effect of dust on stored products pests other than Calandra granaria pp. 156-9. Allen, F. 1972. A natural earth that controls insects. Organic gardening and Farming 19 (Nov); 50-56 Arbogast, R.T. and M.A. Mullen. 1988 Insect succession in a stored-corn ecosystem in southeast Georgia. Ann Entomol. Soc. Am. 81(6):899-912 Bartlett, B.R. 1951. The action of certain "inert" dust materials on parasitic Hymenoptera. J. Econ. Entomol. 44(6):891-896. Belford, W. R. March 8, 1990. Insecticidal composition comprising boric acid and silica gel sorbed onto inorganic particles. Australian patent 594,539. CA 113:54369x. Bertke, E.M. 1964. The effect of ingestion of diatomaceous earth in white rats, a subacute toxicity test.. 6(3):284-91. Callenbach, J.A. 1940. Influence of road dust upon codling moth control. J. econ. Entomol. 33(5):803- 807. Calvert R. 1930. Diatomaceous Earth. American Chemical Society Monograph. Reprint 1976, University Microfilms, Ann Arbor, MI 251 pp. Carle, A. 1985. Insecticidal natural bait composition. Canadian patent 1,185,172. April 9, 1985. CA 103:33512s (1985). Carlson, S.D. and H. J. Ball. 1962. Mode of action and insecticidal value of a diatomaceous earth as a grain protectant. J. Econ. Entomol. 55(6):964-970. Chiu S.F. 1939a. Toxicity studies of so-called "inert" materials with the bean weevil, Acanthoselides obtectus (Say.), J. Econ. Entomol. 32(2):240-248. Chiu. S.F. 1993b. Toxicity studies of so-called "inert" materials with the rice weevil and the granary weevil. J.Econ. Entomol. 321(6):810-21. Cummins., A.B. 1975. Terra Diatomacea. Johns-Manville Co., Greenwood Plaza, Denver, CO. David, W.A.L. and B.O.C.Gardiner, 1950. Factors influencing the action of dust insecticides. Bull. Entomol. Res. 41:1-61. DeCrosta, A. 1979. Mother nature's bug killer. Organic Gardening 16(6):38-44. Desmarcheller, J.M. and J.C. Dines. 1987. Dryacide treatment of stored wheat: its efficacy against insects and after processing. Aust. J. Exp. Agric 27:309-12. DiaFil. 1992. CR Minerals Corp. 14142 Denver West Parkway, Suite 250, Golden, CO 80401. Driggers, B.F. 1928. Talc and mica dusts as a control for lepidopterous larvae. J. Econ Etomol. 21:938- 9. From Flanders 1941. Dunlap, D.S. 1982. U.S. Patent No. 1,321.258 March 23, 1982 CA XX195140h (1982). Dunlap, D.S. 1992. Personal communication. Ebeling, W. 1961. Physicochemical mechanisms for the removal of insect wax by means of freely divided powders. Hilgardia 30:531-564. Ebeling, W. 1971. Sorptive dusts for pest control. Ann Rev. Entomol. 16:123-158. Ebeling, W. 1973. Dust desiccants. Effect of prolonged exposure of films on insecticidal efficacy. J. Econ. Entomol. 66(1):280-282. Federal Register. 1961. (Nov. 1) 26,10228. Federal Register. 1981. (Nov. 10) 46, 55511-12. Flanders, S.F. 1941. Dust as an inhibiting factor in the reproduction of insects. J. Econ. Entomol. 34(3):470- 72. Hedges, K.B. and W. R. Belford. 1975. U.S. Patent No. 3,917,814. Insecticidal composition and method of preparing the same. Katz, H. 1991a. Desiccants: dry as dust means insect deaths. Pest Control Technol. April:82, 84. Katz, H. 1991b. Desiccants: high-stress vs. low-stress. Pest Control Technol. May:84, 88. ?? F. and H. Wejroch, 1936. The power of kieselguhr to take up oil. Seifensieder-Zig. 63:352-4, CA 30:7372(7) 1936. LaHue, D.W. 1966. Evaluation of malathion, synergized pyrethrum, and diatomaceous earth on shelled corn as protectants against insects in small bins. USDA/ARS Marketing Report No. 768, 10 pp. LaHue, D.W. 1967a. Evaluation of four inert dusts on wheat as protectants against insects in small bins. USDA/ARS Marketing Report No. 780. 24 pp. LaHue, D.W. 1967b. Evaluation of malathion, synergized pyrethrum, and a diatomaceous earth as protectants against insects in small bins. USDA/ARS Marketing Research Report No. 781. 11 ppg. LaHue, D.W. 1970. Evaluation malathion, diazinon, a silica aerogel, and a diatomaceous earth as protectants on wheat against lesser grain borer attack in small bins. USDA/ARS Marketing Research Repot No. 860. 12 ppg. LaHue, D.W. 1972. The retention of diatomaceous earths and silica aerogels on shelled corn, hard winter wheat, and sorghum grain. USDA/ARS Report No. 51-44. 8 pp. LaHue, D.W. 1978. Insecticidal dusts: grain protectants during high temperature-low humidity storage. J.Econ. Entomol. 71(2):230-232. Matthews-Gehringer, D. and J. Hough-Goldstein. 1988. Physical barriers and cultural practices in cabbage maggot (Deptera: Anthomytidae) management on broccoli and Chinese cabbage. J. Econ Ectomol. 8(11):354-360. Matthysse, J.G. 1946. Cattle lice: their biology and control. N.Y. Age. Expt. Sta. Bull. No. 832. 67 pp. Omura, T. et. al. Dynamic changes of protease inhibitors in workers exposed to diatomaceous earth dust (in Japanese). Arerugi 30(2):181. CA 95:85475t (1981). Parkin, E.A. and G.T. Bills. 1955. Insecticidal dusts for the protection of stored peas and beans against bruchid infestation. Bull. Entomol. Res. 46:625-41. Pestline, vol. 2. 1991 Occupational Health Services, Van Nostrand Reinhold, New York. p. 1138. Polivka, J.B. 1931. The effect of physiological changes in the corn plant on corn borer survival. J. Econ. Entomol. 24:394-5. Quinlan, J.K. and W. I. Berndt. 1966. Evaluation in Illinois of four inert dusts on stored shelled corn for protection against insects - a progress report. USDA/ARS Report No. 51:6. 20 pp. Rambo, G. 1992. 521 Dakota Drive, Herndon, VA 22070. Consultant to Diacide. Redlinger, L.M. and H. Womack, 1966. Evaluation of four inert dusts for the protection of shelled corn in Georgia from insect attack. USDA/ARS Report No. 51-7:25 pp. Ross, T.E. 1981. Diatomaceous earth as a possible alternate to chemical insecticides. Agric. and Environ. 6:43-51. Snetsinger, R. 1992. Personal communication. Snetsinger, R. 1992. Test results for Shellshock for EPA registration. Obtained by the author from Dorsey Dunlap April 12, 1992. Stelle, J.P. 1880. Road dust vs. cottonworms. Amer. Ent. 3:51-2. Cited in Bartlett 1951. St. Aubin, Forrest, 1991. Everything old is new again. Pest Control. Technol. June:50:52. 102. Strong, R.G. and D. E. Sbur. 1963. Protection of wheat seed with diatomaceous earth. J. Econ. Entomol. 56:372-4. Swenson, A. 1971. Experimental evaluation of the fibrogenetic power of mineral dusts. Stud. Laboris Salutis 10:86-97. CA 78:24845r(1973). Tucker, W. 1978. The good earth pesticide. New Times 2(21 Aug):29:35. Cited in Ross 1981. Turner, N. 1946. Diatomaceous diffluents for (insecticidal) dusts. J. Econ. Entomol. 39:149-58. USDA. 1967, USDA/ARS Preliminary Progress Report from the Marketing Quality Division, Oct. 1, 1967, pp. 32-42. White, G.D., W.L. Berndt, J.H. Schesser, and C.C. Fifield, 1966. Evaluation of four inert dusts for the protection of stored wheat in Kansas from insect attack. USDA/ARS Report No. 51-8, 22 pp. Wilbur, D.A., G. Swoyer, and A. Donahy. 1971. Effects of standardized diatomaceous earth on certain species of insects, Project No. 5203. Kansas Agricultural Experiment Station. Wright, C.G. and H.E. Dupree. 1984. Evaluation of German cockroach mortality with several insecticidal dust formations. J. Georgia Entomol. Soc. 19(2)216-223. Box B. Registration Information for Diatomaceous Earth Organic Plus® is a freshwater DE with no added insecticide. It has EPA registration for home and garden use on ants, cockroaches, fleas, earwigs, silverfish, boxelder bugs, beetles, and other crawling insects. It is also registered for use against slugs. Diacide Homeguard® is a freshwater DE with 0.2% pyrethins. It is registered for garden use in all states except California and New York. Perma-Guard D-10® is a freshwater DE registered for stored product use. Perma-Guard D-20® which has 0.2% pyrethrins, is registered for household use. Perma-Guard D-21® which has 0.1 pyrethrins is registered for garden use. Shellshock® is freshwater DE with added adhesive. It is registered for inside use against cockroaches and other crawling insects. No diatomaceous earth product is currently registered for agricultural use, although Diacide and Organic Plus are currently preparing the kind of studies necessary for this registration. Codex Codex Requirements Perma- Item Requirement guard Results

Arsenic (ppm) not more than 10 ppm <10 Lead (ppm) not more than 10 ppm <10 Non Siliceous not more than 25% on dried basis 11.0% Substance% PH passes test 7.3 Loss on Drying % natural powders not more than 10% 6.2 natural powders not more than 7% on the Loss on Ignition 3.8 dried basis