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Zinc PhosphideZinc Phosphide structure

When it comes to rodents like rats and mice and even pocket gophers, a worry often arises that a rodenticide may not be effective due to resistance. This often results in manufacturers and developers going back to the drawing board to come up with new formulas that mitigate the resistance affects and increase the power of poisons so that rodents are killed much quicker. One such poison which is regarded as the world’s most toxic rat poison is the active ingredient called zinc phosphide.

Solutions Pest & Lawn is proud to carry products containing this zinc phosphide. On this page, we will give you an overview of zinc phosphide, why it works so effectively and present to you the top zinc phosphide based products we have in stock for you to shop.

What is Zinc Phosphide?

Zinc phosphide (Chemical makeup: Zn3P2) is an inorganic compound that combines phosphorus with zinc. It is used in a number of rodenticide baits. When an animal consumes a bait with zinc phosphide in it, the acid in the animal's stomach transforms the zinc phosphide into phosphine. Phosphine is a gas which is highly toxic. Phosphine is also released by other chemical compounds such as aluminum phosphide and magnesium phosphide. These are used as fumigants in stored grain.

Zinc phosphide is used to control rats, mice, voles, ground squirrels, prairie dogs, nutria, muskrats, feral rabbits and gophers. The chemical is also utilized as tracking powder for the control of house mice. It is used on both agricultural lands and non-crop lands such as lawns, golf courses, highway medians, and areas in close proximity to wetlands. 

In its natural form, zinc phosphide is a heavy, finely ground, crystalline gray-black powder that is cannot dissolve in water and alcohol. Zinc phosphide has a long history, being first synthesized in 1740 and was first used as a rodenticide in 1911-12 by the Italians. It was not used in the U.S. as a rodenticide until 1939 when it was used as a substitute for strychnine, which was in short supply because of rodent control in Europe during W.W.II. Zinc phosphide has been registered for use in pesticide products in the United States since 1947. 

How Does Zinc Phosphide Work?

When zinc phosphide is consumed by either an animal or even a human, stomach acid causes it to release the toxic gas phosphine. Baits containing zinc phosphide are especially dangerous to animals that cannot vomit, such as rats, mice, and rabbits.

The phosphine in the stomach then crosses into the body's cells, and inhibits the cells from producing energy. This causes the cells to die. Zinc phosphide affects all cells, but targets cells in the heart, lungs, and liver.

Zinc phosphide works quickly as toxicosis usually is evident in 15 minutes to 4 hours following consumption of a toxic dose. The initial effects of consuming the poison is first loss of appetite and then escalates to convulsions, paralysis and eventual death. 

View our selection of zinc phosphide formulated products below. For more information about zinc phosphide or other active ingredients in our pesticides, please call us with your questions at 800-479-6583 or email us at askapro@solutionsstores.com.

How is Zinc Phosphide Used?

Zinc phosphide is only used as a rodenticide. It is made into bait that will attract the pest, such as gophers, ground squirrels, or field mice. There are over 80 products containing zinc phosphide registered for use in the United States.


The products containing zinc phosphide are used heavily in agricultural areas to control the rodent population which would damage crops. Zinc phosphide-laced baits have a strong, pungent phosphorus-like (garlic-like) odor that attracts rodents but makes the bait unattractive to other non-targeted animals .


Is Zinc Phosphide Safe To Use?

The EPA places zinc phosphide in Toxicity Category I, indicating the greatest degree of acute toxicity.The person most at risk of exposure is the handler of the pest control product. It is highly recommended to wear personal protective equipment required to lessen the risks of inhaling, ingesting or coming in contact with the skin. The minimum PPE suggested when handling strychnine based products includes chemical resistant gloves, eye protection, and dust masks.


An additional safety measure is to place baits in a tamper-resistent bait station to keep the bait from being tampered with by pets, non-target animals and children. We have a number of bait stations available at our store.


To learn more about rodent control and other methods of controlling rats and mice, visit our rodent control page

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