Pyrethrin - Wikipedia
Define pyrethrin. pyrethrin synonyms, pyrethrin pronunciation, pyrethrin Tell a friend about us, add a link to this page, or visit the webmaster's page for free fun. Pyrethrins are natural insecticides produced by certain species of the chrysanthemum plant. The flowers of the plant are harvested shortly after blooming and are. Pyrethrin, also known as pyrethrum, is a compound extracted from the chrysanthemum flower — a plant native to northeastern Europe, Asia and Eastern Africa.
Pyrethrins and pyrethroids interfere with the way that the nerves and brain function.
If you get a large amount of pyrethrins or pyrethroids on your skin, you may get feelings of numbness, itching, burning, stinging, tingling, or warmth that could last for a few hours. You are not likely to be exposed to amounts of pyrethrins or pyrethroids by breathing air, eating food, or touching anything that would cause enough pyrethrins or pyrethroids to enter your body and cause other problems. But if very large amounts of these chemicals were to enter your body, you might experience dizziness, headache, and nausea that might last for several hours.
Larger amounts might cause muscle twitching, reduced energy, and changes in awareness. Even larger amounts could cause convulsions and loss of consciousness that could last for several days. Allergic reactions have been seen in a few individuals who used products that contain pyrethrins or pyrethroids.
There is no evidence that pyrethrins or pyrethroids cause birth defects in humans or affect the ability of humans to produce children. There is evidence from animal studies that pyrethrins and pyrethroids might be capable of causing cancer in people, but the evidence comes from animals that ate very large amounts of pyrethrins or pyrethroids for a lifetime.
To protect the public from the harmful effects of toxic chemicals and to find ways to treat people who have been harmed, scientists use many tests. One way to see if a chemical will hurt people is to learn how the chemical is absorbed, used, and released by the body; for some chemicals, animal testing may be necessary. Animal testing may also be used to identify health effects such as cancer or birth defects.
Without laboratory animals, scientists would lose a basic method to get information needed to make wise decisions to protect public health. Scientists have the responsibility to treat research animals with care and compassion. Laws today protect the welfare of research animals, and scientists must comply with strict animal care guidelines.
Animal studies show effects of pyrethrins and pyrethroids similar to those seen in people exposed to very high amounts of these chemicals. In addition, exposure to pyrethrins or pyrethroids might affect the ability of some animals to reproduce and may also cause cancer. This section discusses potential health effects from exposures during the period from conception to maturity at 18 years of age in humans.
Children exposed to large amounts of pyrethrins or pyrethroids would be expected to be affected in the same manner as adults.
ATSDR - Public Health Statement: Pyrethrins and Pyrethroids
If children were to get a large amount of pyrethrins or pyrethroids on their skin, they might get feelings of numbness, itching, burning, tingling, or warmth that could last for a few hours. If very large amounts of these chemicals were to enter a child's body, the child might experience dizziness, headache, and nausea that might last for several hours.
Even larger amounts could cause muscle twitches, tremors, convulsions, and loss of consciousness that could last up to several days. Pyrethroids might be able to penetrate the skin of infants and young children more easily than the skin of adults. Infants and young children are more easily dehydrated than adults through exercise, flue, colds, and the conditions that contribute to fluid loss. Therefore, pyrethroids that penetrate the skin may become more concentrated in internal tissues of the young.
There is no evidence in humans that pyrethrins or pyrethroids cause birth defects. Some young animals showed signs of possible damage to the body's defense system that fights infection after their mothers were exposed to pyrethroids while their babies were developing in the womb. There is some indication that the developing brain of some very young animals could be affected by pyrethroids.
If your doctor finds that you have been exposed to significant amounts of pyrethrins or pyrethroids, ask whether your children might also be exposed. Your doctor might need to ask your state health department to investigate.
Pyrethrins and Pyrethroids
Pyrethrins and pyrethroids are effective insecticides that are often used in household sprays, aerosol bombs, insect repellents, pet shampoos, and lice treatments. Using products containing these compounds will expose you to these chemicals.
If you decide to use these products, carefully follow the instructions on how to apply them properly and how long to wait before re-entering the treated area. Do not apply more than the recommended amount. Pesticides and household chemicals should be stored out of reach of young children to prevent accidental poisoning. Always store pesticides in their original labeled containers; never store pesticides in containers that young children would find attractive, such as old soda bottles.
If you feel sick after a pesticide has been used in your home, call the local poison control center or see a doctor.
Keep your poison control center's number next to the phone. If a close neighbor or someone living nearby is applying pyrethrins or pyrethroids, you may want to remain indoors with your children and pets in order to avoid being accidentally exposed to these chemicals.
Certain pyrethroids, such as permethrin, phenothrin, and resmethrin, are sprayed to control mosquitos during the spring and summer. Remaining indoors and closing your windows while your neighborhood is being sprayed will lessen your exposure. Since these compounds frequently are used on crops, they are often detected in fruits and vegetables. Make sure you wash fruits and vegetables thoroughly before eating them.
Trim the fat from meat and poultry because pesticides often concentrate in fat. These compounds are often detected in soils, especially in agricultural areas.
Some children eat a lot of dirt. You should discourage your children from eating dirt. Make sure they wash their hands frequently and before eating. Discourage your children from putting their hands in their mouths or any other hand-to-mouth activity.
What's the difference between pyrethrins and pyrethroids?
Methods exist that can detect pyrethrins and pyrethroids in blood and urine. Because these compounds are broken down in the body quickly, there are also ways to measure the metabolites of these chemicals in human blood and urine.
These methods are not available in a doctor's office because special equipment is required. However, a sample taken in a doctor's office can be shipped to a special medical laboratory, if necessary.
These laboratories are usually located at research universities or affiliated with government agencies such as the Centers for Disease Control and Prevention CDC.
Your doctor may need to contact the county health department for a list of laboratories that can perform these tests. Because pyrethrins and pyrethroids break down in the body rapidly, these methods are useful only if exposure has occurred within the last few days.
At this time, these methods can tell only if you have been exposed to pyrethrins or pyrethroids and cannot tell if you will have any adverse health effects. Methods also exist that can measure the concentration of pyrethrins and pyrethroids in air, water, soil, and foods. The NPIC telephone number: Chapter 7 contains more information regarding the measurement of pyrethrins and pyrethroids in humans and environmental samples.
The federal government develops regulations and recommendations to protect public health. Regulations can be enforced by law. Recommendations provide valuable guidelines to protect public health but cannot be enforced by law.
Regulations and recommendations can be expressed in not-to-exceed levels in air, water, soil, or food that are usually based on levels that affect animals; then they are adjusted to help protect people. Sometimes these not-to-exceed levels differ among federal organizations because of different exposure times an 8-hour workday or a hour daythe use of different animal studies, or other factors.
Recommendations and regulations are also periodically updated as more information becomes available. For the most current information, check with the federal agency or organization that provides it.
Some regulations and recommendations for pyrethrins and pyrethroids include the following: OSHA regulates the level of pyrethrins in workplace air. The EPA has recommended daily oral exposure limits for 10 different pyrethroids. These limits range from 0.
In September ofthe EPA issued a request to pesticide formulators to voluntarily change the term "inert ingredients" to "other ingredients" on pesticide labels because the general public often believed that inert ingredients meant harmless ingredients.
Since federal law does not define inert ingredients on the basis of toxicity or hazard to humans, it should not be assumed that all inert ingredients are nontoxic. The EPA publishes a list of all inert ingredients used in currently registered pesticides, but it does not specify which ingredients are contained in any specific formulated product. For more information on regulations and guidelines, see Chapter 8.
Toxicological profile for Pyrethrins and Pyrethroids. If you have questions or concerns, please contact your community or state health or environmental quality department or: The finer powder produced is better suited for use as an insecticide than the more coarsely crushed flowers.
However, the more coarsely crushed flowers have a longer shelf life and deteriorate less. Pyrethrins delay the closure of voltage-gated sodium ion channels in the nerve cells of insects, resulting in repeated and extended nerve firings. This hyperexcitation causes the death of the insect due to loss of motor coordination and paralysis.
Together, these two compounds prevent detoxification in the insect, ensuring insect death. Pyrethrins are effective insecticides because they selectively target insects rather than mammals due to higher insect nerve sensitivity, smaller insect body size, lower mammalian skin absorption, and more efficient mammalian hepatic metabolism. Observations in food establishments demonstrate that flies are not immediately killed, but are found more often on windowsills or near doorways.
This suggests, due to the low dosage applied, that insects are driven to leave the area before dying. As pyrethrins and pyrethroids are increasingly being used as insecticides, the number of illnesses and injuries associated with exposure to these chemicals is also increasing. Additionally, they have little lasting effect on plants, degrading naturally or being degraded by the cooking process. Similarities between the chemistry of pyrethrins and synthetic pyrethroids include a similar mode of action and almost identical toxicity to insects i.
Pyrethrins have shorter environmental persistence than synthetic pyrethroids because their chemical structure is more susceptible to the presence of UV light and changes in pH.
It should be noted that they pose a toxic hazard normally not found in commercial pyrethroid to mammals and humans. While pyrethrum extract is composed of 6 esters which are insecticidal, the semi-synthetic pyrethroid is a composed of only one chemically active compound.
As a result, the liver has to break down these additional chains first, which allows the toxicity levels to rise within the bloodstream, which can lead to hospitalization and even death. Therefore the use of pyrethrin in products such as natural insecticides and shampoos increases the likelihood of toxicity in mammals that are exposed.
Medical cases have emerged showing fatalities from the use of pyrethrin, prompting many organic farmers to cease use. One medical case of an year-old girl who used shampoo containing only a small amount 0.
Prolonged exposure aggravated her respiratory tract cause by the compound in the shampoo, causing the girl to suffer from an acute asthma attack, from which she died two-and-a-half hours after first exposure to the shampoo. In the USA, the use of pyrethrum in home bug sprays ie. Pyrethrum toxicity[ edit ] Exposure to pyrethrum, the crude form of pyrethrin,  causes harmful health effects for mammals.
Pyrethrum also has an allergenic effect that commercial pyrethroids don't have. Exposure to even low doses may lead to toxicity in some cats.