Pyrethrin - A Potent Naturally Occurring Insecticide
It might be surprising to some that one of the more effective insecticides is derived from natural sources and is not in fact a synthetic chemical. This pesticide is Pyrethrin, which is made from the seed cases of African Chrysanthemums. It is the byproduct of the refining of a sap like substance from the seed cases known as Pyrethrum. It was first discovered and isolated as an insecticide in 1924. Over 70% of the worldwide production of the plant that is refined to make the insecticide is grown in Kenya. Its production is a major source of exports for the Kenyan economy and accounts for nearly 4,000 jobs in Kenya. It is similar to the other insecticides in the pyrethroid family in that it is safe for humans and most other mammals.
The safety of insecticides such as Pyrethrin around humans is due in part to the method by which it kills insects. The insecticide blocks the flow of sodium atoms in the insect's nervous system, causing the nerves to continue firing, eventually overwhelming the insect's breathing and circulation.
The very properties that make it a deadly poison to insects make it safe for humans, because our nervous systems are not reliant on the same flow of sodium to operate. In addition, the much higher body mass of humans versus insects render it safe in the quantities generally used for pest eradication. Any amount of the pesticide that humans are exposed to is also broken down much more rapidly by the body than it is in insects, again rendering it virtually harmless.
The most common form in which Pyrethrin is sold is in sprays. It is usually sold in a diluted form, generally speaking making up less than 5% of the spray itself. However this is more than powerful enough to kill virtually any pests that are causing problems in a home. It can also be found in dusts and powders, which are meant to be walked through by the insect, leading to a fatal dose. Not only does it have a toxic effect on insects when they are exposed, it also has a beneficial repellent effect for those insects that might try to enter a treated area while the product is still active.
One possible drawback to using any product with this insecticide is that it has a very short half-life of only about 10 days. Thus it degrades quickly when exposed to the elements, and will not continue killing or repelling insects unless it is reapplied.
The safety of insecticides such as Pyrethrin around humans is due in part to the method by which it kills insects. The insecticide blocks the flow of sodium atoms in the insect's nervous system, causing the nerves to continue firing, eventually overwhelming the insect's breathing and circulation.
The very properties that make it a deadly poison to insects make it safe for humans, because our nervous systems are not reliant on the same flow of sodium to operate. In addition, the much higher body mass of humans versus insects render it safe in the quantities generally used for pest eradication. Any amount of the pesticide that humans are exposed to is also broken down much more rapidly by the body than it is in insects, again rendering it virtually harmless.
The most common form in which Pyrethrin is sold is in sprays. It is usually sold in a diluted form, generally speaking making up less than 5% of the spray itself. However this is more than powerful enough to kill virtually any pests that are causing problems in a home. It can also be found in dusts and powders, which are meant to be walked through by the insect, leading to a fatal dose. Not only does it have a toxic effect on insects when they are exposed, it also has a beneficial repellent effect for those insects that might try to enter a treated area while the product is still active.
One possible drawback to using any product with this insecticide is that it has a very short half-life of only about 10 days. Thus it degrades quickly when exposed to the elements, and will not continue killing or repelling insects unless it is reapplied.
