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The effectiveness of one or another chemical means of protecting cultivated plants from insect pests depends on the working qualities of the active substance that is part of the composition. When choosing an insecticide for the treatment of plantings, farmers and owners of small summer cottages pay attention not only to its effect on parasites, but also to the safety for crops. The properties of hexachlorane make it one of the most powerful poisons that must be used with caution.
Physical and chemical properties of HCH
A substance belonging to the chemical class of organochlorine compounds was first synthesized back in 1825. However, industrial production of hexachlorane began in 1949 in Japan, after the insecticidal effect of one of its isomers was confirmed.
HCH stands for the γ-isomer of hexachlorocyclohexane and has the following chemical formula - C6H6Cl6. Despite the fact that the substance contains eight stereoisomers, only one is characterized by insecticidal activity - lindane, which led to the use of hexachlorane for the control of insect pests.
The chemical is produced in the form of a crystalline powder that has a white color. It is poorly soluble in water, but good in acetone, alcohols and fatty oils. Hexachlorane is thermally stable and has low sensitivity to ultraviolet rays. The molecular weight of the substance is 290.8, and the solubility in water (at 20 ° C) is 10 mg / l.
Effects on harmful organisms
The isomer of lindane, which is part of the chemical formula of hexachlorane, is characterized by intestinal and contact action on parasites. In addition, due to the high pressure, lindane also has the properties of a fumigant, therefore, it acts as a deterrent against some pests, preventing them from settling on a cultivated plant.
The contact effect is manifested after a small amount of hexachlorane hits the parasite. The poison penetrates through the cuticle of the pest and with the current of hemolymph enters the nervous system of the insect, thereby causing paralysis. The first symptoms of exposure are manifested by a loss of coordination of movement and increased excitement, then the limbs of the parasite are affected, and death occurs as a result of the insect's inability to feed.
In the event that a chemical substance was introduced into the soil, it penetrates into the tissues of cultivated plants and demonstrates a systemic effect, protecting against damage by pests. The duration of such a protective effect does not exceed two weeks.
Preparations containing an active substance
Hexachloran has been used in insecticidal formulations in the following forms:
- Dusts. These powdered mixtures are intended for pollination.
- Aerosols for use in the form of smoke and mist.
- Powder mixtures to be diluted with water.
- Insecticidal pencils and ointments.
The choice of a specific formulation depended on the type of insect pest and the economic feasibility of its use. Today the chemical has been discontinued because it poses a great danger to human health. It was replaced by a new generation of insecticidal preparations, which are not so toxic to humans, animals and insects.
In the past, hexachlorane-based insecticides have been used to kill gnawing moth caterpillars and other insect pests that live deep in the ground. Also, farmers used similar chemicals to decontaminate the premises where the crops will be stored and scare off parasites.
Zarechny Maxim Valerievich
Agronomist with 12 years of experience. Our best summer cottage expert.
The popularity of hexachlorane in the past is due to its high toxicity to insect pests, however, due to the danger to humans, its use was stopped.
Insecticides not based on hexachlorane, provided that they are used in the specified standards, do not have a negative effect on cultivated plants, do not lead to burns and do not stop their growth and development.
In the case where the chemical was used to treat the seeds before sowing, germination stimulation was observed. However, if the recommended consumption rate is exceeded, it will lead to deformation of the sprouts.
Since the chemical is quite dangerous to human health, all work with it must be carried out in protective equipment. The contact of drops on the skin is prevented with the help of work clothes, and a respirator is worn to avoid the penetration of vapors into the respiratory tract. After finishing work with hexachloran, it is necessary to take a shower with soap and wash all clothes in which the processing of cultivated plants was carried out.
Now drugs based on this substance are prohibited for use, and there is an explanation for this:
- if the soil is treated with hexachlorane, planting tuberous plants intended for consumption into it is permissible only after 4 years, otherwise there is a high risk of complications for human health;
- it is allowed to release agricultural animals for grazing on areas that have been exposed to a chemical substance no earlier than a month after use;
- carrying out such work as loosening without harm to human health is possible after 14 days.
Such long waiting times made the use of hexachlorane impractical, especially since it was replaced by new chemicals with improved characteristics.
What is compatible with?
The use of preparations based on hexachlorane is not recommended with alkaline chemicals and lime, as this reduces the working qualities of the insecticide. In other cases, a test is recommended.
How to store it correctly?
Since the substance is characterized by a high degree of toxicity, closed outbuildings are selected for storage, away from residential buildings. They must be locked to prevent access to the chemical by children and pets.