The effectiveness of a particular chemical means of protecting cultivated plants from insect pests depends on the working qualities of the active substance included in the composition. When choosing an insecticide for treating crops, farmers and owners of small summer cottages pay attention not only to its effect on parasites, but also to its safety for crops. The properties of hexachlorane make it one of the most powerful poisons that must be used with caution.
Physico-chemical properties of HCH
A substance belonging to a chemical class 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 to combat insect pests.
The chemical is produced in the form of a white crystalline powder. It is poorly soluble in water, but soluble 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 its solubility in water (at 20 °C) is 10 mg/l.
Effect on harmful organisms
The lindane isomer, which is part of the chemical formula of hexachlorane, is characterized by intestinal and contact effects on parasites. In addition, due to high pressure, lindane also has fumigant properties, so it has a repellent effect on some pests, preventing them from settling on the cultivated plant.
The contact effect occurs after a small amount of hexachlorane hits the parasite. The poison penetrates the cuticle of the pest and enters the insect’s nervous system through the hemolymph current, thereby causing paralysis. The first symptoms of exposure are manifested by loss of coordination of movement and increased agitation, then the limbs of the parasite are affected, and death occurs as a result of the fact that the insect cannot feed.
If a chemical is introduced into the soil, it penetrates into the tissues of cultivated plants and exhibits a systemic effect, protecting against pest damage. The duration of such a protective effect does not exceed two weeks.
Preparations containing the active substance
Hexachlorane has been used in insecticidal preparations in the following forms:
- Dusts. These powdered mixtures are designed for pollination purposes.
- Aerosols for use in the form of smoke and fog.
- Mixtures in powder form that must 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 use. Today, the chemical has been discontinued because it poses a great danger to human health. It has been replaced by a new generation of insecticidal preparations that are not so toxic to humans, animals and insects.
Application
In the past, hexachlorane-based insecticidal preparations were used to kill cutworm caterpillars and other insect pests that live in the soil at fairly great depths. Farmers also used similar chemicals to disinfect premises where crops would be stored and to repel parasites.
Insecticidal agents not based on hexachlorane, provided they are used in the specified standards, do not have a negative effect on cultivated plants, do not cause burns and do not stop their growth and development.
When the chemical was used to treat seeds before sowing, germination was stimulated. However, if you exceed the recommended consumption rate, this will lead to deformation of the sprouts.
Security measures
Since the chemical is quite dangerous to human health, all work with it must be carried out in protective equipment. Contact of drops with the skin is prevented by using work clothes, and a respirator is worn to prevent vapors from entering the respiratory tract. After finishing work with hexachlorane, it is necessary to take a shower with soap and wash all the clothes in which the cultivated plants were treated.
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 in it is permissible only after 4 years, otherwise there is a high risk of developing complications for human health;
- it is permitted to release agricultural animals for grazing into areas that have been exposed to chemicals no earlier than a month after application;
- Carrying out work such as loosening without harm to human health is possible after 14 days.
Such long waiting times made the use of hexachlorane impractical, especially as new chemicals with improved characteristics replaced it.
What is compatible with?
The use of hexachlorane-based products is not recommended with alkaline chemicals and lime, as this reduces the performance 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.
