Benzene hexachloride

Benzene hexachloride (BHC) is an organochlorine chemical compound which is an isomer of gammaxene with the formula C6H6Cl6. As it is produced by the chlorination of benzene that’s why it is commonly known as benzene hexachloride. Although it is also known as Lindane or gamma – hexachlorocyclohexane (𝛾 - HCH). It has various other names as well such as gammaxene or Gammallin etc. Its IUPAC name is 1,2,3,4,5,6 – hexachlorocyclohexane.  Its production and agricultural use are banned in almost 182 countries. Although its pharmaceutical use is allowed in almost all the countries. 

Preparation of Benzene Hexachloride 

English scientist Michael Faraday synthesized benzene hexachloride for the first time in 1825. Although it was 1st isolated in 1912 by Dutch Chemist Teunis van der Linden. That’s why the compound is named after him.

It is prepared by light induced chlorination of benzene. In presence of UV light and heat, benzene undergoes addition reaction with chlorine molecules and gives lindane or benzene hexachloride. Reaction is given below –

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In this reaction benzene loses its aromaticity and changes into an alkane. Thus, in the reaction delocalization of pi – bonds in the benzene ring is removed by addition of chlorine atom to each carbon atom of benzene ring.  

Benzene Hexachloride Structure – C6H6Cl6

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Benzene Hexachloride Structural Formula 

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Lindane consists of six atoms of each carbon, hydrogen, and chlorine. C6H6Cl6 is the chemical formula of lindane. Chlorine and hydrogen atoms of lindane can stick above and below the ring randomly. Due to this it has a number of geometric isomers. Although it is not an aromatic compound and doesn't have a delocalized pi-electron system in the ring. Its isomers such as gamma – hexachlorocyclohexane (𝛾 - HCH), Gammexane etc. are used as insecticides. 

Properties of Benzene Hexachloride 

Properties of benzene hexachloride are as follows –

  • Its molecular formula is C6H6Cl6

  • Its molecular weight is 291g/mol

  • Its density is 1.89 at 66℉.

  • Its boiling point is 323℃.

  • Its melting point is 113℃.

Uses of Benzene Hexachloride 

Benzene hexachloride and isomers are used in various fields. Some of its uses are listed below –

  • It is used for pharmaceutical treatment of lice and scabies (or seven – year itch).

  • It is also used as an agricultural insecticide. Although presently its agricultural use is regulated or banned in many countries. During 1950-2000, 600000 tonnes of BHC was produced globally for agricultural use. 

  • It is used in medicinal shampoo or lotions. 

  • It is used for second line treatments of various diseases. 

  • It is used for seed treatment. 

Benzene Hexachloride Health Risks

According to the World Health Organization, BHC or lindane is moderately acutely toxic. This is the reason its usage in agriculture has been regulated or banned. Its higher amount can affect the nervous system and its production process is harmful for the environment. 

Large amounts of lindane can cause headache, dizziness, convulsions or even death in rare cases. It can affect the brain development of the child and can alter the thyroid hormone levels. At the level of 50 mg/m3 and above, lindane may cause immediate death or can be very dangerous for life and health. 

It is listed as one of the extremely hazardous substances in the list of extremely hazardous substances in the US. ‘International agency for Research on Cancer’ declared lindane a human carcinogen. Although WHO declared lindane as non – carcinogenic to humans but India’s BIS considered BHC a ‘confirmed carcinogen’.

It causes some adverse reactions which may cause seizures, skin irritation, itching, rash, burning sensation. These reactions of lindane make the skin very sensitive. It cannot be used for premature babies as it may cause severe neurotoxicity. 

Lindane pollutes the environment. It is termed as persistent organic pollutant or forever chemical. As it is a long lasting chemical in the environment. Its agricultural use is the primary reason for its presence in the environment. Through agriculture, it enters the food chains as well. The production process of lindane gives a large amount of toxic waste. According to studies, every ton of BHC production gives ten tons of toxic waste.  BHC in soil can leach to groundwater and can reach to the atmosphere by volatilization and therefore can be deposited by rainfall. 

Due to its agricultural applications a large quantity of lindane has been reported in the human body which is very dangerous for human health. 

Thus, lindane or BHC should be used vigilantly. All guidelines of the environmental protection agency and world health organization regarding lindane must be followed during its production and usage for a healthy environment and ecosystem.

This ends our coverage on the topic “Benzene hexachloride”. We hope you enjoyed learning and were able to grasp the concepts. We hope after reading this article you will be able to solve problems based on the topic. If you are looking for solutions of NCERT Textbook problems based on this topic, then log on to Vedantu website or download Vedantu Learning App. By doing so, you will be able to access free PDFs of NCERT Solutions as well as Revision notes, Mock Tests and much more.

FAQ (Frequently Asked Questions)

What is BHC?

BHC is the abbreviation of benzene hexachloride. Benzene hexachloride (BHC) is an organochlorine chemical compound which is an isomer of gammaxene with the formula C6H6Cl6.

What is Benzene Hexachloride Used for?

Benzene hexachloride is mainly used in agricultural and pharmaceutical fields. It is used for treatment of lice and scabies.

Why is Benzene Hexachloride Dangerous?

Benzene hexachloride is dangerous as it is a persistent organic pollutant and may cause various harmful effects to our environment and ecosystem. Other than that, over exposure of benzene hexachloride  may cause cancer in humans. India’s BIS considers BHC a ‘confirmed carcinogen’.