Coal tar is a mixture of about 200 substances, used as starting materials for various industrial products.

Understanding Coal Tar
Coal tar is a thick, black liquid that is a by-product of the carbonization of coal. It is composed of a complex mixture of organic compounds, primarily aromatic hydrocarbons, phenols, and heterocyclic compounds.
Composition of Coal Tar
- Coal tar contains approximately 200 different substances.
- These substances include:
- Polycyclic Aromatic Hydrocarbons (PAHs): A major component, contributing to its properties and potential health risks.
- Phenols: These compounds have antiseptic properties and are used in various applications.
- Heterocyclic Compounds: These include nitrogen-containing compounds that can affect the tar's behavior and applications.
Uses of Coal Tar
- Pavement Sealants: Coal tar is often used in sealants for asphalt pavements due to its waterproofing and protective properties.
- Medicinal Products: It is used in dermatological products for treating skin conditions like psoriasis and eczema.
- Manufacturing: Coal tar serves as a raw material for producing chemicals like dyes, drugs, and plastics.
Environmental and Health Concerns
- Due to the presence of PAHs, coal tar can pose environmental risks. Proper handling and regulation are essential to mitigate potential health hazards.
In summary, coal tar is a complex mixture containing around 200 substances, making it a significant material in various industrial and medicinal applications. Understanding its composition and uses is crucial for its safe handling and application.