What are PAHs classified as?

Polynuclear aromatic hydrocarbons (PAHs) are a class of organic compounds consisting of multiple fused aromatic rings. The term "polynuclear" refers to the presence of multiple aromatic nuclei, meaning that these compounds are formed from the fusion of multiple benzene rings. PAHs are known for their environmental persistence and potential health risks, particularly as carcinogens.

The classification of PAHs is critical in environmental science and health studies, as they are commonly found as pollutants in various environments, especially in soil and air, due to incompletely burned organic materials. Understanding what PAHs are and their chemical structure helps in environmental monitoring and risk assessment.

The definition provided in the correct choice accurately captures the chemical nature of PAHs, emphasizing their structure and significance in environmental health discussions.