Peroxyacyl Nitrates (PANs)

Definition

Peroxyacyl nitrates (PANs) are a group of secondary pollutants formed by chemical reactions between volatile organic compounds (VOCs) and nitrogen oxides (NOx). They contribute to photochemical smog formation and can cause eye irritation and respiratory problems.

Related terms

Photochemical Smog: PANs are key components in the formation of photochemical smog. This type of smog occurs when sunlight reacts with primary pollutants like nitrogen oxides and volatile organic compounds, resulting in a mixture of harmful secondary pollutants.

Eye Irritation: Exposure to high levels of PANs can cause eye irritation symptoms such as redness, itching, tearing, or a burning sensation. These effects are similar to what happens when you accidentally get soap or shampoo in your eyes.

Secondary Pollutants:

Unlike primary pollutants directly emitted into the atmosphere, secondary pollutants like PANs are formed through chemical reactions involving primary pollutants. They often have more adverse effects on human health than their precursor substances.