peroxyacetyl nitrateper·ox·y·a·cet·yl nitrate
an unstable nitrogen compound, found in certain types of smog, that is an irritant, esp. to the eyes and to plants
Origin of peroxyacetyl nitrateper- + oxy- + acetyl
Abbr. PAN A toxic organic compound, C2H3NO5, formed photochemically in smog, causing eye irritation and damage to vegetation. Due to the stability of this compound, it may be transported in air over long distances before breaking down into smaller reactive compounds.