Hydrogen chloride primary pollutant

Besides ozone, the main indicator of photochemical pollution, other important concomitant products are peroxyacetylnitrate (PAN), hydrogen peroxide, nitrogen dioxide, hydroxyl radicals and various aldehydes that are both products and primary pollutants, particles, sulfates, nitrates, ammonium, chloride, water, and various types of oxygenated organic compounds. The most important precursors of photochemical pollution are nitric oxide and hydrocarbons. The measurement procedures for the hydrocarbons are not as highly developed as those for ozone and the nitrogen oxides. 

The incineration of liquid and solid wastes produces gases with a variety of potential corrosives present. Usually they are some combination of nitrogen, phosphorus and sulfur oxides and some hydrogen fluoride, but the primary contaminant is almost always hydrogen chloride. The exact composition oftentimes is variable and unpredictable in any one incinerator. Before incineration gases can be vented, they must be scrubbed of these noxious pollutants. 

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