Pollutants in food processing mainly can be classified into two kinds: dust from handling dry bulk materials or wet discharges such as grease or smoke from cooking.
Dry dusts vary from thick to fine particles. Pollutants are generated at the product transporting or loading with displacement volumes containing dust airborne, such as at bagging or dumping sites. The size, process, velocity and material characteristics will affect the dust properties and generation rate. In some conditions, the created dust may be agglomerated, hygroscopic, flammable or explosive.
Cooking emissions can be grease created in frying processing, or smoke from burning or baking solid fuels, or both. Due to the existing heat and organic compounds, the chemical property of contaminants may be more complicated. Grease are generally of a larger size (> 1µm) and consists of processing materials such as the oil and ingredients being cooked. Grease can also be a fire hazard when collected.
Smog pollutants are submicroelectronics (< 1µm1m) and could consists of solid fuels, process ingredients or other pollutants. Using solid fuels such as wood to cook may also include creosote to be a pollutant. The odour released in of gas form during cooking may also be a concern for the facilities and environments.