Proteins (aerosols & dust) — properties & hazards overview
Volatility
Non-volatile (particulate / aerosol)
Water affinity
Soluble or colloidal; foams readily
Degradation products
NH₃, amines, H₂S, mercaptans
Environmental
Very high COD / BOD and nitrogen
Toxicity
Low acute toxicity
Flammability
Combustible dust when dry
Chronic risk
Respiratory sensitiser
Environmental
COD / N load; odour
| Property | Value / Note |
|---|---|
| Composition | Polymers of amino acids; in off-gas as fine dust from drying and milling, or as droplets from cooking, evaporating and spray-drying. See also the sheets Amino Acids and Enzymes. |
| Physical state | Solid particulate when dried; liquid aerosol when carried from a wet stage. |
| Reactivity | Denature and coagulate with heat and pH shift — useful for recovery, but they also foul heat exchangers and packing. |
| Behaviour in a scrubber | Captured by impaction and dissolution. They foam persistently in the sump and feed rapid biological growth if the liquor is warm. |
| Typical sources | Potato and vegetable processing, dairy and egg drying, offal and blood processing, fermentation and enzyme production. |
| Best analytical detection | Isokinetic gravimetric PM sampling for the emitted mass; total nitrogen (Kjeldahl) and COD in the liquor to quantify the captured load; olfactometry where decomposition odour is the complaint. |
*Indicative values; verify specifics via SDS/process data. Enzyme-containing dusts are treated as respiratory sensitisers even at very low concentration.