Trans-Fatty Acids (frying & roasting aerosols) — properties & hazards overview
Physical state
Condensed oil mist / aerosol
Melting point
≈ 45 °C (elaidic acid)
Volatility
Low — thermally entrained, then condenses
Water solubility
Practically insoluble
Toxicity
Low acute toxicity
Flammability
Combustible deposits
Chronic risk
Cardiovascular (dietary route)
Environmental
FOG load; fouling; odour
| Property | Value / Note |
|---|---|
| Scope | Unsaturated fatty acids in the trans configuration, formed by partial hydrogenation and by prolonged heating of frying oil. Elaidic acid (C18:1 trans-9) is the reference compound. |
| Physical behaviour | Leaves the process as vapour and fine mist at process temperature, then condenses on the first cool surface — usually the duct wall or the demister. |
| Accompanying emission | Rarely alone: aldehydes, acrolein, free fatty acids and PM travel with them, and those set the odour and irritation. |
| Health context | The recognised health effect (cardiovascular) is dietary, not occupational; the occupational concern is oil-mist exposure and irritation. |
| Typical sources | Peanut and nut roasting, crisp and snack frying, oil refining and deodorising, rendering and fat melting. |
| Best analytical detection | Isokinetic gravimetric sampling for total oil mist, FID for the accompanying volatile organics, and GC-FID after methylation (FAME) where the trans fraction itself must be quantified. |
*Indicative values; verify via SDS and process data. Oil-mist emissions are usually regulated as total organic carbon or as PM, not as trans-fatty acids specifically.