A process for treating plastic waste chips containing a blend of polypropylene and polyethylene in an amount of at least 83.0 wt.-% to less than 100 wt.-% and further containing C7 to C11 aldehydes and limonene, the process comprising the steps of: (a) providing plastic waste chips in a treatment vessel having inlet and outlet for gas at opposite sides at upper and lower part section of the treatment vessel, whereby the plastic waste chips contain - C7 to C11 aldehydes in an amount of 8000 ppb to 20000 ppb as determined by using HS-SPME-GC x GC-MS; and further contain - limonene in an amount of 5 ppm to 500 ppm as determined by using HS-SPME-GC-MS (b) optionally washing and drying said plastic waste chips of step (a); (c) optionally preheating said plastic waste chips to a temperature in the range of 20°C to a point 10°C below the Vicat softening point (10N, ISO 306) of said plastic waste chips; (d) subjecting said plastic waste chips, in a fixed bed without stirring under standard pressure or reduced pressure, to a gas flow for achieving a Reynolds number in the range of 35 to 1200 at a temperature in the range of 20°C to a point 10°C below the Vicat softening point (10N, ISO 306) of said plastic waste chips; (e) recovering the treated plastic waste chips containing · C7 to C11 aldehydes in a total amount of 50 ppb to less than 5000 ppb as determined by using HS-SPME-GC x GC-MS and · limonene in an amount of 0.5 to 5 ppm as determined by using HS-SPME-GC-MS; (f) subjecting said treated plastic waste chips of step (e) to an extrusion step yielding pellets; (g) recovering said pellets. (a) providing plastic waste chips in a treatment vessel having inlet and outlet for gas at opposite sides at upper and lower part section of the treatment vessel, whereby the plastic waste chips contain - C7 to C11 aldehydes in an amount of 8000 ppb to 20000 ppb as determined by using HS-SPME-GC x GC-MS; and further contain - limonene in an amount of 5 ppm to 500 ppm as determined by using HS-SPME-GC-MS - C7 to C11 aldehydes in an amount of 8000 ppb to 20000 ppb as determined by using HS-SPME-GC x GC-MS; and further contain - limonene in an amount of 5 ppm to 500 ppm as determined by using HS-SPME-GC-MS (b) optionally washing and drying said plastic waste chips of step (a); (c) optionally preheating said plastic waste chips to a temperature in the range of 20°C to a point 10°C below the Vicat softening point (10N, ISO 306) of said plastic waste chips; (d) subjecting said plastic waste chips, in a fixed bed without stirring under standard pressure or reduced pressure, to a gas flow for achieving a Reynolds number in the range of 35 to 1200 at a temperature in the range of 20°C to a point 10°C below the Vicat softening point (10N, ISO 306) of said plastic waste chips; (e) recovering the treated plastic waste chips containing · C7 to C11 aldehydes in a total amount of 50 ppb to less than 5000 ppb as determined by using HS-SPME-GC x GC-MS and · limonene in an amount of 0.5 to 5 ppm as determined by using HS-SPME-GC-MS; · C7 to C11 aldehydes in a total amount of 50 ppb to less than 5000 ppb as determined by using HS-SPME-GC x GC-MS and · limonene in an amount of 0.5 to 5 ppm as determined by using HS-SPME-GC-MS; (f) subjecting said treated plastic waste chips of step (e) to an extrusion step yielding pellets; (g) recovering said pellets.