We had previously established that high eBeam doses were necessary for meaningful PFAS degradation in environmental matries. Upon exposure to 2000 kGy, the PFOS concentrations in composted biosolid samples decreased from 59.3 ng/g in untreated samples to 2.01 ng/g in eBeam treated samples, showcasing a 94% total PFOS degradation. In non-composted biosolid samples, PFOS concentration decreased from 20.5 ng/g to 0.98 ng/g (93.6% reduction), and PFOA concentration in residual solids fell below analytical detection limits. In such high dose treatments sample temperatures as high as 400°C can be encountered. Was PFAS destruction only due to the eBeam dose or temperature or both? Therefore, we devised experiments to investigate the impact of temperature increase during a 2000 kGy treatment on PFAS degradation. We focused on incremental low eBeam doses (25 kGy) applied to PFAS-impacted biosolid samples and non-composted biosolid samples until reaching a total of 2000 kGy. The results were striking. A distinct difference emerged in the results obtained when the biosolid samples were directly exposed to 2000 kGy compared to sludge samples exposed to 2000 kGy incrementally (without concurrent temperature effects). In the composted biosolid samples, the reduction of PFOS was 14% at 500 kGy, 25% at 1000 kGy, and 47% at 2000 kGy, in contrast to the 97% reduction observed when the same biosolid samples were directly exposed to 2000 kGy. Thus, approximately 50% of the observed PFOS reduction at high eBeam doses can be attributed to temperature effects, while the remaining 50% can be attributed to the involvement of ionization chemistry and a synergy between ionization chemistry and temperature.