Risk assessment for fat derivatives in case of contamination with BSE

Prion diseases are not only of outstanding scientific interest but have also enormous economic impact. In particular, the human food and animal feed industry and even oleochemical manufacturing processes are afflicted. In the oleochemical industry, bovine edible tallow is widely used as raw material for the production of fatty acids, glycerol, and their derivatives. Although there is no evidence that tallow has been a causal factor for BSE nor that infectivity partitions preferentially with tallow, the potential risk associated with tallow-derived products has to be evaluated in the light of the specific production process. To the present day, no experimental data under technically relevant conditions are available on the safety of fatty acids, glycerol, and their derivatives in the case of a hypothetical contamination of tallow with prions. A risk assessment calculation is provided here based on quantitative data for the degradation of the pathological prion protein as well as the inactivation of prion infectivity. It can be concluded that the industrial conditions of the basic oleochemical process of hydrolytic fat splitting constitute an effective means for reducing the risk of TSE contamination to an acceptable minimum. All industrial tallow-derived products can be regarded as safe, independently of their origin.