Scientific Opinion on Lime Treatment of Solid Pig and Poultry Manure

EFSA’s Scientific Panel on Biological Hazards (BIOHAZ) was asked for a scientific opinion on a novel process submitted by a European association as a safe means of disposal of Animal By-Products (ABP) according to Regulation (EC) 1774/2002 . The application received describes a lime treatment process for dewatered pig and solid poultry manure which could be operated at two different temperatures (60°C and 70°C). The applicant carried out full scale trials for a batch process (i.e. stockpiles) utilizing quick lime (CaO) and demonstrated that the proposed process inactivated the relevant bacterial pathogens (Salmonella) and indicator (Enterococcus faecalis) by more than 5 log10 and the relevant virus and parasite eggs by more than 3 log10. The Panel concluded that the information provided by the applicant is sufficient to show that the mixing of dewatered pig and solid poultry manure with quicklime at the requested exposure time of 30 or 60 minutes, respectively for treatment at 70°C and 60°C at pH 12 meets the requirements for Agent Risk Reduction. However, it was highlighted that the assessment provided cannot be extended to different equipments, different types of manure and different incubation conditions than those used in the experimental validation. Moreover, the applicant did not give sufficient information to ascertain that in practice the target temperatures and pH are achieved in all part of the stockpile for the sufficient time period. The BIOHAZ Panel recommended that the proposed processes can be considered able to safely process dewatered pig and solid poultry manure only if certain given conditions are met.