Abstract Following a request from European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the safety for the environment of the proposed modification of the terms of the authorisation regarding the formulation of the additive Lactococcus lactis NCIMB 30160. The applicant has proposed to modify the manufacturing process by adding polyethylene glycol (PEG 4000) in the list of potential cryoprotectants that can be used in the freeze‐drying step, up to a maximum concentration of 0.025 mg PEG 4000/kg silage. The use of PEG 4000 as an excipient in formulations with Lactococcus lactis NCIMB 30160 would not change the previous conclusions regarding the safety for the target animals, consumers and users. No safety concerns are expected for the environment when PEG 4000 is used as a cryoprotectant in the additive Lactococcus lactis NCIMB 30160 up to a maximum concentration of 0.025 mg PEG 4000/kg silage.