In most countries, farmers and other animal establishments are also legally obliged according to local pollution and/or agricultural health laws, to account for the circumstances of any livestock or animal death and their subsequent proper disposal—hence the use of a licensed knackery. This includes the proper disposal of stillborn animals, and the afterbirth from either live-born or stillborn. This ensures they do not enter the food chain for human consumption through unscrupulous practices or cause environmental pollution or contamination (biological hazard).