Efferocytosis, that is, the removal of dead cells by macrophages, is a key process in the growth, regression and resolution of atherosclerotic plaque. Macrophages acquire internalised lipid when they ingest dying cells. Using data from an in vitro experiment measuring macrophage population and average ingested lipid per cell, we explore the processes of efferocytosis and apoptosis in this population. We find that the death rate of macrophages increases with time, which, we suggest is effectively due to their age—at the start of the experiment all cells are the same age. We also find that the rate of efferocytosis is not depndent on the average macrophage lipid load. This agrees with the hypothesis that defective efferocytosis may be a driver of atherosclerosis.