The surface photovoltage (SPV) method is used to characterize metallic contamination introduced by wafer handling. It is shown that particles from handling equipment introduce significant levels of metallic contamination. In most cases the correlation between particle contamination and metallic contamination is excellent. We also find that metallic contamination can be introduced during handling in areas where no particles are detected. However, in order to take manufacturing decisions based on surface photovoltage data, one must understand the strengths and limitations of the technique and avoid its pitfalls.