The intensity of use hypothesis is widely used both as an explanation of trends in materials consumption over time and as a predictive tool. The paper examines significant weaknesses in the data normally used to test the hypothesis. An examination of long-term trends in the intensity of apparent first use of aluminium, copper and steel in eight countries shows a tendency for usage per unit of GDP to follow an inverted U shape as per capita GDP increases. Cross country comparisons for individual years do not demonstrate such a relationship. Apparent first uses are not always good guides to actual consumption, and the weaknesses in the data are discussed. Per capita GDP is only one influence on materials usage, and the paper looks at other factors, and most notably at the structure of both output and expenditure. China’s intensity of use appears anomalous, raising questions about future trends in its materials usage. Avenues for future research are outlined.