Single aliquot infra-red stimulated luminescence measurements have been carried out on feldspar from sands from a range of aeolian, colluvial and alluvial environments in an attempt to determine their degree of bleaching at burial. Two coupled parameters have been devised to indicate degree of bleaching and to discriminate samples which would be a problem in IRSL dating. These are used to show that aeolian, as well as colluvial and alluvial sands, can show poorly bleached behaviour.