contamination

This term is defined in ECSS-Q-ST-70-08C as
particles, liquids, gases, materials and micro-organisms which by their presence can disturb the performance of an item

This term is defined in ECSS-S-ST-00-01C as
introduction of contaminant to an item or to the environment of interest

This term is defined in ECSS-Q-ST-70-60C as
” foreign material embedded in dielectric material