AGI-30 impingers and the PGP dust-sampling system were used to collect airborne endotoxin in animal houses. Both sampling methods correlated well with each other (r(2) = 0.75). The collection efficiency of the impinger was higher than the efficiency of the PGP dust-sampling system, especially in animal houses with high concentrations of airborne endotoxin. The use of AGI-30 impingers for sampling airborne endotoxin is limited to short-term investigations, due to continuous loss of sampling fluid during operation. AGI-30 impingers offers the possibility for simultaneous measurement of airborne bacteria and endotoxin. (C) 2000 Elsevier Science Ltd. All rights reserved.