The amount of leachable glutaraldehyde from medical grade Cuprophan 150PM (cellulose based) and AN69S (a copolymer of acrylonitrile and sodium methallyl sulphonate) membranes, and polyproprene plates following 72 hr immersion in 2% alkaline glutaraldehyde was determined. After rinsing the materials for 30 minutes in distilled water at 37 degrees C, the mean concentration of leachable glutaraldehyde from Cuprophan 150 PM (8. 60 +/- 0.55 micrograms/g) was significantly greater than that from AN69S membrane (6.50 +/- 0.60 micrograms/g), (p < 0.01). The mean leachable glutaraldehyde from plates was 0.30 +/- 0.15 microgram/g. There was a significant decrease in the mean leachable glutaraldehyde from AN69S (5.35 +/- 0.25 micrograms/g) after second immersion (p < 0.05). The concentration of leachable glutaraldehyde in the plates and Cuprophan 150PM remained relatively unchanged. Absence of growth following infusion of 2% alkaline glutaraldehyde into blood contaminated miniature dialyzers containing high microbial loads of selected bioindicator organisms (S. aureus, P. aeruginosa, B. subtilis (Var globigii) spores, M. gordonae, A. niger spores and attenuated polio virus) demonstrated its effectiveness under environmental conditions that were conducive to high resistance. These findings indicate that 2% alkaline glutaraldehyde is readily washed from the three polymer materials that were studied and its accumulation following repeated exposure was not evident. Its application in pre-sterilization treatment of heavily contaminated invasive polymer based devices seemed feasible.