Paraformaldehyde solution (32%) is kept in the fume hood in sealed 10-ml glass ampules. When you break open a new ampule, please transfer the contents to a clean 10-ml scintillation vial, and clearly label and date the vial. If the date on the current vial indicates that it is >2 months old, the contents should be disposed of in the paraformaldehyde waste container (see Hazardous Waste below). New ampules can be ordered from Electron Microscopy Sciences (www.emsdiasum.com/formaldehyde), product # 15714; be sure to order the 10-ml ampules and not the large bottles.