A cold trap is a condensing device to prevent moisture contamination in a vacuum line.

Guidelines for using a cold trap include:

• Locate the cold trap between the system and vacuum pump.
• Ensure that the cold trap is of sufficient size and cold enough to condense vapors present in the system.
• Check frequently for blockages in the cold trap.
• Use isopropanol/dry ice or ethanol/dry ice instead of acetone/dry ice to create a cold trap. Isopropanol and ethanol are cheaper, less toxic, and less prone to foam.
• Do not use dry ice or liquefied gas refrigerant bath as a closed system. These can create uncontrolled and dangerously high pressures.

21. Disinfectant Trap

A disinfectant trap should be used in-line when a vacuum is used with hazardous biological materials.