[en] A filtered pressure equalization system (FPES) for a waste transportation package has been designed and qualified to withstand the package environments induced by the normal and accident condition requirements specified in 10 CFR 71. The use of an FPES reduces the package structural requirements to withstand pressure variations due to gas generation from the payload and elevation changes, and permits the design of a more weight efficient package. The filter is capable of trapping airborne particles, should any be released from the contents to the containment vessel. Particle containment is important for flow from inside the package to outside. 1 ref., 5 figs