All WHIFFS® masks are made from Nomex® IIIA cloth. The mask's breathing port is made from Nomex knitted material. The attachable neck shroud for the WHIFFS mask and the WHIFFS Bush Pro® mask is also made of Nomex IIIA cloth. The thread used in the construction of all masks is Nomex craq spun thread. All cloth-lined Whiffs masks meet the Radiant Protective Performance Standard described in the NFPA's 1977 Standard on Protective Clothing and Equipment for Wildland Firefighting. The MopPro® mask does not meet this standard and is designed for use in non-heat situations. (Nomex is a registered trademark of Dupont Industries)

The Xcaper® filter contains a revolutionary, state of the art, moist filtering agent (gel) that traps most water soluble (anhydrite) gases and smoke particulates common to wildland fires as well as those found in structural overhaul situations. Laboratory tests show that the Xcaper filters particulate matter down to the 1-2 micron level. The moistening agent (gel) is an odorless and tasteless all-natural plant extract, with an increased viscosity for enhanced breathability. An antibacterial agent is added to the gel to ensure each filter's freshness. Field tests by wildland fire fighters show that the filtering agent will not steam in a burn-over situation.

The Xcaper filter cloth has a special weave for easier breathing and is made of 100% polyester that passes the California 117E flammability test (direct flame for 54 seconds with no ignition). A Hydrolon finish promotes wicking. The filter medium that allows each filter to fit every face is an expanded polystyrene bead. The beads will not off-gas or ignite until 810°.

Field-testing and use by over 4,200 firefighters during the 2000 fire season has shown that this state-of-the-art filtration system protects your lungs from most of the hazards found in smoke.