An interface assembly (1012) comprises a mask body (1022,1024, 2022, 2086) coupled to a seal member (1020), the mask body comprising an outer forwardly facing surface (1064) and an inner rearwardly facing surface , a passage (2085) extending through the mask body, an antiasphyxiation valve (1084, 2084) positioned within the passage, the antiasphyxiation valve being sandwiched between at least one inner member (1022, 2086) and at least one outer member (1024, .2087)
