Abstract: Improvements in retention of the oily liquid sealant (20) in a oil-sealed odor trap (10B-10M), for drain applications such as a waterless urinal or anti-evaporation floor drain, are accomplished by minimizing turbulence in the oil sealant, such as by making the liquid flow path (22A, 22B) substantially horizontal as a departure from conventional practice of substantially vertical flow and by positioning a barrier (40) above the oil sealant to prevent direct impingement of urine or other waste products onto the sealant. The trap is thus structured to realize the substantially horizontal liquid flow path and to locate the flow path immediately beneath the sealant layer or beneath a baffle portion (16B). The baffle portion may be sloped such that stray sealant droplets are encouraged to migrate upwardly to the upper surface of the flow path due to their buoyancy and, therefore, the stray droplets will be recaptured and returned to the main sealant layer.