One of the main problems of fire-resistant technology for fills openings in fire barriers is providing of the required level of integrity between the contour of the opening and inserted into the opening fireproof construction (fire-door or fire-hatch frame, duct fire damper, etc.) is considered. Features of ensuring for fireproof constructions having only minor cracks or holes in its contours in width from 1 to 10 mm with using of special flame retardant foams and fire sealants to prevent the combustion products having high ignition capacity to penetrate from one room to another and cause a fire spreading in the building are appended. The necessity to take into account during fire tests a properties of mounting fire-foams are used for fire resistant sealing space between the bundle of cables, passing through the open doorway of fire barriers, especially depend on chemical properties of materials, and also the thickness and depth filling of openings, is substantiated. The designing of fire-resistant clearance leakage sealings between the bundle of cable products passing through the technological opening in a fire barrier that represents a special structure, called penetration seal, that should not only seal the all the free passages between the sheath of the cable, but also to maintain its integrity in the process of fire exposure, providing the required fire resistance for loss of insulating capacity (I), a loss of integrity (E) and the critical temperature of cabel sheaths heating (T), is examined.