A gassing insulator for the arc chute assembly of a circuit breaker includes a number of insulating members. The arc chute assembly includes first and second opposing sidewalls, and arc plates having first and second ends and first and second legs. Each insulating member includes a first side coupled to one of the first and second opposing sidewalls of the arc chute assembly, a second side disposed generally opposite the first side, a first end disposed at or about the first ends of the arc plates, and a second end disposed distal from the first end of the insulating member and extending toward the second ends of the arc plates. The first side of the insulating member overlays at least one of the first and second legs of the arc plates, in order to electrically insulate them. An arc chute assembly and an electrical switching apparatus are also disclosed.