Bleeding Injection - EX

Weapons you wield that have the injection weapon special property gain bleed 1d4 as a critical hit effect. If the weapon already has the injection critical hit effect, you can apply both effects when you score a critical hit. If the weapon has another critical hit effect, apply either the weapon’s normal critical hit effect or this bleed effect. The bleed damage increases to 2d4 at 11th level, 3d4 at 15th level, and 4d4 at 19th level.