Poisoned (X) "A Weapon with the Poisoned (X) Special Rule has a chance to cause a wound regardless of the target's Toughness Characteristic."
When making Wound Tests for Hits that have the Poisoned (X) Special Rule, if the result of any Dice rolled is equal to or greater than the value of X attached to the specific variant of this Special Rule then a wound is caused automatically, regardless of the Toughness Characteristic used to determine the Target Number. A Hit that has this Special Rule may still inflict a wound by passing a Wound Test as normal, instead of using this Special Rule, but never inflicts more than 1 wound if it would both pass the Wound Test and trigger the Poisoned (X) Special Rule. Wounds caused using the Poisoned (X) Special Rule retain the AP and Damage Characteristics of the Weapon and Saving Throws and Damage Mitigation Tests may be made to discard them as normal. The Poisoned (X) Special Rule has no effect on Models that have the Vehicle Type, and limited effect on Models with the Automata or Walker Types (See the Rules for Walkers and Automata in the Warhammer: The Horus Heresy - Age of Darkness Rulebook).