Asbestos

A white, powdery rock explodes against a creature within 30 feet of you that you can see, sending it into a horrible coughing fit. That creature must make a Constitution saving throw or take 9 (2d8) poison damage and becomes Prone, or half as much damage and doesn't become prone on a success. Damage increases by 1d8 for each level above the 1st. When cast at the 4th level or higher, the target creature also becomes Poisoned on a failed save. When cast at 8th level or higher, the target creature has disadvantage on Constitution saving throws for 1 minute.