Dust of Sneezing and Choking
This fine dust appears to be Dust of Appearance. If cast into the air, it causes those within a 20-foot spread to fall into fits of sneezing and coughing. Those failing a DC 15 Fortitude save take 2d6 points of Constitution damage immediately. In addition, those failing a second DC 15 Fortitude save 1 minute later are dealt 1d6 points of Constitution damage. Those who succeed on either saving throw are nonetheless disabled by choking (treat as stunned) for 5d4 rounds.
Creation
Prerequisites
Feats: Craft Wondrous Item
Spells: Poison