You can die while tampering with your inventory as soon as chapter 2 by combining Gasoline with a Cigarette Butt, but you won't unlock the achievement via that method.
This achievement can be unlocked in the same place you find this medal (collateral damage) in chapter 3. A room with chemical elements such as Sodium, Water, Chloro, Form....
By combining Sodium with Water, you create an explosion that instantly kills you and the achievement will be unlocked. Be sure to save your game beforehand.