What is the fastest acting poison?

-Cyanide Salts(1-15 minutes) -Aspirin
-Nicotine(very fast in high doses, only about 30 seconds and they will be the best seconds of your life)
-Tylenol
-Oleander
-Ricin(not fast but very deadly)
-Foxglove
-Monkshood
-Chlorine(takes less than a minute but VERY painful)