People confuse baking powder and baking soda constantly, which is harmless in a recipe and matters a lot when a pan is on fire. Both are white powders in the baking aisle. Only one of them is worth grabbing in an emergency.
Baking powder is not flammable. It will not ignite or burn. But unlike baking soda, baking powder is a poor fire extinguisher: it contains cornstarch, which is itself combustible as a fine dust, and it produces far less carbon dioxide when heated. If you have a small grease fire, use a lid, salt, or baking soda. Not baking powder.
What's Actually in Baking Powder
Baking powder is a mix of three things: baking soda (sodium bicarbonate), a dry acid such as cream of tartar or sodium aluminum sulfate, and a starch, usually cornstarch, to keep it dry. The acid and base react when wet to make the bubbles that leaven a cake. None of those ingredients is flammable in the can. The cornstarch is the catch.
Why It's a Bad Fire Extinguisher
Baking soda works on a grease fire because heat breaks it down into carbon dioxide, which smothers the flame, and because a heavy layer of powder blocks oxygen. Baking powder is only about a quarter to a third baking soda by weight, so it releases much less CO2. The rest is starch and acid salts that just sit there. Worse, cornstarch is a fine organic powder. Thrown into the air over a flame, starch dust can flash, the same way flour can. It is not likely to cause an explosion from a spoonful, but it can make the fire briefly bigger instead of smaller. See can flour put out a fire for why powdery kitchen ingredients are a bad idea.
What to Use Instead
- A lid or baking sheet. Slide it over the pan and turn off the burner. This is the best answer almost every time.
- Baking soda, a lot of it, dumped on a small fire.
- Salt, same approach.
- A Class B, K, or ABC fire extinguisher.
- Never water on a grease fire, and never carry a burning pan.
Is Baking Powder Dangerous Around Heat?
No. A can of baking powder in a cabinet next to the stove is fine. The only way to get it to do anything alarming is to blow a cloud of it through a flame. Store it dry, use it for pancakes, and keep the baking soda on the shelf for emergencies.
Related reading: is baking soda flammable, can baking soda put out a fire, and is cornstarch flammable.
