Colors of Smoke and Flame (2024)

FAQs

Colors of Smoke and Flame? ›

Whether a flame is light yellow, orange-yellow, or reddish depends on the temperature of the flame. The hotter the flame, the lighter the color. White or light gray smoke is usually associated with paper, straw, leaves, or wood.

However, smoke color can enlighten the firefighter as to what stage of burning is taking place or where the fire is burning within the building. Virtually all solid materials emit white smoke when first heated, this is moisture being released. As the materials start to dry out the smoke changes colors.

Class “A” fire: (leaves an ash) White smoke. Class “B” fire: (stored in barrels) - Black smoke. Burnable liquids and solid hydrocarbons such as paraffin, plastic, fuel oils, etc. Class “C” fire: Electrical fires.

The colder part of a diffusion (incomplete combustion) flame will be red, transitioning to orange, yellow, and white as the temperature increases as evidenced by changes in the black-body radiation spectrum. For a given flame's region, the closer to white on this scale, the hotter that section of the flame is.

Blue flames are the hottest, followed by white. After that, yellow, orange and red are the common colours you'll see in most fires. It's interesting to note that, despite the common use of blue as a cold colour, and red as a hot colour – as they are on taps, for instance – it's the opposite for fire.

Under these conditions, the smoke can ignite and create a hazardous and possibly deadly situation for firefighters. When a fire produces dark brown or even black it is an indication that the fire is underventilated and/or it contains an abundance of petroleum products.

White smoke can often mean material is off-gassing moisture and water vapor, meaning the fire is just starting to consume material. White smoke can also indicate light and flashy fuels such as grass or twigs. Thick, black smoke indicates heavy fuels that are not being fully consumed.

White or light gray smoke is usually associated with paper, straw, leaves, or wood. It is formed of pyrolysis products (gasses, liquids, and tars) that condense to form a fog of tiny droplets that bypass the flame.

Anyway, achieving blue smoke means your coals are red hot. At this stage, the majority of your coals are likely burning thoroughly and more evenly, whereas white smoke is generated by having just the outside of your coals on fire which makes for uneven heat.

A red glow is produced when temperatures are about 932°F. Red flames occur at 1112-1832°F and turn orange between 1832-2192°F. At 2192-2552°F the flames turn yellow and if they get hotter the flames become blue-violet. Orange is the most common color for flames.

What is the most powerful flame color? ›

Blue fire can reach temperatures upwards of 2,552 to 2,912 degrees Fahrenheit (1,400 to 1,600 degrees Celsius), showcasing its superiority in the hierarchy of flame heat.

The hottest fire color is violet. This is because when a fire reaches temperatures between 1300-1500 degrees Celsius (2400-2700 degrees Fahrenheit), the light emitted from the flame becomes so intense that it begins to occupy the entire visible spectrum of colors.

When a flame burns cleanly like a gas flame, blow torch, or the base of a candle, the heat excites the molecules to release light, usually pale blue, from atomic transitions. That's from quantum mechanics.

White smoke usually means coolant is getting into the combustion chambers of your vehicle. This generally happens because of a cracked or leaking head gasket, which allows coolant to seep into your cylinders.

Heavy white smoke – This is what many beginners mistake for "Look at all that good smoke!". The particles are smaller, but they still have creosote, impure carbon, and soot that will give your food that harsh, over-smoked flavor.

The molecules of smoke are bigger than the wavelength of light, so they scatter lights of all colours equally and the scattered light appears white.

When temperatures approach 2,400º F to 2,700º F, flames appear white. You can see these differences for yourself by observing a candle flame or a piece of burning wood. The part of the flame closest to the candle or the wood will usually be white, since the temperature is usually greatest near the fuel source.