The Basics of Fire

Humans have used fire for thousands of years to create heat and light, to cook food, to clear land, for signaling, propulsion, smelting, and incineration of waste. We have also used fire as a weapon. Read on to learn about the history of fire. Read on to learn about the many ways that fire has been used and the products of combustion. Now that you know the basics of fire, you can use it to better understand your own personal safety and that of others.


The flame that erupts from a fire is a mixture of gases and heat. This mixture produces visible, infrared, and ultraviolet light. The wavelength of the flame depends on the chemical composition of the burning substance. The flame from a solid is reddish or orange, due to the presence of incandescent particles. A gas flame produces single wavelength radiation due to electron transitions in excited molecules. For instance, hydrogen burning into chlorine produces hydrogen chloride.


The basic ingredients for combustion are fuel, oxygen and heat. During combustion, these elements combine to form the fire tetrahedron. This process also produces heat and exhausts. The fuel, the oxygen, and the source of heat control the speed of the combustion process. During combustion, the fuel’s temperature rises as it undergoes different reactions. However, the temperature rises very slowly if the fuel is not heated to hundreds of degrees Celsius.


Oxygen and fire are important components of the carbon cycle. They help keep our environment healthy and can also contribute to our understanding of the history of life on earth. In fact, scientists have dated the first fires back 400 million years, which is when oxygen levels in the atmosphere were much lower. Today, atmospheric oxygen levels are much higher, with a corresponding increase in the likelihood of fuel burning. Nevertheless, understanding the relationship between oxygen and fire is essential in determining our history of life on Earth.

Combustion products

Fires produce a mixture of toxic combustion products known as “combustion gases” that contain a variety of hazardous chemicals. These substances include carbon monoxide (CO) and hydrogen cyanide, which are toxic compounds derived from the breakdown of fuels. These products can be harmful to the human respiratory system, and are known to cause a wide range of other health effects. Asphyxiant gases can even cause death. Irritants, on the other hand, can cause respiratory illness and impair escape.

Flame size

When calculating fire intensity, flame size is an important consideration. The flame’s length is the distance between the center of the flaming zone and the average flame tip. The flame’s length also indicates the rate at which the flame front advances. As the flame length increases, suppression efforts become increasingly difficult. This article will explore the different methods for estimating the flame length. Here are a few examples of the methods for calculating fire intensity.

Flame color

Fires are often characterized by different flame colors. These colors are a function of the types of substances burning within them. Hotter fires have more energy, and their colors change accordingly. For instance, a green flame indicates the presence of copper, while a pink flame means that the substance being burned is lithium chloride. A red flame is the result of burning strontium chloride. Burning chemicals can be toxic, and scientists create flames in a controlled environment to avoid any negative health effects.

Flame spread

Flame spread is a critical property when evaluating a building material for its fire safety. It describes the way the materials burn and the amount of smoke they produce. Flame spread is one of the most commonly tested fire performance properties. The American Society for Testing and Materials (ASTM) developed the E-84 test method to determine the spread of flame of a variety of building materials. In addition to the tunnel test, many small-scale tests have been developed to predict flame spread ratings.