Gases and Their Hazards
1- What is Gas?
Gases, one of the four basic states of matter, are simply substances that have a boiling point of less than 20°C. (We will not go into details of scientific definitions such as the difference of vapor and gas in this article.) Gases have neither a fixed shape like solids nor a fixed volume like liquids. Gases are in constant motion due to the high energy state of their atoms; they collide with each other in a chaotic manner, mix and spread into the environment. The origin of the word “gas” comes from the Ancient Greek word “chaos”.
2- Importance of Gases for Living Beings
Gases are critical substances for the continuation of life. While human beings survive by breathing oxygen gas like many other living beings, plants and some single-celled organisms need carbon dioxide gas to produce nutrient. Apart from the continuation of life, we use gases in many areas of the industry or we produce various gases as waste. For example, heating, cooling, energy generation is possible with gases.
3- What are the Hazards Caused by Gases?
Our atmosphere, which is the gaseous layer that surrounds the Earth, consists of approximately 78% nitrogen, 21% oxygen, and the remaining 1% other gases such as argon and carbon dioxide. Apart from the gases naturally found in the atmosphere, we are exposed to different gases in daily life due to reasons such as industrial activities and natural events. The human body is specialized to breathe a mixture of atmospheric air, which is about one-fifth of oxygen. Apart from this air mixture, which is indispensable for life, we can say that all other gases have negative effects on human health. It is possible to divide the hazards posed by gases into 3 main topics.
a- Asphyxiant Gases
Even if it does not have any toxic effect, other gases mixed with the breathing air can reduce the oxygen rate of the air and cause asphyxiation and suffocation. These are called suffocating gases. (Examples of suffocating gases are nitrogen, helium, argon, carbon dioxide.)
b- Toxic Gases
Some gases, on the other hand, connect our body through respiration or skin contact and cause poisoning with various biochemical effects. (Hydrogen sulfide, nitrogen dioxide, ammonia, carbon monoxide, chlorine are examples of common toxic gases.)
c- Flammable Gases
Another danger from gas is fire and explosions. Some gases burn in contact with a spark or heat source. Combustion can occur suddenly in the form of an explosion depending on the ambient conditions, causing great damage to human life or industrial facilities. (Methane, propane, butane, hydrogen are examples of common flammable gases.)