What is a common characteristic of gases that are considered hazardous?

Gases that are classified as hazardous often possess the ability to be either flammable or toxic, which is a vital characteristic to understand, especially in fire training and hazardous materials response. Flammable gases can ignite and cause explosions or fires, posing a significant risk in various environments, particularly during firefighting operations. Toxic gases can affect human health, leading to serious health issues or fatalities upon exposure. Understanding this characteristic is crucial for firefighters and first responders to take the appropriate precautions and measures to protect themselves and those around them when dealing with hazardous materials.

Although some hazardous gases might share other traits, such as being heavier than air or being invisible, these characteristics alone do not define their hazard potential. For instance, not all hazardous gases are invisible or heavy, and while moisture absorption can occur, it is not a universal or definitive trait that affects their classification as hazardous. Therefore, recognizing the potential for flammability or toxicity offers a clearer, more comprehensive understanding of the hazards posed by these gases.