Smog Posted on 21st December 20157th May 2021 by ThePD (The Project Definition) Smog is fog or haze intensified by smoke or other atmospheric pollutants that is a mixture of smoke, gases, and chemicals. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in HSE and tagged environment, gas. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.