Phosgene gas is typically characterized by what appearance and odor?

Phosgene gas is typically recognized for being colorless or having a pale-yellow appearance and is known for its distinct odor that resembles freshly cut grass or hay. This characteristic scent is often noted during safety discussions around phosgene, as it can assist in early identification in low concentrations. Recognizing these traits is essential for individuals working in environments where exposure to phosgene might occur, as it helps in taking proper precautions to ensure safety. This knowledge is crucial in fields such as emergency response, hazardous materials handling, and various industrial applications.