Is it safe to proceed through an invisible cloud of ammonia?

It is not safe to proceed through an invisible cloud of ammonia because ammonia is a highly irritating and toxic substance. Exposure to ammonia can cause severe respiratory issues, eye irritation, and skin burns, depending on its concentration. The fact that it is invisible adds to the danger, as individuals are unable to see or gauge the presence of the hazardous gas, which could lead to higher levels of exposure than anticipated.

The correct answer reflects an understanding of the risks associated with ammonia exposure, emphasizing the importance of avoiding areas where toxic gases are present, regardless of their visibility. Safety protocols typically advise against entering any area contaminated with hazardous materials unless proper protective measures are in place, which are not guaranteed in this scenario.

Other choices may suggest circumstances where it might be deemed acceptable to proceed (like using a respirator or depending on concentration levels), but the primary concern is safety, which is compromised in the presence of such a harmful substance without sufficient safeguards.