What might indicate the presence of a highly volatile chemical?

The presence of a highly volatile chemical is often indicated by a strong odor and negative air pressure. When a chemical is volatile, it readily evaporates into a gas, which can create a noticeable odor as it disperses into the air. The strong scent can be a warning sign that the chemical can easily transition from liquid to vapor, which is a concern for both health and safety.

Negative air pressure in the surrounding environment can be an important factor, as it might indicate that air is being drawn into a confined space from the outside. This is significant because it suggests that there could be an influx of vapors from volatile substances, potentially increasing the risk of exposure or explosion if they accumulate.

Other options do not typically imply the presence of volatile chemicals. Clear water and safe surroundings can suggest a lack of hazardous materials; a calm atmosphere with no odor might indicate an absence of chemical vapors, as would stable containers and clearly labeled materials. Hence, the combination of a strong odor alongside negative air pressure serves as a clear alert regarding the potential hazardous nature of volatile chemicals.