👉 Fumes, which are airborne particles or vapors that can be hazardous to health and the environment, rely on several key assumptions to be considered valid. First, they must be present in the air in sufficient quantities to pose a risk; this involves the release of substances from various sources like industrial processes, vehicle exhaust, or chemical reactions. Second, these fumes must be chemically reactive or toxic enough to cause harm when inhaled or come into contact with surfaces. Third, exposure must occur through inhalation, as fumes are primarily inhaled and can quickly affect respiratory systems and other organs. Additionally, the duration and concentration of exposure are critical; short-term, high-concentration exposure can lead to acute effects, while chronic, lower-level exposure may result in long-term health issues. Finally, the assumptions include the ability to detect and measure these fumes accurately, ensuring that their presence and levels are known and understood to assess and mitigate risks effectively.