What type of emissions are considered 'fugitive emissions'?

Fugitive emissions refer to unintentional releases of gases or vapors from pressurized equipment due to leaks, usually occurring in industrial facilities. These emissions can arise from various sources such as valves, flanges, pumps, and other components where there may not be a completely sealed system. The defining characteristic of fugitive emissions is that they are not released through a designated exhaust system or stack, making them difficult to quantify and regulate.

The essence of fugitive emissions lies in their nature of being accidental and often difficult to measure or calculate compared to controlled emissions, which can be systematically managed. Recognizing the substantial impact that fugitive emissions can have on air quality and regulatory compliance, it becomes crucial for emissions inspectors to identify and assess these emissions during inspections so they can apply appropriate measures for reduction and control.

The other options do not encapsulate the definition of fugitive emissions accurately: controlled emissions refer to regulated and intentional releases, predictable and measurable emissions do not align with the accidental nature of fugitive emissions, and emissions from commercial aviation do not specifically pertain to the leaks in equipment or facilities that define fugitive emissions.