What is a potential issue with HEPA filters when they become clogged?

HEPA filters are designed to efficiently capture particulate matter, including dust, allergens, and pathogens, from the air. When HEPA filters become clogged, their effectiveness at filtering particles is compromised. As particulate matter builds up in the filter, airflow resistance increases, leading to reduced air exchange rates and insufficient filtration. This means that the air passing through the filter may carry a higher concentration of contaminants, defeating the purpose of using a HEPA filter in environments that require stringent air quality standards, such as laboratories or healthcare facilities.

In contrast, the other options do not accurately reflect the primary concern associated with clogged HEPA filters. Clogged filters do not directly cause explosions, they do not inherently increase humidity levels, and while they might impact room air circulation, they do not typically cause significant changes in room temperature. The most critical issue remains the reduced effectiveness in filtering particles, which is why the first option is the most relevant concern when discussing the maintenance and functionality of HEPA filters.