What is the maximum time allowed to don and clear a gas mask?

The maximum time allowed to don and clear a gas mask is indeed 9 seconds. This standard is set to ensure the safety and readiness of Marines in a chemical, biological, radiological, and nuclear (CBRN) environment. Quick and efficient donning of the mask is crucial, as exposure to hazardous agents can occur rapidly, and the ability to seal the mask properly within this timeframe directly affects the protection it provides.

Training emphasizes that Marines should be able to perform this task quickly, as delays can lead to serious health risks. The time is measured from the moment a Marine perceives the threat until they are fully prepared with the mask sealed against their face, ensuring that any air they breathe is filtered. Demonstrating proficiency in this skill is vital for maintaining operational readiness and survivability in dangerous situations.