Final answer:
MOPP Level 0 is the condition when Sailors have their MOPP gear available but are not currently wearing it, indicating preparedness for a potential threat without immediate need for donning the gear.
Step-by-step explanation:
The condition that exists when a Sailor has all of his or her MOPP (Mission Oriented Protective Posture) gear available but is not wearing it is referred to as MOPP Level 0. This level indicates that a threat has been identified, and personnel should be prepared to don their protective gear quickly, but the situation does not yet warrant wearing the gear. MOPP levels are designed to ensure that service members can respond to threats of chemical, biological, radiological, and nuclear (CBRN) environments while balancing mission readiness and personnel protection.