What does "Gray Water" refer to in aviation terminology?

In aviation terminology, "Gray Water" refers to non-consumable water, typically originating from sources such as sinks, showers, or lavatories on an aircraft. This water has been used and could contain contaminants, making it unsuitable for drinking or other consumptive purposes. It’s important to distinguish this type of water from consumable water, which is safe for drinking and cooking.

Understanding this distinction is crucial for the management of water systems onboard aircraft. Gray Water must be properly contained and treated to prevent contamination and ensure cleanliness within the aircraft environment. The management of gray water is part of maintaining safety and hygiene standards on flights.