4 HP Designjet 9000s Series Printers Service Manual Waste ink is combustible. Keep an HP Waste Ink Bottle containing waste ink away from open flames, sparks, or other sources of ignition. Never store waste ink in a glass container. Never pour waste ink into a container filled with other chemicals. The HP Waste Ink Bottle contains organic solvents and must be disposed of in compliance with all local, state, and federal regulations. Always securely replace the cap on a full or partially-full the HP Waste Ink Bottle after removing it from the printer to prevent ink spills.