Used x-ray filter solution contains a high amount of silver, and is therefore considered a hazardous waste, requiring it to be handled by a hazardous waste management company. Used x-ray fixer must never be flushed down the drain.
X-ray developer that is mixed with used fixer solution must also be disposed of through a dental waste disposal company. Unused developer contains a toxic substance called hydroquinone, which cannot be flushed down the drain. Both unused and used developer should also never be disposed of into septic systems, as it my cause them to fail.