Immerse stained surface in fixer solution for about 30 s.

Fixer solution should be desilvered using a silver recovery unit.

Purchase a silver recovery unit to reclaim silver from the fixer solution.

Desilvered fixer solution may be safely disposed to sewer.

Silver containing wastes include spent X-ray developer and fixer solutions and undeveloped film.

• Separate developer and fixer solutions.

• Collect mixed developer/fixer solution in the container provided by an approved waste carrier or supplier.

Developer solution is basic and desilvered fixer solution is acidic.

• Contact the supplier about a take-back and recyling program for X-ray developer and fixer solutions.

To neutralize solutions, mix developer and desilvered fixer solutions or alternatively use a neutralizing agent prior to discharge.

All modern practical developers function primarily as non-physical developers, but this type of fog may be seen when developed film is brought directly into exhausted fixer solution.

Processing Chemistry Chemical speciation of photographic developer and fixer solutions, electrochemistry of development, silver potential and critical overpotential.

Since fixer solutions are acidic and developer solutions are basic, release of these solutions to the sewer are also subject to municipal bylaws for pH.

Alternatively, if fixer solution is not desilvered, collect the solution in a container labeled "X-ray fixer" and release to an approved waste carrier for recycling or disposal.

• Ensure that silver containing wastes and untreated spent X-ray developer and fixer solutions are not released to common waste streams (sewage system, biomedical waste or regular garbage).

Best Management Practices for the Disposal of Silver Containing Wastes in Ontario 1 Developer solution is basic and desilvered fixer solution is acidic.

Some municipalities also require the neutralization of fixer solutions prior to discharge since the acidity of fixer solutions can corrode copper drainage pipes.