Chemical storage is important because you always want to protect your chemical investment. It is best to store your chemicals in a controlled environment, such as room temperature or cooler. If the room temperature fluctuates constantly you run the risk of prematurely exhausting your chemicals; this is especially true for opened containers. It is also recommended to store your “working-solution” chemistry in airtight containers, to prevent early exhaustion.
For safety reasons we recommend you do NOT store your chemicals in ex-household or recycled containers, such as old milk or water jugs. We recommend brown chemical storage containers that you can label appropriately. We recommend such bottles because they prevent light from acting on your chemicals, they are specifically intended for chemical storage, and there is less chance of someone, particularly a child, mistaking the photo chemistry for something like lemonade or juice. Please take every precaution to protect yourself and others.
It is recommended that you store your chemicals below waist level to prevent spills or splashing of chemicals in the eyes.
In general, used darkroom chemicals, except fixer, may be disposed of in a municipal sewer system if one has a home-based darkroom. Used solutions should never be disposed of in a septic system. Septic systems are designed for biological treatment of standard household waste, and do not properly treat chemical wastes associated with photographic processing.
Photographic processing facilities, such as schools, labs, and professional photographers’ studios, must comply with stricter regulations than home users. Federal guidelines for waste disposal are usually administered by local/state/regional sewer authorities, who have the power to enforce those regulations. Managers of educational, commercial and professional darkrooms should begin by contacting such agencies to obtain guidelines.
Please note that some local regulations may be stricter than federal; they may require lower levels of chemicals in effluent. It may be necessary to obtain a permit from the local/state/regional sewer authority to discharge photolab effluents into the sewer line.
Used fixer, because it contains dissolved silver, requires special attention. For home-based darkrooms, there may be specific limits on the amount of dissolved silver allowed in effluent. Commercial users must process fixer in a silver recovery system or have it taken away by a waste disposal company. Remember, silver is valuable; there are ways for even small home users to recover it.