Proper Disposal of Testing Chemicals?

[Reefer_stc]

This may be a stupid question, but are there any "rules" to the proper disposal of testing chemicals? I know that many of the chemicals are at least caustic, or highly toxic/cancerous. I have been dumping down the drain for the last 5 years, but have often wondered if this is the correct way to do so. A friend of mind dumps his in his yard, which upsets me, and I try to convince him that he should not do so, as this is horrible for the environment, and goes straight to our drinking water, as well as dumping into streams and seas. Is dumping down the drain the way of proper disposal? Or are you supposed to collect and bring to a toxic waste facility? And is it good practice to rinse the drain before addition of different testing chemicals to avoid an unwanted reaction, or is this just my anxiety?
Thanks a lot,

Scott

 

[mcsassy]

Mine goes down the drain...never really thought of it as toxic.

 

[fsn77]

Dumping them down the drain is the generally accepted method for disposal. It is definitely best to run water before, during, and after pouring them down the drain to dilute the chemicals.

Collecting them for disposal by a suitable waste processing center would be so cost prohibitive that I doubt many people would actually do it. Unless keeping each test kit's resulting chemical mixture separate, it would most likely be considered "mixed waste" and quite expensive to dispose of properly.