Drain Disposal of Chemicals
Before considering drain disposal, be certain that the sewer flows to a wastewater treatment plant and not to a stream or other natural water course
Before considering drain disposal, be certain that the sewer flows to a wastewater treatment plant and not to a stream or other natural water course. Check with the local waste water treatment plant authority to determine what substances are acceptable for drain disposal.
- Any substance from a laboratory should be flushed with at least 100 times its own volume of tap water.
- Acids and bases should be at least above pH 3 and below pH 8 before being placed in a sanitary drain.
If both ions of a compound are on the following lists, that compound may be placed in a sanitary drain:
| Positive Ions | Negative Ions |
| aluminum | borate |
| ammonium | bromide |
| bismuth | carbonate |
| calcium | chloride |
| copper | cyanate |
| hydrogen | hydrogen sulfide |
| iron | hydroxide |
| lithium | iodide |
| magnesium | nitrate |
| potassium | phosphate |
| sodium | sulfate |
| strontium | sulfite |
| tin | tetraboratex |
| titanium | thiocyanate |
| zinc | |
| zirconium |
The following organic compounds can go into a drain:
| acetic acid | acetone |
| butanols | esters with less than five carbon atoms |
| ethanol | ethylene glycol |
| glycerol | methanol |
| oxalic acid | pentanols |
| propanols | sodium salts of carboxylic acids |
| potassium salts of carboxylic acids | formic acid |
| sugars |
For additional information on drain disposal of substances, see the National Research Council’s Prudent Practices in the Laboratory (1983).
The following website offers more information on this topic: http://www.nap.edu - National Academies Press
If in doubt about the proper disposal of a chemical, check with the local safety officer or refer to Flinn or a similar reference.
Compounds Not Suitable for Drain Disposal
For compounds not suitable for drain disposal, label and package the compound and ship by a shipper approved by the U.S. Department of Transportation to a landfill designated by EPA to receive chemical and hazardous waste. Even though packed, shipped, and disposed of by licensed and approved firms, generators of hazardous waste are responsible for the wastes.