Unknown Chemical(s) Guidance

An unknown is defined as a chemical in an unlabeled container for which the identity is undetermined.  Federal, state, and local regulations all specifically prohibit the transportation, storage, or disposal of unknown wastes. In addition, hazardous waste disposal companies will not accept unknowns without proper analysis. Therefore, unknown or unlabeled chemicals all require analysis prior to disposal, which can easily cost $1,000 or more for a single sample.  Unknown chemicals present serious legal and safety problems for the University.

Unknown Testing Procedures 

All tests performed should be conducted in a functioning fume hood. Use as small a sample as reasonably possible while performing the tests. The results of each test should be noted on the hazardous waste tag prior to pick up by EHS.

Test #1 – Water Miscibility/Reactivity

This test is to determine if the unknown material reacts with water, and also whether the material is soluble in water, or whether it sinks or floats when added to water.

Test #2 – pH

Picture show the pH scale from 0 to 14 with number and color references for the MQuant pH indicator strips. 

Liquid – Dip the pH paper into the unknown liquid and compare the test strip to the pH chart on the container.  Note the results of the test on the hazardous waste tag attached to the unknown.

Example: Unknown liquid has a pH of 0 indicating an acidic solution

Picture with a pH indicator strip showing a pink 0 pH reading after being dipped into liquid unknown.

Solid – If material from has been determined not to be water reactive, place a small amount of the solid material on a watch glass with enough deionized water to dissolve or wet the solid and dip the pH strip into the solution.  Note the results of the test on the hazardous waste tag attached to the unknown.

Example: pH strip being dipped into unknown solid/water solution

 Picture showing watch glass containing unknown white solid and deionized water.  Lab personnel are dipping the pH indictor strip into the solution on the watch glass.

Test #3 – Flammability