Chemical Safety
Chapter 5 Unknown Chemical Disposal
The Division of Research Safety (DRS) is prohibited by the Illinois EPA from collecting unlabeled chemical containers. If you have unlabeled chemical containers in your workplace that you wish to dispose, you must either find the person who generated the substance and have them identify it, or perform the following screening procedures for each unlabeled chemical container.
Important pre-screening notices
Peroxidizable compounds such as ethers, dioxanes, tetrahydrofuran, etc., absorb and react with oxygen to form potentially explosive compounds with time. Exposure to air and light accelerates these formations. Therefore, if your unlabeled liquid has partially or fully evaporated and crystals are present (or the liquid has become unclear), label the container as "POSSIBLE PEROXIDE." DO NOT follow the screening procedures for this container, request assistance from the DRS Chemical Safety Section by calling (217) 333-2755.
On occasion, unlabeled chemicals contain radioactive materials. If you have access to a Geiger counter, check the container to determine if the material is radioactive. If radioactivity is found, DO NOT follow these procedures for this container, request assistance from the DRS Radiation Safety Section by calling (217) 333-2755.
On occasion, unlabeled chemicals could contain biological materials. If you have any reason to suspect a biohazard, DO NOT follow the screening procedures for this container, request assistance from the DRS Biological Safety Section by calling (217) 333-2755.
Safety considerations
For your safety, you should prepare for the worst by utilizing chemical resistant gloves, goggles, a face shield and/or a poly work shield. In addition to personal protective equipment, all screening work should be performed in an empty chemical fume hood. Since the procedure tests items for flammability, it is recommended that a functioning fire extinguisher be available in case of unexpectedly violent reactions. You should also be aware of the nearest fire alarm pull station, in case of an emergency. If you are uncomfortable performing these procedures, ask your supervisor to find a qualified individual in your department.
Description of screening procedures for unlabeled containers
Each unlabeled material is screened for the following: air reactivity, water reactivity, corrosivity, and flammability. Because of the small quantities involved for each unlabeled chemical container, a rigorous sampling method is not required. One test container (aluminum dish, evaporating dish, watch glass) can sometimes be used for all four steps of the screening procedures. Residues from the screening procedures may be disposed down the sanitary sewer (sink drain). When labeling the chemical container, do not cover the original label or any markings with the new label.
- Air reactivity
Pour a small amount (a few drops or crystals) of the unlabeled material into a test container inside the chemical fume hood. If the material is air reactive, a reaction will be apparent within 30 seconds and should be labeled "UI#7078-Characterized Waste-Air Reactive." If not air reactive, proceed to step two. - Water reactivity
Pour a small amount (a few drops or crystals) of the material into a test container inside the chemical fume hood. Using a wash bottle filled with water, add a few drops of water to the compound. If the material is water reactive, a reaction will be apparent within a few seconds. If reactive, label the container "UI#7079-Characterized Waste-Water Reactive." If not water reactive, proceed to step three.
Note: Steps 3 and 4 should both be performed if classification is not determined in steps 1 or 2. - Corrosivity
Obtain the pH of the sample using pH paper or a pH meter. Record the pH to the nearest whole number on the container label. - Flammability (Perform only on liquids)
Pour a few drops (maximum of three to four drops) of the material into a test container inside the chemical fume hood. Before proceeding, seal the original container of unlabeled material and remove it from the chemical fume hood. Light a match and hold it approximately 1-2 inches above the screening sample. If the material immediately starts burning, it is considered to be flammable. If the material has not started burning after a few seconds, it is considered to be not flammable.
Labeling containers
- If steps 1 or 2 are positive, label container as instructed above.
- If steps 1 and 2 are negative, label the container according to the following:
- If flammable and pH = 3-11: "UI#7080-Characterized Waste-Flammable"
- If flammable and pH = 2 or less: "UI#7083-Characterized Waste-Flammable, Acid"
- If flammable and pH = 12 or more: "UI#7084-Characterized Waste-Flammable, Base"
- If not flammable (or solid) and pH = 2 or less: "UI#7081-Characterized Waste-Acid"
- If not flammable (or solid) and pH = 12 or more: "UI#7082-Characterized Waste-Base"
- If not flammable (or solid) and pH = 3-11: "UI#7085-Characterized Waste-Other"
- Any other information about the contents of the container should also be shown on the container.
Pickup of screened containers
After containers have been labeled with the preceding guidelines, you may request that they be collected for disposal using ChemTrak form CWM-TRK-01: Request for Pickup of Chemical Waste. The UI# required on the form is listed with each of the above descriptive names. ChemTrak labels will be returned to be placed on the containers. Please do not cover the original label or any markings with this new label.
Contact the DRS Chemical Safety Section staff at (217) 333-2755 with questions or for additional assistance.
