Disposal of Unlabeled or Unidentified Chemicals

The Illinois EPA prohibits the Division of Research Safety (DRS) from collecting unlabeled chemical containers. If you have unlabeled chemical containers in your workplace for disposal, ask the person who generated the substance to identify it or perform the following screening procedures for each unlabeled chemical container.

Important Pre-Screening Notices

Over time, peroxide-forming chemical compounds such as ethers, dioxanes, and tetrahydrofuran absorb and react with oxygen to form potentially explosive compounds. Exposure to air and light accelerates this process. Therefore, if an unlabeled liquid is partially or fully evaporated, and crystals are present (or the liquid has become cloudy), label the container as "POSSIBLE PEROXIDE." DO NOT attempt to screen this container; send an email to cws@illinois.edu or call 217-333-2755 to request assistance from the DRS.

Some unlabeled chemicals contain radioactive materials. If possible, use a radiation detection instrument to determine if the material is radioactive. If radioactivity is found, DO NOT attempt to screen the container; request assistance from the DRS by sending an email to rss@illinois.edu or calling 217-333-2755.

Unlabeled chemicals may contain biological materials. If you suspect a biohazard, DO NOT attempt to screen the container; request assistance from the DRS by sending an email to bss@illinois.edu or calling 217-333-2755.

Safety Considerations

Use chemical-resistant gloves, goggles, a face shield, and/or a poly work shield. Perform all screening work in an empty chemical fume hood. Because the procedure tests items for flammability, have a functioning fire extinguisher available in case of unexpected violent reactions. Locate the nearest fire alarm pull station in advance. If you are uncomfortable performing these procedures, ask your supervisor to find someone else to do them.

Screening Procedures for Unlabeled Containers

Each unlabeled material is screened for 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) may be sufficient for all four steps of the screening procedures. Residues from the screening procedures may be poured down the sink drain. When labeling the chemical container, do not cover the original label or any markings with the new label.

  1. 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 visible within 30 seconds, and the container should be labeled "UI# 7078–Characterized Waste–Air Reactive." If it is not air-reactive, proceed to step two.
  2. 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 visible 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.
  3. 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.
  4. Flammability (Perform only on liquids)
    Pour a 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 one to two 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

  1. If steps 1 or 2 are positive, label the container as instructed above.
  2. If steps 1 and 2 are negative, label the container as follows:
    • 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"
  1. Note any other information about the contents of the container on the container.

Pickup of Screened Containers


After containers have been labeled according to the preceding guidelines,
request a picked up on the DRS web site. The UI# and Chemical Name required on the DRS portal is listed above. DRS waste labels will be returned to be placed on the containers. Do not cover the original label or any markings with this new label.

If you have questions or need assistance, contact the DRS by sending an email to cws@illinois.edu or calling 217-333-2755.

Last Update: 9/1/2016