Using multiple hazard types (corrosive, flammable, toxic, etc.) together will generate mixed hazard material. When one of the hazards present is radioactivity, then the radioactive nature of the material usually takes regulatory precedent as far as the day-to-day use of the material is concerned. But when the time comes to dispose of this material, then all hazards present must be taken into consideration for final disposal purposes. In some cases, these considerations are negligible. Dry, solid radioactive waste usually will be incinerated, and most other hazards in a similar physical form can be incinerated safely. In the case of liquid mixed waste, however, each hazard type present must be taken into consideration when it comes time for its final disposal.
When a lab asks for EHS to pick up liquid radioactive waste, EHS staff always ask for the chemicals present. In most cases, they are told the solute present and sometimes the percent of the solute, but rarely the solvent used. Labs must inform EHS of the solvent used as well. This goes for both licensed radioactive material and unlicensed (natural uranium or thorium) materials.
Mixed hazard liquid waste is more expensive to dispose of. In addition, depending on the hazards present, there may be a limit to how long EHS is allowed to store them before their final disposal. Therefore, EHS needs to know the hazards present.
Labs that are generating liquid radioactive waste should contact EHS to evaluate whether the waste they are generating is a mixed hazard or not. Labs that are submitting new applications for the use of radioactive material should expect the possibility that their inspector or another EHS representative will be contacting them to ask questions about the waste they will be generating.
Customers are reminded that, when radioactive liquids are disposed of, whether this is licensed material or naturally occurring uranium or thorium, EHS needs to know all of the chemical present – solutes and solvents. Labs that are generating liquid radioactive material should contact EHS to evaluate what is being disposed of and determine the best way to dispose of it.
Please contact radiation.safety@osu.edu