Which of the following is NOT a safe practice when handling automotive fluids?

Mixing different chemicals is not a safe practice when handling automotive fluids because it can result in dangerous chemical reactions. Some automotive fluids and chemicals can be volatile or reactive when combined, potentially leading to explosions, fires, or the release of toxic fumes. For instance, mixing certain types of antifreeze with oil or gasoline can create hazardous reactions that not only endanger the person handling the fluids but also compromise safety in the working environment.

Using a funnel, storing fluids in locked cabinets, and keeping ignition sources elevated are all safety measures that help prevent spills, leaks, and ignition of flammable materials, thereby promoting a safer working environment when handling automotive fluids.