1. Regularly check the iron drums for corrosion, bumps, defects, dents, and leaks. Put the defective iron drum in a separate secondary packaging drum or leak emergency drum.
2. Make sure that the iron drum has its own suitable lid and is well sealed.
3. Identify the waste oil drum.
4. Make sure that the iron bucket and its contents are compatible. For example, don't put acid in ordinary iron buckets or put solvents in plastic buckets.