The quality of lubricating oil is closely related to the physical and chemical conditions during storage and transportation, and the major problem lies in cross contamination between different oil products, especially when repackaging and using new oil drums. Special attention should be paid to the cleanliness of oil drums. The following are precautions for purchasing lubricating oil:

1. Is there a quantified cleanliness standard for oil drums during the packaging process?

2. Is the interior of the oil drum inspected before filling? Are there corresponding inspection standards?

3. Has a pressure test been conducted on the oil drums before filling to check their load-bearing capacity?

4. Is the oil drum stored in a dry and clean (dust-free) environment?