It appears that this is a widespread issue done primarily for cost savings.
In HACCP or Preventive Controls training, we discuss the need to reevaluate your plan when new information becomes available. This would be the type of issue that when you learn about, you check to see whether this issue impacts your own operation. Perhaps you are buying imported oil roasted nuts or frozen pre-fried breaded chicken nuggets. Does this issue affect those items?
https://www.msn.com/en-us/news/world/china-is-freaking-out-over-an-open-secret-that-its-cooking-oil-was-ferried-for-years-in-chemical-tanks-that-weren-t-cleaned/ar-BB1pE693
China is freaking out over an 'open secret' that its cooking oil was ferried for years in chemical tanks that weren't cleaned
Story by mloh@businessinsider.com (Matthew Loh) • 15h
China has been hit by another major food scandal, this time involving cooking oil in chemical tanks.
https://www.msn.com/en-us/news/world/china-is-freaking-out-over-an-open-secret-that-its-cooking-oil-was-ferried-for-years-in-chemical-tanks-that-weren-t-cleaned/ar-BB1pE693
China is freaking out over an 'open secret' that its cooking oil was ferried for years in chemical tanks that weren't cleaned
Story by mloh@businessinsider.com (Matthew Loh) • 15h
China has been hit by another major food scandal, this time involving cooking oil in chemical tanks.