Of the six potential problems, which one is the most important?

• The lack of knowledge regarding the risks of transporting certain products;
• The lack of hazmat training by employees at a retail store;
• The difficulty in applying hazmat regulations to reverse logistics shipments;
• The different packaging(s) other than the original packaging being used to ship the material;
• The potential for hazmat to be subject to Environmental Protection Agency (EPA) waste manifest rules;
• Including items once classified as consumer commodities no longer meet the "consumer commodity" definition.