Factories all across America churn out tons of products in large quantities every day. During the production process, many materials need to be blended or mixed together. These materials could include explosives, chemicals, color pigments, animal feed, a variety of liquids, and even tobacco. Mixing and blending machine operators are the people in charge of using large industrial machines to safely and effectively carry out this blending process. They set up, inspect, tend, and operate the machines. This job may require employees to deal with dangerous materials. Once hired, an employer usually requires up to a year of formal on-site job training before an employee can start work.