I uses the principles of chemistry, biology, physics, and math to design, develop, and optimize chemical processes and equipment for the production of chemicals, fuels, foods, and many other products. They are responsible for creating efficient and cost-effective methods of manufacturing, as well as ensuring the safety and environmental impact of these processes. I responsible for creating efficient and cost-effective methods of manufacturing, as well as ensuring the safety and environmental impact of these processes. Chemical engineers work in a variety of industries, including petrochemical, pharmaceutical, and food processing.