While performing the duties of this job, the employee is occasionally required to stand; walk; sit; use hands to feel, or handle objects, tools or controls; reach with hands and arms; climb stairs; balance; stoop, kneel, bend, crouch or crawl; and talk or hear. Martin Marietta's Magnesia Specialties business produces high-purity magnesia and dolomitic lime products used worldwide in environmental, industrial, agricultural and specialty applications.