Material Safety Data Sheet. A document designed to inform users about the hazards possible when working with certain substances, primarily chemicals. One of many websites. MSDSs must be made available by employers for their employees under the US OSHA Hazard Communication Standard (see Title 29 Code of Federal Regulations 1910.1200). MSDSs are created by the manufacturer and are obtained from the manufacturer or person selling the product. Because MSDSs are regulated under labor laws, MSDSs are not typically provided for a household consumer purchase of a hazardous material at a store (although MSDSs are often available at the store).