Employees and customers working with concrete must be informed of its health hazards. These hazards, and precautions, are presented in a material safety data sheet (MSDS). OSHA requires that producers furnish an MSDS to their customers and employees. Companies must furnish an MSDS with their first shipment and the first shipment after a material safety data sheet is updated. The National Institute for Occupational Safety and Health has prepared a complete MSDS on ready mixed concrete that producers can offer to customers. KEYWORDS: cement burn, MSDS, safety, silicosis