"The SDS includes information such as the properties of each chemical; the physical, health, and environmental health hazards; protective measures; and safety precautions for handling, storing, and transporting the chemical."-- OSHA Brief, Hazard Communication Standard: Safety Data Sheets (PDF)
They are a "component of the U.S. Occupational Safety and Health Administration’s (OSHA) Hazard Communication Standard. This regulation, announced in August 1987, requires employers to provide information to employees about hazardous chemicals used in the workplace through SDS, proper labels, and training programs” (Van Camp, p. 97). The regulation covers private, public, industry, and non-industry uses by any employee of any chemical that may have potentially harmful effects.
These resources don't contain SDSs but do contain information about chemical properties.