Which of the following is often referred to as the Worker Right-to-Know legislation?

The correct choice is OSHA's Hazard Communication Standard. This legislation is designed to ensure that information about the hazards of chemicals used in the workplace is communicated to employees, allowing them to understand potential risks and take necessary precautions. The Hazard Communication Standard requires employers to provide training on hazardous materials, maintain safety data sheets, and properly label hazardous substances. This directly aligns with the concept of "Worker Right-to-Know," as it empowers employees with the knowledge they need to work safely around potential chemical hazards.

In contrast, other options like the Occupational Safety and Health Administration's Enforcement Regulations and the Occupational Health and Safety Act pertain broadly to workplace safety and health standards but do not specifically focus on the communication of chemical hazards. The Employee Safety Information Act is less well-known compared to OSHA's regulations and does not typically have the same focus on chemical safety communication. Therefore, the Hazard Communication Standard distinctly embodies the essence of the Worker Right-to-Know legislation.