Final answer:
The Hazard Communication Standard (HCS) requires employers to inform workers about chemical hazards on the job through training and other methods.
Step-by-step explanation:
The safety standard that requires all employers to notify their employees about chemical hazards present on the job and train employees to use these materials safely is the Hazard Communication Standard (HCS). According to OSHA, employers must inform workers about chemical hazards through training, labels, alarms, color-coded systems, chemical information sheets, and other methods.