What principle underlies the concept of "substitution" in exposure control measures?

The principle of "substitution" in exposure control measures focuses on the practice of replacing a hazardous substance or process with one that is less harmful or presents a lower risk to health and safety. This approach aims to eliminate or reduce the source of exposure before relying on other control measures, such as engineering controls or personal protective equipment.

By substituting a hazardous substance with a safer alternative, the potential for exposure is minimized, which directly contributes to a safer working environment. This proactive strategy is foundational in various safety and health regulations, as it prioritizes eliminating the hazard rather than merely controlling or managing it after exposure has occurred.