Which practice is characteristic of inherently safer design?

• A. Substituting a less hazardous chemical for a more hazardous one.
• B. Increasing system complexity.
• C. Maximizing the number of manual operations.
• D. Relying on active rather than passive controls.

Answer: (A)

Substitution of a less hazardous chemical for a more hazardous one shows inherently safer design because the hazard is removed at its source rather than managed after it could cause harm. By choosing a chemical with lower toxicity, reactivity, or flammability, the potential consequences and likelihood of an incident are reduced without relying on complex safeguards or active controls.

Raising system complexity tends to introduce more failure points and make safety harder to assure. More manual operations increase exposure to human error and risk. Relying on active controls means safety depends on ongoing action and maintenance, whereas inherently safer design favors simpler, more passive protections and hazard reduction at the source.