Why can you not rely on senses alone to detect hazardous materials?

• A. Some hazardous materials may have a specific smell, while others have no odor at all
• B. All hazardous materials have strong odors
• C. Odor is always a reliable warning
• D. Color change is a sufficient indicator

Answer: (A)

Relying on senses alone to detect hazardous materials is unreliable because odor alone cannot reliably indicate danger. Some hazardous substances have a distinct smell, but others are odorless, or their odor may be masked by cleaners, fragrances, or environmental factors. Even when a chemical does have an odor, it doesn’t tell you how dangerous it is or at what concentration it becomes harmful. People’s ability to detect smells varies, and odor perception can fade with exposure, leading to odor fatigue. In short, odors are non-specific, variable, and not a dependable measure of hazard, so you must rely on proper detection equipment and procedures rather than your senses.