Using which human senses to determine the presence of hazardous material is considered unsafe?

Using smell or taste to determine the presence of hazardous materials is considered unsafe due to the potential health risks involved. Many hazardous substances can have no detectable odor, while others might have odors that are misleading or indicative of danger. Relying on these senses could lead to exposure to harmful chemicals or gases that can cause severe health effects or even fatalities.

For instance, some toxic gases can cause symptoms before a person can detect them by smell, while others may have a strong odor at low concentrations but become odorless at higher, more dangerous levels. Taste is not a typical or reliable method for detecting hazardous materials, as ingesting or coming into contact with harmful substances can pose immediate health dangers. Therefore, safety protocols and training emphasize using other methods, such as specialized equipment, rather than relying on these senses.