Which of the following is a primary safety concern related to hazardous substances?

The primary safety concern related to hazardous substances is that they can cause death or injuries. This is fundamentally important in any context where hazardous materials are involved, particularly in underground mining and industrial environments.

Hazardous substances include a wide range of chemicals and material that can pose serious health risks, such as toxicity, corrosivity, reactivity, and flammability. Exposure to these substances can lead to acute or chronic health problems for workers, including respiratory issues, skin irritations, and, in extreme cases, fatal accidents.

By focusing on the potential for serious health consequences, this perspective emphasizes the need for strict safety protocols, proper training, and effective personal protective equipment (PPE) to mitigate these risks. Ensuring the safety of workers from hazardous substances must always be the top priority in any operation where they are present.

While the other options touch on aspects that might concern operations, such as transportation difficulties, the physical state of the substances, or handling costs, these factors are secondary when assessing the immediate safety implications for individuals working with or around hazardous materials.