Which of the following substances is considered hazardous?

The correct choice identifies a substance that poses an unreasonable risk to health as hazardous. In the context of environmental safety and public health, a hazardous substance is defined by its potential to cause harm. This can include toxic chemicals, pollutants, or any material that poses a significant risk to human health or the environment.

Clean water is typically considered safe and beneficial for health, while paper waste is usually not classified as hazardous since it’s a biodegradable material that can be recycled. Organic fertilizer, although it can have environmental impacts if misused, is not inherently hazardous and is often utilized safely in agricultural practices. On the other hand, a substance that presents an unreasonable risk to health encompasses a broad range of chemicals or materials recognized due to their potential dangers and therefore is clearly identified as a hazardous substance.