Which material is considered hazardous waste?

Used cooking oil is considered hazardous waste primarily due to its potential environmental impact and risks to human health if not disposed of properly. When cooking oil is utilized, it can contain contaminants such as food particles, which may attract pests or promote bacteria growth. If this waste enters water systems or landfills, it can lead to severe pollution issues, including water contamination and harm to marine life.

In contrast, unbroken glass, plastic bottles, and scrap metal are typically recyclable materials that, while they may pose risks if broken, are not classified as hazardous waste in their intact forms. Recycling processes exist for these materials, allowing for resource recovery and minimizing environmental impact. Cooking oil, however, requires specific handling and disposal methods to mitigate its potential hazards, thus categorizing it as hazardous waste.