What factor is NOT a criterion for hazardous waste classification?

The classification of hazardous waste is determined by specific criteria outlined in environmental regulations, which aim to identify materials that could pose a risk to human health or the environment. The correct answer identifies "size" as a factor that is not part of these criteria.

Ignitability, toxicity, and corrosivity are all key characteristics that can render materials hazardous. Ignitability relates to the ability of a waste to catch fire easily, toxicity refers to the potential of a substance to damage human health or the environment when released, and corrosivity describes the ability of a waste to corrode materials or human tissue. These criteria are essential for assessing whether a material should be classified as hazardous.

In contrast, the physical size of the waste does not affect its classification as hazardous. Regardless of how large or small a waste material is, if it meets any of the established criteria for ignitability, toxicity, or corrosivity, it can still be classified as hazardous. Therefore, size is not relevant in determining hazardous waste status, making it the correct choice for this question.