Which characteristic defines organic peroxides?

Organic peroxides are specifically characterized by the presence of a peroxy group, which is a chemical structure containing a bond between two oxygen atoms (-O-O). This unique structural feature is what distinguishes organic peroxides from other organic compounds. The peroxy bond adds to their reactivity and potential hazards, as it can decompose and release oxygen, leading to various reactions, including combustion and explosions under certain conditions.

The other options do not accurately capture the defining characteristic of organic peroxides. While some organic peroxides might not be explosive under specific conditions, many can be highly reactive; thus, stating they are non-explosive is misleading. Additionally, organic peroxides do not universally exist in a standard liquid state at room temperature, as some are solids and can vary in state based on their molecular structure. Lastly, characterizing organic peroxides as safe materials to work with is incorrect because they can pose significant risks, requiring careful handling and appropriate safety measures.