What term is used to describe man-made organic compounds that degrade very slowly?

The term for man-made organic compounds that degrade very slowly is "refractory organics." These substances are characterized by their resistance to decomposition through natural processes, making them challenging to break down in both environmental and wastewater treatment settings. Their persistence in the environment can lead to various ecological and health issues, as they accumulate and can have harmful effects on organisms that come into contact with them.

In contrast, other terms mentioned refer to different characteristics: "persistent organics" can describe substances that maintain stability over time but do not always indicate resistance to breakdown. "Biodegradable organics" refers to compounds that can be readily broken down by microorganisms into less harmful substances, thus not fitting the description of slow degradation. "Volatile organics" pertain to compounds that easily evaporate at room temperature, which is unrelated to their rate of degradation.