The approved method of disposing of PCBs is:

High-temperature incineration is the approved method for disposing of Polychlorinated Biphenyls (PCBs) due to its effectiveness in breaking down harmful compounds. PCBs are known for their toxic and persistent nature in the environment, leading to significant health and ecological risks. When incinerated at high temperatures, typically above 1,100 degrees Celsius, PCBs can be destroyed, resulting in the formation of less harmful byproducts.

Regulatory agencies like the Environmental Protection Agency (EPA) recognize high-temperature incineration as a safe method to handle PCBs, ensuring that they do not leach into soil or water sources where they could cause long-term environmental and health impacts. This process not only effectively eliminates the toxic constituents of PCBs but also adheres to stringent environmental regulations aimed at preventing contamination and protecting public health.

The other disposal methods mentioned, such as burial in landfills or detoxification for ocean discharge, do not reliably eliminate the toxic properties of PCBs and may lead to further environmental contamination. Biodegradation approaches are also not viable for PCBs due to their chemical structure, which resists biological breakdown, making high-temperature incineration the most effective and approved option for safe disposal.