Polychlorinated biphenyls (PCBs), manufactured in the U.S. until banned in 1979 under The Toxic Substances Control Act, are persistent environmental pollutants with carcinogenic properties.

Many surfaces are still coated with PCB-laden paints, posing problems for remediation and hazardous waste disposal.

AMTS paste being applied to an I-beam contaminated with PCB paint. Source: NASAAvailable physicochemical removal methods, such as media blasting, strip off PCB-tainted paint but create a new waste stream requiring treatment according to federal regulations. Incineration destroys the PCBs as well as the painted structure, preventing reuse.

An Activated Metal Treatment System (AMTS) engineered at NASA’s Kennedy Space Center extracts PCBs and breaks them down into benign byproducts while on the structure. No additional treatment for PCBs is required, and the treated surface can be reused following application.

The technology applies a solvent solution, such as ethanol or d-limonene, which contains an activated zero-valent metal. The solution is applied to the painted surface, using either spray-on or wipe-on techniques, to extract PCBs from the paint. Extracted PCBs react with microscale activated metal and are degraded into benign byproducts.

The treatment can be applied without removing the paint or dismantling the painted structure. AMTS works on painted structures; concrete surfaces contaminated by PCB-laden transformer oil, caulks, and other adhesives; electrical equipment; soils (ex situ); and other PCB-contaminated debris.