Plastic treatment with bases

A process comprising:

• heating a waste plastic stream having waste plastic to between 80° C. and 225° C. to form a softened plastic stream, the waste plastic stream including an impurity, the impurity being a haloorganic compound, an organosilicon, an organometallic or an inorganic compound of fluoride, chloride, bromide, iodide, iron, sodium, potassium, calcium, magnesium, titanium, manganese, vanadium, zinc, nitrogen, phosphorus, silicon, sulfur, selenium, antimony, tin, germanium arsenic, aluminum, copper, chromium, nickel, cobalt, molybdenum, barium, strontium, lead, cadmium, mercury, silver, gold, palladium, and platinum, an organophosphorus, an organosulfur, an oxygen containing organic compound, a nitrogen organic compound or a combination thereof;
• contacting the softened plastic stream with an aqueous alkaline base stream to form a reacted plastics mixture having a reacted impurity therein;
• and
• separating the reacted plastics mixture into a treated plastic stream having a treated plastics phase and an aqueous phase, wherein at least a portion of the impurity is present in the aqueous phase.