plumbing - Green and white stuff on copper pipes - Home ...
Wearing gloves, as copper chlorides are toxic, you can remove them with full strength vinegar or dilute muriatic acid, lemon juice or even more flux and a bristle brush. Once it's cleaned up, repair the leak or tighten the packing gland on the valve stem. Then when all done, just liberally apply a paste of baking soda and water.