Measurements are reported of the electrical resistivity and thermoelectric ratio of potassium samples encased in polyethylene or Teflon tubes, or in contact with Kel-F. The samples encased in polyethylene display Kondo-like anomalies below a few tenths of a kelvin in both the resistivity and the thermoelectric ratio. These anomalies are not present in the samples in Teflon tubes or in contact with Kel-F. The observed anomalous behaviour is consistent with some, but not all, of the unusual behaviour reported by previous observers for the resistivity in the vicinity of 1K of potassium samples in polyethylene.