It is safer and more pleasant than traditional acids that are used for concrete cleaning. Congo has been developed to remove concrete and other calcium based soils without the corrosion issues associated with conventional products.
Geologist Friedrich STÖBER (1862-1933): PKs GENT 1898 about Jan de Wildt († Congo)
WMF G & Cross Paw Cross Hallmarked Metal Teapot Art Deco 1.25L
