Sal was born in 1922 in Centaburgo, a prefecture of Castelmagno to Geremia Sal, the eldest son of Adamo Sal, former Mayor of Castelmagno (1916-1920), and Anna Sarmoni, a farmer. From 1933 to 1946, he and his family lived in the United States, in fear of a possible Jewish prosecution in Lecrotia. When World War II was over, the family went back to Lecrotia, while Erminio stayed there to finish the Psychology course; he later went back in 1951.