Martin Pleasance Tissue Salts Ferr Phos First Aid Cream 75g. Ferr Phos is known as the First aid remedy. It is found especially in red blood cells. It is regarded as the oxygen carrier. The more oxygen the cells receive, the more nutrients they can burn and the more energy they can release. Iron Phosphate-Ferr Phos plays a role in the creation of energy in the cells. It gives strength and toughness to the circular walls of blood vessels, especially the arteries. We must always remember that freely circulating oxygen rich blood is essential to health and life.