††The first successful fridge was developed in 1876 by Karl Paul Gottfried. James Harrison had introduced a less successful version 15 years earlier. When electric fridges appeared the greatest problem lay in finding a safe substance to cool them down. Early substances, such as ammonia, were found to be poisonous. Freon, a non-toxic replacement, was later found to damage the ozone layer. In 1991 Germany became the first country to develop a fridge which was environmentally friendly.
