At the time, these devices were thermodynamically speaking quite advanced, but they used toxic chemicals such as ammonia, methyl chloride, or sulfur dioxide as their coolant fluid. Refrigerator pumps, if their seals leaked, would release these toxic chemicals into their owners’ homes with devastating consequences. In 1926, Einstein had read a harrowing newspaper account of one Berlin family, including several children, who had died from the fumes emanating from their malfunctioning refrigerator. The story prompted Einstein to try to design a safer one.
