Between gas in the pipes and arsenic in the paint and wallpaper, households in the 1920s packed more than their share of deadly substances. Thus it seems appropriate that the transition from the traditional icebox (literally, an insulated wooden box with ice in it) to electrical refrigerators added to the peril by occasionally leaking volatile chemical coolants like methyl chloride, ammonia or sulfur dioxide to poison hapless homeowners.
One such incident in 1926 inspired Einstein to enlist the help of Hungarian physicist Léo Szilàrd in designing a new kind of appliance called an absorption refrigerator that required only ammonia, butane and water, plus a heat source for the pump. Patented in 1930, their device relied on the principle that liquids boil at lower temperatures when exposed to lower atmospheric pressures. As pressure in the pipe above the butane reservoir dropped, the butane would boil off, drawing in heat from its surroundings and lowering temperatures in the fridge. Because it had no moving parts, the appliance would last as long as its casing [sources: Jha].
Einstein and Szilàrd's refrigerator lost out to more efficient competitors and to the introduction of chlorofluorocarbons, which replaced more hazardous coolants and rendered the compressor fridge safer for people, if not the ozone layer. But new technologies and growing environmental concerns have today sparked renewed interest in their approach, particularly as a means of providing refrigeration in remote and rugged areas.