answers: after World War II
context: Plumbing Plumbing is any system that conveys fluids for a wide range of applications. Plumbing uses pipes, valves, plumbing fixtures, tanks, and other apparatuses to convey fluids. Heating and cooling (HVAC), waste removal, and potable water delivery are among the most common uses for plumbing, but it is not limited to these applications. The word derives from the Latin for lead, "plumbum", as the first effective pipes used in the Roman era were lead pipes. In the developed world, plumbing infrastructure is critical to public health and sanitation. Boilermakers and pipefitters are not plumbers, although they work with piping as </s> processed food and drink, for example as a preservative in wine. Roman lead pipe inscriptions provided information on the owner to prevent water theft. Wooden pipes were used in London and elsewhere during the 16th and 17th centuries. The pipes were hollowed-out logs, which were tapered at the end with a small hole in which the water would pass through. The multiple pipes were then sealed together with hot animal fat. They were often used in Montreal and Boston in the 1800s, and built-up wooden tubes were widely used in the USA during the 20th century. These pipes, used in </s> first soft copper with flared fittings, then with rigid copper tubing utilizing soldered fittings. The use of lead for potable water declined sharply after World War II because of increased awareness of the dangers of lead poisoning. At this time, copper piping was introduced as a better and safer alternative to lead pipes. The major categories of plumbing systems or subsystems are: A "water pipe" is a pipe or tube, frequently made of plastic or metal, that carries pressurized and treated fresh water to a building (as part of a municipal water system), as well as inside the building. For
question: when did they stop using lead solder in plumbing