ABS is a good material for pumps. It is a tough plastic that is resistant to heat, chemicals and impacts, and it is stable enough that it does not contaminate water supplies.
ABS stands for Acrylonitrile Butadiene Styrene. Consumers may be most familiar with it as the plastic used in Lego blocks.
ABS is very strong and is often used to build cases and housings for power tools, cameras and luggage. Its strength is ideal for outdoor pumps that are exposed to the elements. As a construction material, it is lightweight, less expensive than metal and easy to shape.
In addition, ABS does not corrode and does not leach chemicals into water. It is used in pipes and in water pitchers. Natural ABS and black ABS are both considered food safe by the FDA.