ABS stands for acrylonitrile butadiene styrene, which probably doesn’t mean much to the Average Joe, but is a generally low hazard material presenting few risks to humans. That and its toughness make for a competitive plumbing material to PVC pipe. Even though ABS is stronger than PVC, it’s also flexible and lightweight, making it ideal for fitting into small spaces. Moreover, ABS is easier to install than PVC, which needs primer before glue to form a bond and takes more time to dry, allowing for connections to push apart. The downsides? ABS is more likely to deform under sun exposure, costs more, and may not be available at all home improvement retailers.