Is liquid soap in plastic containers less environmentally friendly than using a bar of soap?
The Sierra Club quotes Bill Chameides, professor emeritus and former dean of Duke University’s Nicholas School of the Environment, “Liquid soap has a bigger environmental footprint than a bar of soap.” He notes that its carbon footprint is at least 25 percent bigger than that of bars. Liquid soap requires plastic bottles and their pumps, which lead the typical user to extrude six or seven times as much soap by weight as the ornery, traditional bar-barian. However, Chameides also notes that bar users draw at least 30 percent more hot water than liquid aficionados.
Soap bars now account for only 30 percent of soap, bath, and shower product sales and have been slipping at a rate of more than 2 percent a year. People tend to believe liquid soaps are more hygienic, since many brands contain antibacterial chemicals like triclosan and triclocarban. The FDA, however, has reached a different conclusion: in 2016, the agency banned 19 of these chemicals (starting in 2017) because soap companies failed to prove that they are safe for long-term use or make soap more effective at cleaning.