In 2021, experts retained by Charleston Water System tested whether seven leading personal wipes sold in the U.S., marketed as being flushable, would actually dissolve in sewer systems. Each “flushable” wipe was tested using the Publicly Available Specification (PAS) 3: 2020 Disintegration Test Methods – Slosh Box procedure, developed by the International Water Services Flushability Group (IWSFG). IWSFG is an international partnership of wastewater services associations and organizations, and individual wastewater utilities.
IWSFG tests whether or not wipes adversely impact drain lines, onsite treatment, and wastewater collection and treatment systems and the downstream environment, by subjecting wipes to the conditions typically found in wastewater transport systems, after a product is flushed.
The test measures how much of a wipe dissolved during the test and passed through a drain with one-inch openings. The higher the result means the greater amount of the wipe dissolved and passed through the one-inch drain openings. IWSFG requires an average of 80 percent of a wipe to dissolve and pass through the one-inch openings to be considered “flushable”.
CWS arranged for wipes from seven companies to be purchased in both the Charleston area as well as in New York for testing. Products from two geographic areas of the country were tested to identify any variability in the dissolvability of the products.
The results of CWS testing can be found here. Only the Cottonelle wipe passed the IWSFG 2020 standard of 80 percent dissolvability.