This story was originally published by Undark and is reproduced here as part of the Climate Desk collaboration.

In the basement of the Center for Urban Innovation at Ryerson University in Toronto, a lone toilet sits on a raised, tiled platform. Darko Joksimovic, an associate professor of civil engineering, drops a clean bathroom wipe into the bowl and flushes. It swims down a 66-foot pipeline that includes two 90-degree turns and clears it in one go.

He then collects the soggy material and drops it into something called a slosh box. This clear tank agitates a gallon of water at a gentle 18 revolutions per minute for 30 minutes. When that’s done, Joksimovic rinses the wipe over a sieve with inch-wide holes for a minute. The material left on the sieve’s surface gets baked in an oven, and then weighed.

If 95 percent of the material slips away through the holes, Joksimovic will rate it as flushable.

This particular test is on a private-label wipe from a Canadian drug store chain. Only 13 percent of the wipe, which is labeled flushable and designed to be used in the bathroom instead of toilet paper, dispersed after this one-hour test. “It fails,” he says. “Everyone claims their products are flushable. What we are doing is testing these claims.”

Barry Orr, sewer outreach and control inspector for the city of London in Ontario, says many personal wipes don’t fall apart in sewers and can twist and become stronger, clogging pipes and sewer pumps, while attracting other materials to them, creating so-called fatbergs — congealed masses of flushed items that float, destructively, through sewers.

“Wipes are kryptonite — they should not be flushed,” says Orr, who worked with Joksimovic on a 2019 flushability study as a master’s student in environmental applied science and management at Ryerson.

That study tested 101 household products sold in Ontario, either in stores or online, including wipes, facial tissues, diaper liners, and dog poop bags — some of which claimed to be flushable — and found just 17 of them disintegrated to some degree after lab testing, while only the 11 conventional toilet tissues used as controls in the study fully disintegrated. For the research, Joksimovic and his team followed specifications set out by the International Water Services Flushability Group (IWSFG), whose members include the Canadian Water and Wastewater Association, its American counterpart, the National Association of Clean Water Agencies, and other national groups from Australia, Japan, Spain, and New Zealand, as well as a handful of regional organizations.

The Ryerson study, which was highly critical of flushability claims for consumer goods, is part of a wider dispute involving consumers, municipalities, the wastewater industry, and manufacturers of personal care and cleaning products. And there is little agreement among regulators and industry over standards and testing to assess which consumer products should be deemed flushable, and which should not. They sponsor and cite different field tests of the performance of wipes in real sewers. And they don’t agree on labeling compliance. Joksimovic and Orr work with the IWSFG, but other groups, including the Marine Conservation Society in the United Kingdom and Friends of the Earth Canada, have also spoken out against wipes and their makers’ flushability claims.

Manufacturers, meanwhile, have set their own standards, laid out in the fourth edition of the Guidelines for Assessing the Flushability of Disposable Nonwoven Products (GD4). The IWSFG’s specifications are “designed to fit their ideology that only pee, poop, and paper should be flushed,” says David Rousse, president of the Association of the Nonwoven Fabrics Industry, which goes by INDA and represents dozens of companies. “If every wipe flushed were a flushable wipe passing our GD4, there would be no problems in pipes caused by wipes.”

The group maintains that non-flushable baby wipes are the real culprits in clogging up sewers, and that wipes labeled flushable comprise a mere 2 percent of sewer clogs. They also say consumer education is the best fix.

Whatever the merits of the competing arguments, big money is at stake. The IWSFG estimates that municipalities in the U.S. spend between $500 million to $1 billion annually wrestling with fatbergs and unclogging pipes, sewer pumps, and other underground equipment. Manufacturers, meanwhile, make healthy profits from the expanding category of wipe products, which includes toilet paper replacements, baby wipes, as well as wipes designed for cleaning the house, for face and body washing, and for use after sex. One report from a product development company estimated the global market for these nonwoven wipes of all kinds to be $16.6 billion in 2018, with a growth rate of 5.7 percent a year, which would push the total to nearly $22 billion by 2023.

It’s been a back-and-forth feud in recent years, with both legislative and legal implications. For example, in December 2018, the Proctor & Gamble Company settled a class-action suit over its Charmin Freshmates Wipes, agreeing to pay up to $2.15 million in attorneys’ fees plus $1,000 to $5,000 to each of the 17 plaintiffs who accused the company of false advertising and causing them costly problems with their plumbing and septic systems. (The company did not admit liability in the settlement.) New Jersey is trying to legislate “do not flush” labels for products that fail flushability tests, and Canada’s Competition Bureau recently launched an investigation into manufacturers’ flushability claims.

Manufacturers have also won cases, including an injunction to block a proposed bylaw in Washington, D.C., that would have forced companies to prove their flushability claims, or not sell their products there.


The dispute began in the mid-2000s, as flushable wipes began to take up more shelf space in stores and sewers across North America started clogging more often.

Rob Villee, then executive director of the Plainfield Area Regional Sewerage Agency in New Jersey, recalls swapping stories of clogs and fatbergs with representatives from the National Association of Clean Water Agencies starting around 2010. “This became an issue that was being brought up by our members,” he says. “It was an emerging concern for everybody.”

Villee, who is now retired but says he’s become known in the wastewater industry as “lord of the wipes” for his research and advocacy on this topic, often works with Joksimovic and Orr, and also with Frank Dick, the industrial pre-treatment coordinator for the city of Vancouver, Washington. Around the same time Villee began encountering problems in New Jersey, sewer pumps in Vancouver began jamming up every few days. Dick, who was new to the industry at the time, asked veteran colleagues if this was normal. “They had not seen this before,” he recalls, adding that feminine hygiene products, paper towels, and greases had often made their way into sewers in the past, but “generally they didn’t cause the problems we see now.”

Early on, wastewater and industry groups worked together to find a process to assess flushability, aiming for an International Organization for Standardization (ISO) standard. “We could not come to an agreement,” says Orr. In 2008, INDA and its international affiliate released its first testing protocol, called GD1, which the wastewater industry quickly criticized as far too easy to pass — and concerns continued with the next iterations.

The GD4 came out in 2018, around the time the international flushability group finalized its own guidelines. The details differed, particularly with the slosh box test. The manufacturers’ GD4 stipulates half the amount of water, double the agitation time, and one-and-a-half times the speed as the IWSFG’s specifications. “This is not what sewers are like,” says Orr.

Rousse of INDA disagrees. The slosh box “is not meant to emulate any condition because a sewer system has no fixed condition,” he says. “If anybody can define what a typical sewer system dynamic is, that would be challenging because they vary all over the world.”

The GD4 also uses a smaller sieve and a rinse of two minutes instead of one, and considers a product to be flushable when 60 percent of it passes through the sieve, compared to the wastewater industry’s 95 percent threshold.

David Powling, a technical leader at Kimberly-Clark, says the IWSFG’s rules are stringent to a fault, even failing some ordinary toilet papers.

To bolster their claims that flushable wipes cause little harm in sewers, INDA and its members cite a 2016 study that collected debris from screens at two wastewater treatment facilities in New York City on a single day. It found that just over 1 percent came from flushable wipes, while 29.1 percent came from baby wipes. And earlier this year, Powling worked with the utilities provider for Jacksonville, Florida, on a similar one-day-collection study. It found flushable wipes made up only 1 percent of the debris found on screens near a wastewater treatment plant, while baby wipes comprised 37 percent.

Joksimovic points to flaws in both studies. Rain the night before the test in New York flushed the sewer system and likely distorted results, he says, and collecting samples in both cities near treatment plants, which are near the end of a sewer system, does not offer a full picture. “Wipes are not only causing problems at the downstream end, there are problems all the way,” he says. Joksimovic and others would like to see more collections on repeated days in different locations, and have them conducted by independent researchers.

Wastewater professionals point to a 2017 U.K. study that compared the composition of blockages taken from multiple sites and concluded that baby wipes made up 75 percent of identifiable debris, and other kinds of wipes and feminine hygiene products 20 percent. They also cite a 2017 German study that collected solids from two points in the Berlin sewer system over a year and found that only 14 percent of the debris came from wipes, though it didn’t distinguish the type.

In 2016, Dick conducted a study in Vancouver that entailed tagging individual products with pink duct tape and retrieving them later in the sewer system. He ran the test six times in different parts of city, and the results showed that while most brands of toilet paper disintegrated (some of the ones branded “extra strong” fared poorly), every brand of bathroom wipes other than Cottonelle did not, with some of them arriving at treatment plants nearly unchanged from when they came out of the package.

Beyond the disagreement over what is truly flushable and what’s not, there is quibbling about product labeling. INDA issued voluntary labeling guidelines in 2017, but wastewater professionals say manufacturers don’t use “do not flush” logos often or prominently enough on their packaging.

The Ryerson study of 101 items found 33 percent were labeled flushable. Of those that were not, 33 percent told consumers “do not flush” somewhere on the package while 25 percent used the “do not flush” symbol. But none followed INDA’s own rules for placing that logo in the appropriate location on the package, in a contrasting color, or in a large enough size.

Earlier this year, Orr did a separate study of 25 products, 22 of which did not meet INDA’s own standard of flushability, yet only eight were labeled do not flush, and none of those labels were in compliance with the code of practice. “No one is obeying the rules,” says Orr.

Rousse of INDA suggested that it’s a hard thing to track. “We don’t have a mechanism to police this,” he said. “What we do know is the majority of the major brands are largely in compliance.”

Meanwhile, companies aren’t required to list the materials used to make wipes on the package. Most baby wipes contain plastic, for example. Most bathroom wipes, in contrast, do not — but they often contain synthetics like rayon. “None of the packaging says that these baby wipes are made out of plastics or synthetic fibers,” says Villee, the former sewer agency director in New Jersey. He notes that the European Union is targeting plastic-containing baby wipes as a single-use plastic and may soon require labeling.

Both sides agree on one thing: The public needs to better respect sewers and toss disposable products in the garbage instead of the toilet. Municipalities are working to this end, with programs such as New York City’s $2 million “Trash It. Don’t Flush It” public awareness campaign.

As for the overall conflict over which wipes cause what harm, détente does not seem imminent. The wastewater industry argues that cities can’t keep wrestling with fatbergs while coping with more frequent flooding and other side effects of climate change. They also note that manufacturers are, on balance, settling more lawsuits — though wipe makers typically deny liability in these settlements.*

Manufacturers, meanwhile, have quietly begun to reformulate some of their products, making them more sewer friendly. (“We know the technology exists,” says Orr, who says he has tested wipes from Japan that fall apart as rapidly as toilet paper.) Powling of Kimberly-Clark, for example, says a recent overhaul of the company’s wipes has entailed using more paper-based materials. And Villee, who has few kind words for the makers of wipes, does say this: “In the seven or eight years I’ve been involved in this, we’ve seen huge improvements.”

*Correction: An earlier version of this piece incorrectly stated that wipe manufacturers have lost lawsuits over flushability claims made about their products. Rather, lawsuits have generally been settled prior to judgment, with manufacturers denying liability.