The Trump administration has announced what it is calling “a major step forward” in the fight against a class of toxic chemicals called PFAS, or per- and polyfluoroalkyl substances. Extended exposure to PFAS, often referred to as “forever chemicals” because they can persist indefinitely in the environment, has been linked to various cancers, autoimmune diseases, and other harms.

On Monday, Secretary of Health and Human Services Robert F. Kennedy Jr. lauded Trump as the first president who is “completely committed” to removing forever chemicals, which are found at unsafe levels in tap water in some 80 percent of congressional districts and lurk in the blood of 97 percent of Americans.

But what Kennedy considers a step forward looks like a big step back to most of those who have long kept an eye on the issue. That’s because the Trump administration is unraveling key parts of the PFAS limits approved by the Biden administration in 2024, which are the first and only regulations to put limits on PFAS in drinking water in the nation’s history. Restrictions on four substances in the PFAS class would be rescinded entirely, while water utilities would be given two additional years to comply with limits for two other substances. The Environmental Protection Agency first signaled its intention to make these changes last year, just a few months after Trump took office. The changes will be finalized after a 60-day public comment period expires.