U.S. applications for jobless claims rose slightly last week but remain at healthy levels with companies reticent to let go of employees in a tight labor market.

The number of Americans filing for jobless claims for the week ending May 20 rose by 4,000 to 229,000 from 225,000 the week before, the Labor Department reported Thursday. The previous week’s number was revised down by a significant 17,000.

Analysts have pointed to a sustained increase in the four-week averages as a sign that layoffs are accelerating, but are reluctant to predict that a spike in layoffs is imminent.

Overall, 1.8 million people were collecting unemployment benefits the week that ended May 13, about 5,000 more than the previous week.

Rhode Island Attorney General Peter Neronha filed a lawsuit Thursday against the manufacturers of so-called “forever chemicals,” commonly referred to as PFAS, saying they have caused significant harm to the state’s residents and natural resources.

Neronha faulted the companies for engaging in what he described as “a massive and widespread campaign to knowingly deceive the public,”  manufacturing, marketing and selling hazardous chemicals for decades while knowing the risks.

The complaint, filed in Providence County Superior Court, alleges the companies violated state environmental and consumer protection laws.

Andrew Fasoli of the American Chemistry Council, an industry group, said not all PFAS are the same..

“We support strong, science-based regulation of PFAS chemistries. But overly broad restrictions on this important technology could significantly harm economic growth, cost countless jobs, damage supply chain resiliency, and hamper businesses and consumers from accessing the products they need,” he said in a statement.