However, F.D.A. officials and industry executives said they remained confident that most cosmetics sold in the United States — imported or made domestically — were safe.
Of the three million imported cosmetics shipments, the agency physically inspected just 9,871, or about 0.3 percent, last year. It picks those products it has reason to believe might have problems, often based on past checks of material from the same company. The letter said that 15 percent of those inspections resulted in what the F.D.A. calls “adverse findings.”
Laboratory tests were conducted on a smaller sample of those shipments — a total of 364 last year — and 20 percent of those led to adverse findings. The agency found bacterial contamination, illegal color additives that can cause skin or eye injuries, ingredients that were not on the label as required, and unsafe chemical substances like mercury, the agency said.
About 2,000 shipments a year are refused entry to the United States, based on these inspections or other issues; the highest share of those blocked come from China, India, South Korea, Canada and France, the letter said. Imports from China were particularly problematic — as has historically been the case with other products, including children’s toys. Cosmetics imports from China have jumped 79 percent over the last five years, the letter says.
For example, samples examined by the F.D.A. of a Chinese-made product called Kleancolor Frameous Lash & Brow, which sells for just $1, contained hazardous levels of mold, given that its intended area of use was the eye. The F.D.A. also found dangerous levels of mercury — it can cause kidney and nervous system damage — in a product made in Mexico called “Crema Piel De Seda,” or “Silky Skin Cream.” It was marketed to whiten skin, treat acne and remove various skin blemishes.
An F.D.A. official, who spoke on the condition of anonymity, said the real problem was that the agency has no way of knowing how widespread the problem is with imported cosmetics, given that it is doing so few inspections. But she said that the agency inspects only imported cosmetics it has a reason to suspect might have problems, which inflates the rate of adverse findings. The 20 percent adverse-findings figure does not mean that the problem is that widespread in imported cosmetics over all.
“The F.D.A. believes that the vast majority of cosmetic products on the market are safe, but our information on the universe of cosmetics is limited,” said Linda Katz, director of the office of cosmetics and colors, in a written statement.
Mr. Pallone, in an interview, said that the data the F.D.A. provided could help convince Congress to take up legislation to strengthen regulation of imported cosmetics. The idea has been embraced by some congressional Republicans as well as many major companies in the industry, who could benefit if cheap imports (including sometime counterfeits of their brand-name products) are subject to more scrutiny.
“The time is ripe to deal with the cosmetic issues, given the problems with imports,” Mr. Pallone said. He intends to reintroduce his proposal to expand the regulation of cosmetics, including imports, as part of a larger bill that would fund greater oversight of over-the-counter drugs.
Lisa Powers, a spokeswoman for the Personal Care Products Council, which represents the nation’s largest cosmetics makers, declined to comment on F.D.A. statistics regarding problems found with imported products, saying she had not seen the agency letter.
Craig Weiss, an executive at the Consumer Product Testing Company, which does thousands of tests a year on cosmetics products on behalf of companies in the industry, said he questioned how serious the health threat was, as most of the issues the F.D.A. finds were minor — for instance, labeling flaws or the use of color additives that happen not to be approved in the United States.
But he agreed that federal regulations might help the industry. “I have no issue with the F.D.A. upping the game,” he said. “It would stop the craziness and the attacks from the consumer activists.”
For now, President Trump’s 2018 budget proposal for the F.D.A. would slash spending for cosmetics imports testing from the roughly 10,000 conducted last year to about 1,600, which has angered consumer advocates.
“We are flying blind,” said Scott Faber, a lobbyist at the Environmental Working Group. “And until we have the rules and resources that enforce them, we will continue to be flying blind.”