The Food and Drug Administration (FDA) is suspending a quality-control program for its food-testing laboratories as a result of staff cuts at the Department of Health and Human Services (HHS), according to an internal email seen by Reuters.

The proficiency testing program of the FDA’s Food Emergency Response Network is designed to ensure consistency and accuracy across the agency’s network of about 170 labs that test food for pathogens and contaminants to prevent foodborne illness.

The firing and departure of as many as 20,000 HHS employees has upended public health research and disrupted the agency’s work on areas such as bird flu and drug reviews. Donald Trump hopes to slash as much as $40bn from HHS.

“Unfortunately, significant reductions in force, including a key quality assurance officer, an analytical chemist, and two microbiologists at FDA’s Human Food Program Moffett Center have an immediate and significant impact on the Food Emergency Response Network (FERN) Proficiency Testing (PT) Program,” said the email sent on Tuesday from FERN’s National Program Office and seen by Reuters.

The program will be suspended at least through 30 September and means the agency will be unable to do planned quality-control work around lab testing for the parasite cyclospora in spinach or the pesticide glyphosate in barley, among other tests, the email says.

“These PTs and Exercises are critical to demonstrating the competency and readiness of our laboratory network to detect and respond to food safety and food defense events,” the email says.

HHS did not immediately respond to a request for comment.

A former FDA official told CBS News: “There’s so much work to go around. And us duplicating their work just doesn’t make sense.” The outlet further reported that the FDA is devising plans that would halt most of its routine food safety inspection work, citing multiple federal health officials.

According to the officials who spoke to the network under anonymity, the plans may need congressional action to fully fund, adding that some higher-risk routine food inspections would probably remain at the FDA.

Food safety laboratories rely on these types of tests to meet standards for accreditation, said a source familiar with the situation, who was not aware of other ready alternatives to the FDA to provide such testing.

The FDA in early April suspended an effort to improve its testing for bird flu in milk, cheese and pet food as a result of staff cuts.

In February, HHS announced plans to fire 5,200 probationary employees across various agencies including the National Institutes of Health, the FDA and the Centers for Disease Control and Prevention.

The same month, Jim Jones, the head of food division at the FDA, quit in protest against the staff cuts. At the time, Jones said: “I was looking forward to working to pursue the department’s agenda of improving the health of Americans by reducing diet-related chronic disease and risks from chemicals in food.”

He went on to add that the cuts would make it “fruitless” to continue in his role under the Trump administration, which he said has “disdain for the very people” needed to ensure food safety.