SANTA FE, N.M. (AP) – Workers at the Los Alamos National Laboratory were contaminated after radioactive particles were released into the air inside the lab’s plutonium facility.

The Santa Fe New Mexican reports the lab accident last month was the second time in four weeks that the same crew was exposed to radioactive material. The clothes of three workers were contaminated as was the skin on one of them.

Lab spokesman Matt Nerzig says the three workers did not receive a measurable dose, and the public was not in danger. He says the worker with the skin contamination “was successfully and thoroughly decontaminated – mostly by washing off the contamination with water.”

A report by the Defense Nuclear Facilities Safety Board states the workers were wearing protective clothing and air purifying respirators.