Safety concerns at a prominent military germ lab have led the government to shut down research involving dangerous microbes. Research is currently on hold," the United States Army Medical Research Institute of Infectious Diseases, in Fort Detrick, Md., said in a statement. The Centers for Disease Control and Prevention decided to issue a "cease and desist order" last month to halt the research at Fort Detrick because the center did not have "sufficient systems in place to decontaminate wastewater" from its highest-security labs. The C.D.C. cited "national security reasons" as the rationale for not releasing information about its decision. The institute is a biodefense center that studies germs and toxins that could be used to threaten the military or public health, and also investigates disease outbreaks. The problems date back to May 2018, when storms flooded and ruined a decades-old steam sterilization plant that the institute had been using to treat wastewater from its labs. The damage halted research for months, until the institute developed a new decontamination system using chemicals. The new system required changes in certain procedures. During an inspection in June, the C.D.C. found that the new procedures were not being followed. Inspectors also found mechanical problems with the chemical-based decontamination system, as well as leaks. In 2009, research at the institute in Fort Detrick was suspended because it was storing pathogens not listed in its database.