Federal homeland security and public health officials plan to draft guidelines by next year for assessing chemical, biological, radiological and nuclear threats.

Currently, departments of Homeland Security and Health and Human Services assess such threats on an ad hoc basis. But they lack a formal arrangement — something congressional auditors said in a June report is needed to “better ensure coordination, collaboration, and continuity beyond the tenure of any given official or individual office.”

“Given the turnover of those occupying top positions in many federal agencies, it is important that those new to these key positions have a document to which they can refer that describes their roles and responsibilities in the process of developing and reviewing the risk assessments,” said Bill Jenkins, co-author of the June report by the Government Accountability Office said in an email.

DHS had earlier promised to strike a written agreement on how the two departments would cooperate by this year, but it has delayed that until June 2012.

“Understandably, the development of complex, resource-intensive products will benefit from fully defined processes to ensure all relevant information is appropriately incorporated,” DHS spokesman Adam Fetcher said.

In the GAO report, Health and Human Services officials said they want to be more involved from the beginning when deciding what potential chemical, biological, radiological and nuclear (CBRN) agents are most threatening to U.S. security. The department is responsible for stockpiling medical countermeasures to be used in the event of a CBRN disaster. Currently, DHS provides HHS with a laundry list of what medical countermeasures are most pressing to have in stock.

“Based on that determination, we seek and fund private-sector research and development of medical countermeasures, and stockpile and distribute those countermeasures to states and communities in a disaster,” Dr. Lisa Kaplowitz, an HHS preparedness official, said in an email.

Homeland Security, established in the aftermath of 9/11, is still working out organizational kinks, according to officials. Fetcher said coordination efforts with HHS are underway and have been since the department was created in 2003.

“We have and will continue to closely coordinate our products with HHS, and we anticipate even greater harmonization on these efforts with the development and completion of formal procedures for CBRN risk and threat assessment production in the coming year,” Fetcher said.