(Adds Senate committee comments, paragraphs 3-4)
By David Morgan
WASHINGTON, June 20 (Reuters) - A growing anthrax scare at three government laboratories is drawing scrutiny from Congress about whether the U.S. Centers for Disease Control and Prevention (CDC) has the appropriate safety procedures in place to protect federal employees from contamination.
Oversight committees in both the Senate and the House of Representatives are weighing whether the potential exposure of 84 people to one of the deadliest strains of anthrax at CDC facilities in Atlanta could merit formal congressional hearings, aides said.
One of the panels, the Senate Health, Education, Labor and Pensions Committee, is "closely monitoring" the situation and early next week "will make a formal request to CDC Director Tom Frieden for additional follow-up information," said Allison Preiss, a spokeswoman for Democratic Senator Tom Harkin of Iowa, the panel's chairman.
The CDC said it will cede control of the investigation to the U.S. Department of Agriculture "to avoid potential conflicts of interest."
Lawmakers and aides say the breach is only the latest problem involving safety protocols intended to protect agency employees and visitors at a bioterror lab on the CDC campus, known as Building 18.
Two years ago, visitors to the bioterror lab were inadvertently exposed to air from a potentially contaminated facility. On Thursday, CDC disclosed that a bioterror lab sent samples that may have contained live anthrax bacteria to two lower-security facilities, potentially exposing at least 84 people to the deadly pathogen.
"This certainly may rise to the level of a congressional hearing, especially in light of the fact that not too terribly long ago there were other incidents. Although they're unrelated, they both speak to a breakdown in protocol," said Republican Representative Michael Burgess, a physician who sits on a second CDC oversight panel, the House Energy and Commerce Committee.
"It just begs the question, are the proper procedures and protocols in place to protect personnel?" he added. "It doesn't take much of a breach to create a significant problem for a significant number of people."
An aide with Burgess' committee said staff were monitoring the situation closely to determine whether further steps should be taken. In 2012, the panel investigated the air flow problems and other issues and was assured by CDC officials that the problems had been addressed, the aide said.
High-containment laboratories, which conduct research on potential bio-weapon agents, including anthrax and Ebola, have proliferated since the 2001 anthrax attacks in which spores mailed to news media offices and two U.S. senators killed five people and infected 17 others.
The Government Accountability Office (GAO) warned Congress of an increased risk of laboratory accidents last year, saying the labs lack oversight and operate with no national safety standards.
The GAO recommended that the administration make a single federal agency responsible for assessing lab standards, but said in its February 2013 report that the administration rejected the recommendation as "unnecessarily broad and cumbersome." (Reporting by David Morgan, editing by G Crosse, Bernard Orr)