When first responders suit up for a possible bioterrorism situation or unknown chemical release, a respirator may be a life-and-death decider. The National Institute for Occupational Safety and Health (NIOSH) revised its recommendations for responders, incorporating two advances made since the previous 2001 guidelines. Respirators should be rated for chemical, biological, radiological and nuclear (CBRN) hazards. In addition, protective clothing should comply with National Fire Protection Association (NFPA) standards. NIOSH emphasizes that the guidelines are oriented toward terrorist incidents and do not apply to controlled use of biological agents in labs. To see the complete recommendations, visit www.cdc.gov/niosh/docs/2009-132/.