While looking for an SOP on a large metropolitan fire department's website, I stumbled across something unrelated that caught my eye. This SOP was from a fire department I highly respect as leaders in safety and employee health. To my surprise I noticed an SOP allowing for firefighters to remove their SCBA if the carbon monoxide level is less than 50 ppm in the sampling. It is commendable that a fire agency is addressing the exposure of CO and following OSHA's permissible exposure limit of 50 parts per million over an 8-hour time frame. Operational SOPs really need to look at the science and at the long-term and chronic exposure issues involving CO. There has been excellent work done to identify the risk associated with CO from a knock down or acute illness standpoint. Yet some of the finer details are often missed in the attempt to get the message across. This is due to a lack of surveillance on exposures and patient outcomes by federal agencies. It's especially true when it comes to firefighters, as only a handful of NIOSH and NIST investigators really understand the fire service's challenges with exposures to chemicals and suppression activities. Many of these findings don't make it into rehab policies. Therefore, the two insidious effects of exposure to carbon monoxide often go unrecognized in the fire service.