"Throughout the first 5 parts of this series, we have considered the risks of exposure to diesel exhaust, management of personnel exposures, the spread of diesel exhaust through the fire station, and strategies for mitigation.
In Part 6, we will consider air testing, appropriately documented, which is ultimately how we verify employee safety when there is an airborne hazard.
Although diesel exhaust has an odor and may be irritating to some people at higher exposure levels, your sense of smell is not an accurate method for determining the concentration of diesel exhaust components to which personnel may be exposed. Yes, you may be able to say that there is some diesel exhaust in the area, but you cannot say with any reliability that it is present at either a safe or a hazardous level.
In truth, it is challenging to answer this question even with air testing. One of the reasons for this was discussed in Part 1 of this series. Diesel exhaust is not a simple workplace air contaminant but is a complex composition of dozens of compounds including both gases and particles.
Often people do not realize that there is no test method, Occupational Safety and Health Act (OSHA) Permissible Exposure Limit (PEL), or other reference exposure level for diesel exhaust as a whole. (Unfortunately, we don’t yet have a Star Trek tricorder that will tell us how much diesel exhaust we have and whether it is dangerous to life or health!) We must consider the individual components.
On its Chemical Sampling Information page for Diesel Exhaust, OSHA states that it has no sampling method for diesel exhaust, but instead recommends sampling for several of its components: acrolein, benzene, carbon dioxide, carbon monoxide, formaldehyde, nitrogen dioxide, and sulfur dioxide. For each of these, there is a method of sampling and analysis available from OSHA or the National Institute of Occupational Safety and Health (NIOSH). There is also an OSHA PEL for each of these compounds, so that interpretation of results can be relatively straightforward and meaningful.
In addition, OSHA refers the reader to NIOSH Method 5040, for measuring diesel particulate matter (DPM) as total carbon (with both organic carbon and elemental carbon reported by this method)."
-Featured on Firehouse Magazine