Most hazmat responders know the importance of environmental sampling at emergencies; not only does it make sense to sample for flammability, oxygen content, and toxicity for safety reasons it is mandated by the OSHA Hazwoper law [29 CFR 1910.120(q)]. Data interpretation is also another important reason to sample, as data attained from complete and effective sampling can greatly aid responders in risk assessment, strategy and tactics, and tell responders when to turn the scene over to responsible parties. Yet how many hazmat response teams have a clear and concise system for environmental sampling at every emergency? Every hazmat team can enhance their safety and efficiency by establishing well-thought-out environmental sampling guidelines.
Photo By David F. Peterson
Our team recognized the importance of consistently applying environmental sampling procedures at every hazardous material incident. This realization came after several years of being inconsistent whereby many responses utilized poor choices of monitors or in some cases no sampling efforts whatsoever. Inconsistencies were magnified shift to shift as we were all over the board with our sampling procedures. While there were no close calls (as far as we know), hindsight revealed that we were in need of some improvement, not just to be safe but also to be compliant with hazmat response regulations.
We knew what we had to do. We went to seminars and courses, we made phone calls to monitoring instrument manufacturers, and we discussed safety guidelines concerning our sampling procedures among ourselves. As a result of these efforts, we devised guidelines that will be used at each incident along with appropriate personal protective equipment. Multiple entries may be required to complete the procedure. They are as follows:
Environmental Sampling Procedure
- Step #1 - Check atmosphere for pH using both wet and dry paper.
- Step #2 - Check atmosphere for LEL and oxygen level simultaneously and with each of the following steps. Also, check for radiation on Step #2.
- Step #3 - Check toxic levels with available instrument(s).
- Step #4 - Check atmosphere with colorimetric tube(s) for known or unknown material(s).
- Step #5 - Use PID if CGI does not register to look for smaller concentrations.
- Step #6 - Use APD 2000 or SAW Minicad if nerve, mustard agents, tear gas, or pepper spray are suspected. Consider using nerve agent/blister agent monitors on Step #2, depending on circumstances.
- Step #7 - Use Miran SapphIRe, SensIR, HazMat ID, HazCat System, Chemical Classifier Strips, or other instrument(s) as needed.
Reasoning and Justifications
Step #1 - Many monitoring instruments use sensors that can be easily damaged by highly corrosive or caustic environments, especially by enduring chronic exposures. Manufacturers have stated that corrosive environments that cannot be endured by unprotected humans can also damage sensors. Since sensors are expensive, it behooves responders to avoid environments that significantly shorten their lives. Our guidelines simply use wet and dry pH paper upon initial entry. If either paper indicates dark red (acidic) or dark blue (caustic) environments, we may immediately exit and rethink subsequent entries with expensive instruments. Quantitatively, environments below pH of 3 or above pH of 11 should be reported to team officials in the cold zone. An alternative response to extreme pH environments may be to ventilate the area remotely. If there is no change in the pH paper, proceed to the next step. (Other colorimetric paper such as the Chemical Classifier Strips may also be used on Step #1).