I hope everyone has a very Happy Holiday period with friends and family!
I have had a couple of discussions of late concerning hazardous sampling locations and there seems to be quite a bit of confusion over what that would include and what documentation there has been concerning the requirements.
The major documentation I have seen is that which is included in the method under section 6.1.1 which states:
NOTE: If it is not possible to use a heating system for safety reasons, an unheated system with an in-stack filter is a suitable alternative.
In my opinion, and in concurrence with various regulatory entities regarding discussions on the matter, this only applies to situations where flammable gases would require the use of intrinsically safe equipment to limit the possibility of fire or explosion. In my experience to date, there have been few sources outside of the petrochemical, natural gas, or landfill operations which have possibly met this requirement. The recent discussions about the use have all been in facilities where there was no flammability issue documented as the basis for being a hazardous location.
I have not seen nor have I been able to confirm the existence of any of the letters, notices, guidance documents, or the like which have been said to indicate a less strict definition of what would be considered hazardous than the caveat in the method.
The belief I have encountered is that merely stating there is a hazard thereby makes it a fact and the regulatory agency would then have to show there was no hazard. This seems to have a fatal flaw in the logic as the intended new application of the term would be to remove all hazard, which is not possible. Testing is somewhat hazardous even with the in-stack filter and not significantly more so with the heated probe and filter.
One of the recent discussions finally ended when the agency agreed to abide by the determination of a state safety inspection of the facility to determine the hazard level of the facility test site. It seems the source did not want to be classified as a hazardous location for their workers and the issue was dropped.
As a result, I would recommend that attempts to replace the heated probe and filter be tied to some identified condition, the removal of which would have a significant impact in reducing risk of injury or death. A more frivolous or confrontational approach would seem to be counter productive in the long run.
Triangle Environmental Services, Inc.
P.O. Box 13294 122 US Hwy 70 E
Research Triangle Park, NC 27709 Hillsborough, NC 27278
(919) 361-2890 (800) 367-4862 Fax: (919) 361-3474