This has been a fun week with all the dialogue I have had with so many SAFTENG members; I only wish more were comfortable having these discussions online, but the fear of being traced back to an employer or being trolled by a lawyer I guess is a legitimate fear in our technical/risk profession. One of the most popular responses I have received is “why does it matter if the chemical has an NFPA 4 or 2… its a CAT 1 Flammable Gas and thus it is a PSM chemical… let them put what they want in the diamond – it matters not what the diamond says”. But it DOES MATTER what the NFPA 704 diamond says and here is a perfect example of why…
One client who has this CAT 1 Flammable Gas on-site has decided that their process was indeed a PSM covered process. So the management at the facility made the decision to reduce the inventory of the material so that they are well under the 10,000 pounds TQ. The safety manager was elated but was also quick to inform the engineering and operational management that this CAT 1 Flammable Gas still deserves respect and attention. This safety manager was one of those who was quick to correct the NFPA 704 Diamond on his tank from a “1” to a “4” – albeit not at the appreciation of his management group. Because the state where they are located has a State Fire Code based on the 2012 International Fire Code, the safety manager has a platform to use to ensure the process handling this CAT 1 Flammable gas has some minimum safety design(s). So what does this mean?
We have to remember, there is NO OSHA “FLAMMABLE GAS” standard that a safety professional can turn to when needing some guidance on what the minimum safety requirements are. Sure they can try and use 1910.102, .103, .110, etc. but those are specific to their flammable gas and we all know how some managers are quick to point out “proper application” of the standards. So this safety manager knew the IFC had some decent baseline design requirements that were applicable to his process handling this CAT 1 Flammable Gas… only one problem – his engineering manager was quick to point out that the SDS for this chemical says the NFPA Flammability Rating is a “2” – not a “4”, even though the SDS revision before says its a “4”. “The manufacturer knows best what the NFPA rating should be” he is told. This all matters because he wanted to use the IFC to drive good engineering practices for this material and the IFC uses the NFPA 704 “Degrees of Hazards” when establishing the requirements for Design and Construction of systems handling Hazardous Materials. The IFC specifically calls out Flammable and Health Degree of Hazards of “3” and “4” such that they REQUIRE additional design and construction specifications due to the increased hazards of these hazardous materials. Here is what the IFC 2015, Chapter 50 HAZARDOUS MATERIALS—GENERAL PROVISIONS says about this:
Where gases or liquids having a hazard ranking of:
Health Class 3 or 4
Flammability Class 4
Instability Class 3 or 4
in accordance with NFPA 704 are carried in pressurized piping above 15 pounds per square inch gauge (psig) (103 kPa)…
and
Supply piping and tubing for gases and liquids having a health-hazard ranking of 3 or 4 in accordance with NFPA 704 shall be in accordance with ASME B31.3…
Here is the full explanation of why the correct NFPA Diamond Degree of Hazard(s) matters…