So much media coverage of the explosion in Northwest Houston on January 24, 2020. It is assumed that the explosion was caused by a propylene leak, a flammable gas that most people had never heard of before the explosion. What is so sad is that some politicians are jumping on board this tragedy and calling for OSHA and EPA to answer why this facility was not a PSM and RMP facility. Two of the more prominent politicians who are screaming for OSHA/EPA answers were around in 1992 when OSHA promulgated the PSM standard and the exemptions in the standard. It is quite simple as to why OSHA never did a PSM inspection at this facility…
The propylene assumed to be around 14,500 pounds in the process if the 2,000-gallon storage tank was filled to the 85% mark. This clearly would have exceeded the 10,000-pound threshold for a Cat 1 Flammable Gases to be a covered Highly Hazardous Chemical. But there is one wrinkle in this plan…
1910.119(a)(1)(ii)(A) Hydrocarbon fuels used solely for workplace consumption as a fuel (e.g., propane used for comfort heating, gasoline for vehicle refueling), if such fuels are not a part of a process containing another highly hazardous chemical covered by this standard;
From all accounts in the media and the company’s website, the propylene was being used solely as a fuel, thus it would have been exempted under the current standard.
But in the matter of EPA, Propylene (Cas # 115-07-1) is one of the sixty-three (63) flammables covered by the Risk Management Plan (RMP) rule and it has a threshold of 10,000 pounds.
The RMP rule does NOT have the fuel exemption, except when the fuel is “Held for Sale as Fuel at Retail Facilities.” (ยง68.126) This would apply to Propane retail facilities, not a facility like the one that exploded. So EPA may have some answering to do; but if the facility NEVER submitted an RMP, how was EPA supposed to know they had that much propylene.
This takes us back full circle to the EPCRA/Tier II reporting. Was the facility compliant with this reporting requirement? Did the LEPC know? Did the Houston FD know? Did 14,000 pounds of a flammable gas fall UNDER the radar in a town like Houston where facilities have hundreds of thousands of pounds of flammables?
We will have to wait and see, but for now, know this – the process would most likely have been exempted from OSHA’s PSM because of how it was assumed to be used; however, the facility appears to have needed to submit a Risk Management Plan (RMP) for this Propylene.