DOT tankers without their motive power may be PSM covered processes

A few years ago we were asked to participate in an engineering review/facility siting for a proposed facility.  The business was in a $ crunch so one way they decided to save some $ was to utilize DOT-306 tankers as “temporary storage tanks”, thus reducing the number of above-ground storage tanks AND a reduction in the size of secondary containment.  As we got into this review, we noticed they had a “Concrete Pad w/ Containment” against the fence line in the “back 40”.  This pad was where they planned to stage their “dropped” flammable liquid tankers.  Once we explained the drawbacks to this plan and all of the baseline regulatory requirements for their plan – they were not happy campers.  Here is why this is not a great idea – it can be done, but these are the impacts:

1. DOT-306 tankers are NOT atmospheric tanks – they actually have relief devices around 3 psi and these tankers will hold around 7-8,000 gallons or 50,000 pounds dependent on the flammable liquid(s) inside them.  So these tankers, without their motive power, are a PSM-covered process.  Source:  https://www.osha.gov/laws-regs/standardinterpretations/1994-07-11
2. NFPA 30, Table 22.4.1.1(b) states that these dropped tankers will need to be at least 50′ from the property line
3. The area will need fire protection, above basic fire extinguishers
4. This area is for STORAGE ONLY – no transfers take place in storage areas!  So the facility will need the ability to move the trailer to a DESIGNED UNLOADING station, which comes with its own design and facility sitting requirements.

As I said in my article (Unloading HAZMATs with video monitoring and PSM/RMP)

All of the DOT requirements apply ONLY when the tanker is still attached to the tractor (i.e. motive power). We are splitting hairs here, but DOT has made it clear that when the trailer is “dropped” and is standing alone without a tractor attached then the HMR does not apply.

But before we get too excited because the HMR does not apply to “dropped trailers” we need to understand what rules could apply.

A tanker of Toluene will carry around 50,000 pounds of the flammable liquid; this means it exceeds the PSM threshold of 10,000 pounds of flammable liquids.

So does this mean the dropped trailer is a PSM-covered process? After all, the DOT tankers are NOT atmospheric storage tanks; in fact, the MC-306 tanker, which is the one that carries most flammable liquids, has a maximum operating pressure of up to 3 psi.  So a “dropped trailer” that has over 10,000 pounds of a flammable liquid with a flashpoint below 100°F (37.8°C) on-site in one location, in a quantity of 10,000 pounds (4535.9 kg) or more is in fact a PSM covered process. So the loading or unloading of this flammable liquid would fall under the PSM standard, which would require PSI, PHA, SOPs, and Training for the operation.

We can see this from a 1994 OSHA LOI regarding tanker trucks and railcars…  (Source: https://www.osha.gov/laws-regs/standardinterpretations/1994-07-11)

Lastly, I want to make this perfectly clear to those who want to know…

One thing to note is that many years after Schneider LOI was published, in 2003 DOT promulgated 49 CFR 171.1, Applicability of Hazardous Materials Regulations (HMR) to persons and functions.

This DOT regulation states:  (emphasis by me)

In other words, since 2003 DOT stated we do not cover the HAZMAT in those situations above AND thus gave this subject jurisdiction to OSHA/EPA. No more 4(b)(1) for these situations!