As far as licencing goes, you can transport up to 1000 lbs. of certain hazmat classes without requiring a hazmat endorsement, so the one propane tank is legal - look at how many RVers have them on the back of their RVs. If you're operating as a third party carrier, it does get a little more complicated, however. If that tank is attached to the forklift as you transport it, it's considered part of the vehicle. However, if the tank is placed separately from a unit it's being transported with, then it requires the carrier to have hazmat insurance (whether or not the load requires a hazmat endorsement).
Due to a recent traffic stop with the state police, I now know that the maximum you can carry without having a hazmat endoresement is 119 gallons. For reference, the large 100lb propane tanks hold approx 24 gallons. You are fine hauling several of the smaller forklift tanks. Just make sure they are properly secured.
how much propane can you haul without hazmat endorsement
If you don't have a hazmat endorsement, up to 1,000 lbs.
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Some gas companies have fillup stations where you can take your propane tank to have refilled with the assistance of an attendant. However, there may be a restriction as to how large of a tank you can transport legally (hazmat).
An endorsement permitting the driver to transport hazardous materials.
You can. There's a provision in the hazmat regulations that allows you to carry a small amount of hazardous material necessary for the operation of the truck without filling out a hazmat bill of lading for it. I wouldn't carry the cylinder in your sidebox, though; if it leaks the propane will go right into your cab. (You would need to provide a box for the cylinder. You are not actually allowed to carry ANYTHING on your catwalk per DOT regulation.)
A felon cannot get a hazmat endorsement anywhere in the US. This is a federal matter, and does not vary between states. Beginning in 2005, a TSA background check and fingerprinting became required for a hazmat endorsement. This was in response to both the September 11th attacks and the theft of two propane tankers (later recovered) in Texas which were feared to have been stolen for the purpose of a terrorist attack (although someone who'll steal a propane tanker isn't likely to care about having an endorsement or not).
Up to 1000 lbs. before a CDL and hazmat endorsement is required.
If the GVWR is 26,000 lbs. or less and it's not a: carrying a quantity of hazmat which requires placards to be displayed or b: a bus designed to transport more than 15 people (including the driver), yes.
Yes, UPS will transport regulated hazardous materials overseas, but only if you have a contract with them that includes carrying hazardous materials. Various materials are classed as HAZMAT for different reasons. UPS and FedEx both transport hazardous materials, but may not transport ALL hazardous materials. Check the tariffs at the UPS site, and contact UPS HAZMAT section for specific requirements for packaging and labeling, as well as customs information.
Yes. You need a CDL and a hazmat endorsement both. You're well above the allotted amount which can be transported without the tanker and hazmat endorsements.