Propane Plant Operator 3 (PPO-3): O. Reg. 215/01 scope, cylinder inspection and collar stamps, the 42% / 80% fill limits, filling by weight, trade measurement, storage and transport
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About the certification
In Ontario, propane handling is regulated by the Technical Standards and Safety Authority (TSSA) under O. Reg. 211/01 and O. Reg. 215/01. A Propane Plant Operator 3 (PPO-3) certificate, or a record of training (ROT) for it, lets a person fill containers, including vehicle tanks, and operate propane transfer equipment in a filling plant or container refill centre (O. Reg. 215/01, s. 36).
TSSA does not publish a PPO-3 exam format: training is delivered by TSSA-accredited providers and ends in a record of training. ExamHub's Test Mode therefore draws 30 questions in 60 minutes with a 75% target as practice only; it is a practice length, not the official format.
| Issuer | TSSA (Technical Standards and Safety Authority) |
|---|---|
| Authority | O. Reg. 215/01, s. 36 |
| What it allows | Fill containers, including vehicle tanks, and operate propane transfer equipment at a filling plant or container refill centre |
| Official exam format | Not published: training is delivered by TSSA-accredited providers and ends in a record of training |
| ExamHub practice test | 146 questions; 30-question Test Mode, 60 min, 75% practice target |
ExamHub's free PPO-3 practice test has 146 original questions, each with an explanation and a free public source.
Sources used: O. Reg. 211/01; O. Reg. 215/01; TSSA advisories FS-090-06-R1 and FS-260-22; Measurement Canada Bulletin C-03; Canadian Propane Association.
Sources checked: October 2026. See how ExamHub writes and checks questions.
Studying the 42% / 80% fill rule? Gas piping and pressure-testing basics are in our TSSA Gas Technician 3 (G3) practice test. Propane also fuels many lift trucks, so try the forklift practice test, and review hazard labels and safety data sheets in the WHMIS practice test.
What's covered
Categories cover PPO-3 scope: regulations, propane properties and hazards, cylinder inspection, filling and fill limits, leak testing, storage and transport.
Try a few
Five sample questions from the question bank, with the answer and explanation.
Why: Filling by weight is limited to 42% of the cylinder's water capacity, which is based on a relative density of about 0.51 for propane.
Why: The propane limit is 42% of the water capacity: 0.42 x 22.7 = about 9.5 kg. The scale reads the tare weight plus the propane: 8.2 + 9.5 = about 17.7 kg. A reading of 26.4 kg uses the 80% volume figure by mistake, 30.9 kg adds the whole water capacity to the tare, and 9.5 kg forgets the empty cylinder.
Why: TSSA Advisory FS-090-06-R1 reports OPD valves failing and cylinders being filled to 100%. The OPD is not a gauge; the filler must fill by weight or by volume with the fixed liquid level gauge.
Why: B149.2 clause 6.4.4 (as quoted by Alberta) says a damaged or leaking cylinder, one corroded beyond Transport Canada limits, or one due for re-examination is not filled but removed from service. Industry visual-inspection guidance (US DOT) lists bulges, dents, cuts, cracks, heavy rust or pitting, a missing foot ring, collar or valve cover, and a leaking valve or relief device as reasons not to fill. Dirt, faded paint, several requalification stamps and ordinary manufacturer marks are not defects.
Why: Bulletin C-03, s. 8.2 sets mandatory inspections at every two years for scales used to weigh propane sold in cylinders. Propane meters have different intervals: each year for retail consumer sales and every two years for commercial or industrial sales.
FAQ
No. This is unofficial study practice written from free public sources: Ontario e-Laws (O. Reg. 211/01 and 215/01), TSSA advisories, Transport Canada, Measurement Canada and the Canadian Propane Association. It does not reproduce the licensed CSA B149.2 text or real exam questions.
Test Mode draws 30 questions in 60 minutes with a 75% target. These are practice values: TSSA does not publish a PPO-3 exam format, because training is delivered by TSSA-accredited providers and ends in a record of training (ROT) whose tests differ by provider. It is not the official format.
Under O. Reg. 215/01, s. 36, a PPO-3 holder, or a person with a record of training for it, may fill containers, including vehicle tanks, and operate propane transfer equipment in a filling plant or container refill centre.
Under O. Reg. 215/01, a PPO-3 holder may not drive a propane tank truck or fill containers on an end user's premises (that needs a PTO certificate or record of training, s. 38), and may not examine or requalify cylinders (that needs a PCI certificate or record of training, s. 37).
By weight, to 42% of the water capacity, or by volume, to 80% if the cylinder has a fixed liquid level gauge designed for it. A float gauge, an OPD valve or a dispensing meter must never be used to decide the maximum filling.
No. TSSA Advisory FS-260-22 says the scope of a TSSA certificate or record of training does not cover filling one-pound cylinders, so no one in Ontario may fill them, including certificate and record of training holders. Cylinders can only be filled at TSSA-licensed facilities.
No. These are original practice questions with an explanation and a named source for every answer. They are not copies of exam questions.