A small unmanned aircraft may not carry hazardous material. Section 107.36 states that prohibition in one sentence, and it says the term hazardous material is defined in 49 CFR 171.8. Nothing in §107.36 creates an exception for a package under 1 pound, for flight over private property, for a customer who agrees to the carriage, or for an aircraft that is broadcasting Remote ID. A lithium battery installed to power the aircraft is not that cargo question. Treat a damaged flight battery as an airworthiness problem.
The carriage rule, and what it does not soften
Section 107.36 applies to the operation of a small unmanned aircraft while it is carrying hazardous material. The cross-reference does the defining. If you need the legal meaning of the term, read 49 CFR 171.8 rather than guessing from a product label or from a list this regulation does not contain. Part 107 does not name household items, and this page will not promote an unnamed product into that category.
The knowledge-test item is built to catch invented exceptions. "Allowed if the material is under 1 pound" is not in the section. "Allowed over private property" is not in the section. Remote ID compliance does not rewrite it either. If the material meets the 49 CFR 171.8 definition, the small unmanned aircraft may not carry it.
Dropping an ordinary object is a different sentence, §107.23(b), explained on the dropping objects page. A safe drop zone does not authorize hazardous-material carriage. A ban on hazardous-material carriage does not turn every release of a non-hazardous object into a violation.
The flight battery is an aircraft-condition question
The battery questions paired with this topic ask about a swollen lithium battery and about thermal runaway. Their explanations treat those facts as safety of the aircraft, not as a finding that the installed power battery is hazardous material under §107.36. Keep the two questions apart unless an explanation explicitly joins them.
Section 107.15 says no person may operate a civil small unmanned aircraft system unless it is in a condition for safe operation. Before each flight, the remote pilot in command must check the system to determine whether it is in that condition. No person may continue a flight when he or she knows, or has reason to know, that the system is no longer in a condition for safe operation. A battery that is visibly failing is a reason to know. How that preflight judgment works is on the condition for safe operation page.
Swollen packs and thermal runaway
A lithium battery that is visibly swollen comes out of service. Do not fly it. Do not charge it. Puncturing it to relieve pressure is the wrong action. Flying it once more and then discarding it is the wrong action. The safe step is to stop using that pack.
Thermal runaway means a self-sustaining chemical reaction that can cause a fire. It is not the name for ordinary fast charging. It is not a battery that is cooling too quickly. A swollen case is a visible warning that the pack is not fit to power a flight. Installing it for a short job because the site is close does not restore a condition for safe operation.
Maintenance of a small UAS under Part 107 can be done by the owner or operator following the manufacturer's instructions. That does not authorize flying a damaged battery while you wait for a shop. If the pack cannot be returned to a safe condition, it does not go on the aircraft. Record habits for repairs and inspections are discussed with small UAS maintenance.
How the two rules show up on a test item
Read the stem before you pick a section. If the question is about operating a small unmanned aircraft while carrying hazardous material, the answer is the §107.36 prohibition, with the definition living in 49 CFR 171.8, and with no exemption inferred from weight, consent, or Remote ID. If the question is a swollen lithium battery, the answer is to remove it from service and not fly or charge it. If the question asks what thermal runaway is, the answer is a self-sustaining chemical reaction that can cause a fire.
A pilot who calls every flight battery "hazardous cargo" has mixed the items. A pilot who flies a swollen pack because §107.36 "only applies to packages" has missed §107.15. Use the section the question is actually testing.
Work the carriage item and the battery items in the free practice test. The lessons that separate these rules are in the course at pricing.