Can you take Vaseline on a plane?

On a domestic flight the 100ml liquid limit does not apply. On an international flight it does.

Domestic flights in Japan

The 100ml liquid limit does not apply.

International flights from Japan

Each container 100ml or less, all of them inside one transparent re-sealable bag of 1 litre or less, one bag per person.

The list does not name petroleum jelly. The answer follows from its definition of a liquid and from the ointment entry.

No list quoted on this page uses the word Vaseline, so each authority's description of a gel or paste does the work.

The nearest named items in Japan are ointment and first-aid salve

The Japanese version of the creams row starts with 軟膏 (ointment) and 救急用塗り薬 (first-aid salve) and runs on to moisturising cream. The row therefore covers a skin product whether it is sold as a remedy or as a moisturiser, which are the ways a jar of petroleum jelly is labelled.

Airlines in Japan describe it as a paste or semi-solid

ANA's FAQ on liquids for international flights gives pastes such as toothpaste and semi-solids (半固形物) as examples of what counts. JAL's notice says liquids include gel-like items, and that 1 millilitre is read as 1 gram, which is the unit on a jar sold by weight.

If the jar is carried as a medicine

Japan's list has an exception for prescription and over-the-counter medications in liquid or gel form: no container size, only the amount necessary in the cabin, and a declaration to the screener. The list does not say whether petroleum jelly counts as a medication. Its own skin example, ointment, appears in the Creams, Lotions row on the restricted side.

Bringing it into Japan

Entry rules come from the health ministry and are separate from the cabin rules. Its page for travellers sets the same figure on both possible readings of a jar: cosmetics up to 24 per item, and drugs for external use, a group the Japanese page explains with ointments for the skin, also up to 24 per item. Petroleum jelly is not named in either line.

The carry-on answer for petroleum jelly is the same in all 6 other places we checked. The limits themselves are not identical, so read the row for the country you fly from.

Each row comes from that authority's own page. Airlines can be stricter, and the screening officer has the final say.

What to do

Move petroleum jelly to the bag you check in before you reach security, within the checked-baggage limits above. Narita Airport states that anything given up at the checkpoint is discarded and cannot be returned.