A Transfer Built to Be Repeated
On 17 September 2026, at a shipyard in Kumamoto Prefecture, an ammonia carrier of about 1,000 gross tonnes discharged fuel into a 40,000 cubic metre gas carrier built to burn it. The receiving ship is due in November and will run on ammonia during sea trials. The quantity was not published, and the figure is beside the point: ammonia has crossed between carriers as cargo for decades. What was new was the destination.
The timing was not accidental. The International Maritime Organization held a technical seminar on ammonia the same day, drawing around 800 participants during its carriage of cargoes sub-committee, and Japan's transport ministry had already issued bunkering guidelines in June 2025 covering gas detection, emergency release, controlled areas, training and protective measures.
That changes the buyer's question. Emergency response asks what a crew wears once. Bunkering asks what an operator wears at a manifold, week after week.
The Only Ammonia Letter Is a Diluted One
Chemical gloves sold into Europe are marked under EN ISO 374-1, which tests eighteen reference chemicals and prints a letter for each one passed. Ammonia appears once, as code O: a 25 percent aqueous solution, tested to EN 16523-1 at close to 23 degrees Celsius on flat material samples.
Fuel ammonia is neither. It is anhydrous, held as a liquid near minus 33 degrees Celsius, and flashes to vapour on meeting a warm surface. A glove at performance level 6 against code O has proved something real, but about another substance, in another phase, 56 degrees from the manifold.
None of this makes the marking dishonest, only incomplete, and that gap is where procurement mistakes live. Two gloves compared on the O code alone are compared on the least relevant line of their sheets.
Water Makes Ammonia Worse
The instinct carried over from acid response is to dilute, and with ammonia that needs a second look. Its appetite for water is why it burns: on skin and in the airway, anhydrous ammonia takes moisture and becomes ammonium hydroxide, caustic and staying where it formed.
For gloves the implication is uncomfortable. A sweat-soaked liner is a water reservoir against the hand, so vapour reaching it is held there instead of passing through. A glove can pass a permeation test and still dose the wearer, because the mechanism is absorption rather than breakthrough. A glove wetted with liquid or heavy vapour is retired, not dried and returned to the locker.
Water returns on deck: washdown leaves an alkaline film boots stand in for the rest of the shift, attacking sole adhesion and seams after the transfer ends.
Boots, Cuffs and the Direction of a Suit
Gas-tight ensembles certified to EN 943 close over the boot top for a reason: with a liquid that boils and a vapour seeking the lowest point, an open boot is a reservoir at ankle height. That runs against cryogenic gas practice, where trousers sit outside the boot so liquid runs off. Both fit their hazard, but a crew handling more than one fuel at one terminal needs the difference written into procedure.
Footwear hits a standards gap too. EN 13832-3 covers laboratory resistance to a defined list; it says nothing about a sole stiffening on a cold, wet deck, or about grip on frost.
The most useful evidence a supplier can offer is not another certificate: permeation and degradation results for anhydrous ammonia at the working temperature, a drawing showing how the cuff meets the suit sleeve, and a retirement rule counting couplings rather than calendar days.