The short version
- Stock in this order: binding rule, scale, contents, US layer, cargo items, record. Reversing the order is what produces a full chest that still fails.
- The binding instrument is your flag state’s medical scale under MLC 2006 Standard A4.1. The WHO guide is guidance, not law.
- Quantities come from the WHO Quantification Addendum, 2010, scaled to persons aboard and days from a full-service port.
- The US adds a layer no international stocking list covers: FDA CPG 460.500 for prescription supply and 21 CFR 1301.25 for controlled substances.
- Inspection interval is not more than 12 months, and the dated signed record is the document that settles the question.
A chest can hold every medicine on the WHO list and still be wrong. The list is step three of six, and operators who start there tend to buy the right drugs in the wrong quantities under the wrong legal authority.
This page walks the six steps in the order a chest is actually built, marks the two places US rules diverge from the international picture, and names the document each step produces. For the work done for you, see MedChest management.
Before anything else: check the age of your sourceThe Ships’ Medicine Chests Recommendation, 1958 (No. 105) still ranks on page one of Google for chest contents queries. The International Labour Conference withdrew it at its 111th Session in 2023[8]. It is a historical document. The live framework is MLC 2006 Standard A4.1 plus your flag state’s own notice.
The build order, and what goes wrong at each step
Each row names the input you need, the document that settles it, and the failure this step produces when it is skipped.
| Step | Input you need | Source of truth | What goes wrong |
|---|---|---|---|
| 1. Establish the binding rule | Flag state, vessel type, trading area | Flag medical notice, then MLC 2006 A4.1 | Building to a generic kit list the flag never accepted |
| 2. Set the scale | Persons aboard, days from a full-service port | WHO IMGS Quantification Addendum | Quantities copied from a sister vessel with a different crew size |
| 3. Select the contents | The scale from step 2 | WHO IMGS 3rd edition, ship’s medicine chest section | Brand names instead of active ingredients |
| 4. Clear the US layer | US port calls, US ownership, controlled drugs | 21 CFR 1301.25 and FDA CPG 460.500 | Treating a Schedule II drug as ordinary chest stock |
| 5. Add cargo-specific items | Dangerous goods manifest | IMO IMDG Code and the MFAG | Kit matched to usual cargo, not the cargo aboard |
| 6. Record and re-check | The completed chest | MLC 2006 Guideline B4.1.1, 12-month interval | A correct chest with no dated, signed inspection record |
Step 1: find the rule that actually binds you
MLC 2006 Standard A4.1(4)(a) requires a medicine chest, medical equipment and a medical guide aboard, inspected at regular intervals[1]. That is a floor, not a list. The contents themselves are set by the flag state.
This is why two vessels in one fleet can carry different chests. A Marshall Islands vessel works to MN 7-042-1[2]; an EU-flagged vessel works to the Category A, B or C scale in Directive 92/29/EEC[9]; a US commercial fishing vessel also answers to 46 CFR 28.210[10].
Do not stock from a supplier’s catalogue category until you have the flag notice in front of you. Five frameworks are set out side by side in our flag-state comparison.
| Instrument | Status, August 2026 | What it governs |
|---|---|---|
| MLC 2006, Standard A4.1 and Guideline B4.1.1 | In force | The binding floor: chest, equipment, medical guide, 12-month inspection |
| ILO Recommendation No. 105, 1958 | WITHDRAWN, ILC 111th Session, 2023 | Historic. Still ranks on page one of Google for chest contents |
| WHO IMGS, 3rd edition, 2007 | Current guidance, not law | The contents reference most flags point to |
| WHO Quantification Addendum, 2010 | Current guidance, not law | The quantities layer that turns a list into a stock order |
| EU Directive 92/29/EEC | In force in the EU | Category A, B and C chests by vessel class |
| 21 CFR 1301.25 | In force in the US | Controlled substances aboard. A separate legal regime |
| 46 CFR 28.210 | In force in the US | First aid equipment, US commercial fishing vessels |
Step 2: scale to persons aboard and days from care
Two numbers drive every quantity in the chest: how many people are aboard, and how many days the vessel is from a port with full medical facilities. Neither is negotiable and neither is a supplier’s decision.
The WHO Quantification Addendum, published in 2010 for the third edition of the guide, exists specifically to convert those two numbers into quantities, indications and dosing[4]. The main guide tells you what to carry. The Addendum tells you how much.
The scaling question to answer firstNot “what does a chest contain”, but “how many treatment days must this chest cover before the patient can reach definitive care”. A 30-day passage with 24 people aboard is a different order from a 3-day coastal run with 12. Copying a sister vessel’s stock order is the most common way this step fails.
Add the voyage pattern, not the voyage average. A vessel that spends most of the year coastal and two months offshore is stocked for the two months.
Step 3: what the WHO guide actually gives you
The International Medical Guide for Ships, third edition, was published by WHO in 2007 as a joint ILO, IMO and WHO text under ISBN 978-92-4-154720-8[3]. Its full title, including the ship’s medicine chest, names the section operators need.
Working with it in practice means three things.
- Use the ship’s medicine chest section as the contents reference, not the clinical chapters, which are for treating rather than buying.
- Pair it with the Addendum. The guide without the 2010 quantities produces a list with no order quantities attached[4].
- Order by active ingredient. International non-proprietary names survive a port replacement in a country where your brand does not exist.
Broad categories run across analgesics and antipyretics, anti-infectives, gastrointestinal and cardiovascular medicines, and first aid and surgical consumables. The category list is the easy part. The quantities and the legal authority to hold them are where chests fail.
Step 4: the US layer no stocking list includes
Every international stocking guide stops at the WHO list. For a vessel that calls at US ports, is US-owned or carries controlled drugs, two more authorities apply and neither one appears in a WHO contents table.
| Authority | What it reaches | What it requires | Citation |
|---|---|---|---|
| FDA | Prescription drugs going into the chest | No federal contents list. FDA states it has never recommended a procedure. The duty of reasonable care against diversion sits with the pharmacist or supplying firm | CPG Sec. 460.500, 1980 |
| DEA | Any Schedule II to V drug aboard | A registered medical officer or the master requisition route, a triplicate record of sale, copy 2 held aboard, two annual reports, disposal under part 1317 | 21 CFR 1301.25 |
| USCG | US commercial fishing industry vessels | First aid equipment and training requirements that sit alongside, not instead of, the flag medical scale | 46 CFR 28.210 |
The FDA position is worth reading in full because it is the opposite of what operators expect. Compliance Policy Guide Sec. 460.500, issued in October 1980, states that FDA does not wish to place obstacles in the way of stocking ships’ chests and has never suggested or recommended any particular procedure[5]. The control it does describe sits on the supply side: the pharmacist or firm supplying the drugs should exercise reasonable care that they reach the chest and are not diverted.
Where a well-stocked chest becomes a legal problemThe moment a Schedule II to V drug enters that chest, 21 CFR 1301.25 applies[6]. That means a DEA-registered medical officer employed by the owner or operator, or the master requisition route, a record of sale in triplicate with copy 2 retained aboard the vessel, an annual report on the officer’s registration expiry and a separate master report per calendar year, and disposal only under 21 CFR part 1317[7].
Compare the two compliance routes in our medical officer versus master requisition guide, or read the rule paragraph by paragraph in 21 CFR 1301.25 explained.
Step 5: hazardous cargo rewrites the list
Carrying dangerous goods under the IMO IMDG Code adds specialised antidotes and equipment on top of the ordinary chest, provisioned against the Medical First Aid Guide[11].
The test an inspector applies is the cargo actually aboard, not the cargo the vessel usually carries. A chest built for the normal trade and never revised for a one-off charter is a finding.
Step 6: storage, labelling and the record
Three conditions, then the document.
- Environment. Secure, clean, dry and temperature controlled. Heat is the quiet destroyer of a correctly bought chest.
- Labelling. International non-proprietary names or ATC codes on every container, so a replacement bought in any port matches what the log says was used.
- Expiry management. Replace ahead of the expiry date, not on it. A drug that expires mid-passage was non-compliant the day the vessel sailed.
Then the record. MLC 2006 Guideline B4.1.1 sets inspection at intervals not exceeding 12 months[1], and the dated, signed inventory is what port state control asks for before it opens a single locker. A correct chest with no record reads, to an inspector, exactly like an unchecked one.
Controlled substances carry their own parallel record set that does not merge with the chest inventory. That separation is covered in the recordkeeping guide.
What the WHO guide does not do
Three limits, stated plainly, because no ranking page states them.
- It is not law. It is guidance that flags adopt. An inspector enforces the flag notice, and where the two differ the flag wins.
- It does not grant authority to hold controlled drugs. Listing a drug is not permission to possess it. That authority comes from 21 CFR 1301.25 in the US regime[6].
- It does not adjust for your route. The quantities are a scaling method, not a finished order. Days from definitive care is an input only you hold.
Common questions
How do you stock a ship medicine chest?
Six steps, in order. Establish the binding rule from your flag state under MLC 2006 Standard A4.1, scale quantities to persons aboard and days from a full-service port, select contents from the WHO International Medical Guide for Ships 3rd edition and its Quantification Addendum, clear the US controlled substances layer, add cargo-specific items, then record and re-check within 12 months. Our MedChest service runs all six.
What is the latest edition of the International Medical Guide for Ships?
The third edition, published by WHO in 2007 as a joint ILO, IMO and WHO text, with a separate Quantification Addendum issued in 2010 that carries the recommended quantities[3][4]. There is no fourth edition. Anything advertised as one is a reseller listing, not a WHO publication.
Is the WHO guide legally binding?
No. It is guidance. The binding instrument is your flag state’s medical scale sitting under MLC 2006 Standard A4.1[1]. Most flags point to the WHO guide, which is why it functions as a de facto standard, but an inspector enforces the flag notice. Compare five flags in our flag-state guide.
How many medicines should a ship carry?
There is no single number. Quantities scale with persons aboard and the days a vessel spends away from a port with full medical facilities, which is exactly what the WHO Quantification Addendum is for[4]. A 12-person workboat on a 3-day run and a 24-person vessel on a 30-day passage do not carry the same chest. Ask us to size yours.
Does the US have a required medicine chest list?
Not for prescription drugs generally. FDA Compliance Policy Guide Sec. 460.500 states the agency has never suggested or recommended any particular procedure for stocking ships’ chests, and places the duty of reasonable care against diversion on the pharmacist or supplying firm[5]. Controlled substances are the exception and are governed by 21 CFR 1301.25[6]. See Controlled Substances.
How often must the chest be inspected?
At intervals not exceeding 12 months under MLC 2006 Guideline B4.1.1, and flag notices such as the Marshall Islands MN 7-042-1 restate it[1][2]. The dated, signed record is what an inspector reads first. See what else is checked in our compliance audit guide.
Can we put controlled drugs in the chest with everything else?
Physically they are usually in the same space, legally they are not the same stock. 21 CFR 1301.25 imposes registration, a triplicate record of sale with copy 2 retained aboard, two annual reports on different clocks, and disposal under 21 CFR part 1317[6][7]. Read the recordkeeping guide.
