Climatic zones by country: WHO's stability conditions for 23 countries in the Gulf, the Levant and Africa, and the zones they correspond to

WHO's list gives conditions, not zone names; the zone is our reading of each condition against the note to Table A10.4 in WHO's TRS 1010, Annex 10. Source: WHO, Stability conditions for WHO Member States by Region, update of March 2021, written for medicines. Square brackets are WHO's mark for an estimate. Country names are shortened (Libya for Libyan Arab Jamahiriya, Tanzania for United Republic of Tanzania). Rows run by region: the Gulf and the Levant, North Africa, West and Central Africa, East Africa, southern Africa. Checked 9 October 2026.

Read against that note, 30 °C/75% RH corresponds to zone IVb, 30 °C/65% RH to zone IVa and 25 °C/60% RH to zone II. Five countries in the table have only an IFPMA estimate, not confirmed by the regulator: Kenya, Ethiopia, Senegal and Côte d'Ivoire at 30 °C/65% RH, Algeria at 25 °C/60% RH. For packaging, the condition is the heat and humidity a stability study holds the product at; how much of that humidity gets to the product depends on its pack.

What do climatic zones II, IVa and IVb mean?

Each zone stands for a long-term storage condition: the temperature and relative humidity (RH) at which a product is kept and tested over the shelf life claimed for it.

WHO's guideline on stability testing (Technical Report Series No. 1010, Annex 10, 2018) chooses the long-term condition by the climatic zone of the market where the product will be sold. Its note to Table A10.4 states the condition for three zones:

• Zone II: 25 °C/60% RH.
• Zone IVa: 30 °C/65% RH.
• Zone IVb: 30 °C/75% RH, the most humid of WHO's three long-term conditions.

During a study the temperature is held within ±2 °C and the humidity within ±5% RH. Accelerated testing, which shows early how a product reacts to stress, runs at 40 °C/75% RH for six months.

In the WHO texts we read, the long-term condition is stated by name for zones II, IVa and IVb only; zones I and III are mentioned without a condition of their own. This page covers the three zones whose conditions appear for these 23 countries. WHO warns that running stability studies at the conditions of zones I and II for products supplied to zones III and IV "could potentially lead to substandard products".

ICH Q1A(R2), the stability guideline of the International Council for Harmonisation in force on 9 October 2026, addresses climatic zones I and II. Its long-term and intermediate conditions include 30 °C/65% RH, the condition WHO gives for zone IVa. ICH left the conditions for zones III and IV to the regions and to WHO, and in a note quoted by WHO its regulators agreed that data at 30 °C/75% RH are acceptable if an applicant chooses to use them.

Which zone is my market in, and how firm is the answer?

Find the country in the table above: WHO's list gives its long-term condition, and that condition corresponds to a zone. How firm the answer is depends on where WHO took the line from, and the list marks three sources:

• Confirmed (bold type in WHO's list): obtained through regional harmonisation groups, such as the GCC, or from official communications by national medicines regulators to WHO. On this page that covers the six GCC states, Jordan, Lebanon, Egypt, Libya, Tunisia, Morocco, Uganda and South Africa, 14 countries in all.
• Reported in 2008 (normal type): collected from representatives of national regulators at the 13th International Conference of Drug Regulatory Authorities (ICDRA), held in Berne from 16 to 18 September 2008. On this page: Nigeria, Ghana, Cameroon and Tanzania. These lines are 18 years old, and a regulator may have changed its condition since.
• Estimated (italic type in square brackets): provided by the International Federation of Pharmaceutical Manufacturers and Associations (IFPMA) from published climate references, among them a world map of the Köppen-Geiger climate classification. On this page: Algeria, Côte d'Ivoire, Senegal, Kenya and Ethiopia. An estimate is not a statement by the regulator.

Two readings to avoid. WHO's list does not give the GCC states the zone IVb condition: Saudi Arabia, the UAE, Qatar, Kuwait, Oman and Bahrain all have 30 °C/65% RH, which corresponds to zone IVa. And Africa is not one zone: the 15 African countries on this page fall under all three conditions, and only Nigeria, Ghana, Cameroon and Tanzania among them have 30 °C/75% RH.

The main markets of the manufacturing group behind HYPERPHARM sit under two conditions: the UAE and Saudi Arabia at 30 °C/65% RH, Lebanon at 25 °C/60% RH.

The list on who.int is the update of March 2021, and WHO's 2018 guideline calls it a living document. A search on 9 October 2026 found no newer version; that does not prove none exists.

Does WHO's list apply to food supplements?

Not as law: it was written for medicines. WHO's guideline describes it as the list of Member States that have told WHO which long-term stability testing conditions they require when a marketing authorisation is requested, that is, when a medicine is registered.

For a supplement, the rules come from the regulator in the country of sale and from what your importer has to file. Ghana's guideline for supplements carries WHO's zone IVb terms; Saudi Arabia's food guide asks for a stability study without naming a condition in the parts we read. Read the list as the starting point, then confirm with your importer what the regulator asks for.

Where does a regulator name the climate for supplements?

Among the regulators' documents we read, Ghana's names a zone for supplements, Egypt's names one for pharmaceutical products, and Saudi Arabia's food guide names no condition but asks about the packaging material for some tablet and capsule products.

• Ghana. The Food and Drugs Authority's guideline for registering food, nutritional and dietary supplements, issued in March 2013, asks for stability reports under WHO zone IVb conditions. It names accelerated testing at 40 °C ± 2 °C and 75% RH ± 5% for six months and long-term testing until the end of the shelf life, in the container closure system in which the product will be marketed in Ghana. Ask your importer whether the 2013 version is still the one in force.
• Egypt. The Egyptian Drug Authority's stability guideline (GL.CAPP.018, version 4, November 2022) states that "Egypt is categorized in climatic zone IVa", the same 30 °C/65% RH that WHO's list gives Egypt. It is written for pharmaceutical products, and we have not confirmed that it applies to supplements.
• Saudi Arabia. The SFDA's guide for food products (July 2024) asks for a stability study based on the shelf life the manufacturer proposes. For tablet and capsule products sensitive to heat, humidity or sunlight, it asks for a document that describes the packaging material and verifies its safety for use. In the parts we read, it names no testing temperature or humidity.

In the documents we read from the regulators of the UAE and Nigeria, we found no zone named for supplements. For the other countries on this page we have not checked the regulators' own supplement rules; WHO's list and your importer are the starting points there.

Filing the product in the importing country is the brand owner's or the local importer's step, not ours. What we supply for that file is the Certificate of Analysis and the product specification with each batch, and copies of the plant's certificates on request.

What does the zone mean for packaging my supplement?

The zone sets the heat and humidity a stability study puts the product through; the pack decides how much of that humidity reaches the product.

The data follow the pack. Ghana's FDA asks for the supplement stability study to be run in the container closure system in which the product will be marketed in Ghana. If you plan to change the pack, ask your importer what the regulator then expects.

Impermeable containers take humidity out of the study. WHO's guideline lists aluminium/aluminium blisters for solid dosage forms among impermeable containers, which give a permanent barrier to the passage of moisture. For products in such containers, WHO says sensitivity to moisture is not a concern, and the study can run at any controlled or ambient humidity. WHO also notes that zone IVa conditions may be acceptable in place of IVb when humidity is not an issue, for example for storage in glass containers.

A blister seals dose by dose. Each tablet or capsule sits in its own cavity under the lidding foil until it is pressed out, so taking one dose leaves the rest sealed. How much moisture passes into a cavity depends on the film; the films the machine can run are listed on the blister packing page.

A blister is not automatically the stronger pack. A 2017 modelling study of one moisture-sensitive multivitamin tablet, with 100 mg of thiamine, estimated a longer shelf life at 30 °C/75% RH for a 60 cc bottle of 30 tablets with silica gel desiccant than for an aluminium/aluminium blister. It is a calculation for one product, published in a trade journal, and the article features a desiccant supplier's product. It still makes the point that the formula and the pack are chosen together.

The label does not replace the pack. WHO's guideline says a storage statement "should not be used to compensate for inadequate or inferior packaging".

Tablets and capsules are sealed into blisters on an Uhlmann B 1240 and cartoned on an IMA IC 150.

The pack for hot markets is covered on blister packaging for hot and humid markets, and storage, shipping and remaining shelf life on shelf life and storage.

What your product decides

Before you choose a pack or a plant, your formula, your markets and your sales channel settle part of the answer. Each line shows what it costs in time or in risk.

Questions buyers ask about climatic zones

Read more

Blister packaging for hot and humid markets · Shelf life and storage