ISO 18602 is the international standard for proving packaging has been cut back as far as it can go without failing at its job. Spotting a box that is bigger than it needs to be is easy. Proving where the real limit sits is the part that needs a method.
In its 2013 edition, ISO 18602 is that method, the optimization step in the ISO 18600 packaging and environment series.
Optimization does not mean using as little material as possible. ISO 18602 says plainly that swapping to a lighter material is not optimization at all, and that the right answer is sometimes more packaging rather than less.
The short version of ISO 18602
Here is the standard's own identity, as published in the ISO catalogue.
| Detail | ISO 18602 |
|---|---|
| Full title | Packaging and the environment, optimization of the packaging system |
| Current edition | First edition, published 15 January 2013 |
| Status | Published |
| Type | Requirements standard, not a certification |
| Published by | ISO/TC 122 (Packaging), subcommittee SC 4 (Packaging and environment) |
| Family | The ISO 18600 series, applied through the umbrella standard ISO 18601 |
| Covers | Primary, secondary and transport packaging, together as one system |
Optimization means the minimum that still works
Two terms carry this standard. Once those are straight, the requirements are almost obvious.
The minimum adequate weight or volume
ISO 18602 defines packaging optimization as reaching a minimum adequate weight or volume, what the trade calls source reduction.
It looks at the whole packaging system rather than one box. The primary pack, the secondary pack and the transport packaging all count.
The condition attached to that reduction matters as much as the reduction itself. Performance and user or consumer acceptability have to stay unchanged or adequate.
So a bottle that is 15% lighter but arrives cracked has not been optimized. It has just been made worse, and the standard does not let you count it.
Why less is not automatically better
The standard carries a model of the trade-off, and it is the most useful page in the document. Environmental impact does not keep falling as packaging gets lighter. It falls to a low point and then starts climbing again.
Cut too far and goods get damaged or lost, which wastes the product as well as the pack. Go too far the other way and you are shipping material nobody needed, which is plain overpackaging.
ISO 18602 is blunt about which mistake is worse. The environmental cost of product losses caused by cutting too deep is far greater than the cost of carrying a little packaging in hand.
A critical area is what stops you going further
The standard's name for your limit is a critical area, and it defines one as a performance criterion that prevents further reduction of weight or volume without endangering functional performance, safety, or user and consumer acceptability.
In plain terms, a critical area is the reason you cannot take another gram out. Maybe the film has to stay at a certain thickness to survive the filling line. Maybe the tray has to keep its rigidity to be palletised four high.
That is the piece most people miss. ISO 18602 does not ask you to prove your pack is light. It asks you to name the thing that stops it getting lighter.
Swapping to a lighter material is not optimization
The standard draws a hard line here. Substituting one packaging material for another is not a basis for packaging optimization, and packaging design and material selection sit outside the standard altogether.
Its job is narrower and more useful than that. ISO 18602 checks whether the material you have already chosen is being used efficiently, not whether you chose the right material in the first place.
What ISO 18602 requires
The requirements clause is short. It asks a supplier for three determinations, and then for the ability to show its work.
- Identify at least one critical area. Work through the full list of criteria in the standard, the ten set out below, and find the one, or several, that governs the achievable limit for your pack. Finding at least one is what meeting the standard rests on. If you cannot find any, the packaging does not meet ISO 18602 and there is more optimization left to investigate.
- Check for substances hazardous to the environment. Determine whether any substance or mixture classed as an environmental hazard is present and likely to turn up in emissions, ash or leachate if the packaging is incinerated or landfilled. Safety data sheets from your material suppliers are the normal starting point.
- Check for the four named heavy metals. Determine whether lead, cadmium, mercury or hexavalent chromium is present in the packaging component, either by measuring, by calculating from the formulation, or from information your suppliers pass down.
The ten critical areas you work through
The standard lists ten places to look for the constraint that sets your limit. Most packs have more than one.
| Critical area | The kind of limit it sets |
|---|---|
| Protection of goods | Damage, spoilage or contamination in the supply chain |
| Packaging manufacturing process | What the forming, moulding or converting process can actually make |
| Packaging and filling process | Line speeds, closures, headspace, what the filler can run |
| Logistics | Transport, warehousing, handling, stacking and palletising |
| Presentation and marketing of goods | Shelf presence and the demands of how the product is sold |
| User and consumer acceptance | Whether people can open, carry, store and reuse it |
| Information | Room for mandatory labelling, barcodes and instructions |
| Safety | Child resistance, tamper evidence, safe opening, hygiene |
| Legislation | Anything the law requires the pack to be or carry |
| Other issues | Whatever else genuinely constrains your pack |
Safety and legislation are the pair the standard singles out. They are not independent of each other, so it tells you to consider them together rather than one at a time.
How you show the work
None of this counts unless it is written down. On request, the supplier prepares a statement that the three determinations have been made, and keeps the data behind them.
That means documenting the information used to build your list of performance criteria and to establish what the critical ones actually do. It also means using a checklist, or your own equivalent documentation, to show every one of the ten areas was covered rather than the two that were convenient.
Two further duties sit alongside it. Where a hazardous substance is present, you document that minimization was achieved against those same critical areas.
You also confirm that the combined presence of the four heavy metals has been assessed against whatever the local rules require where the packaging will be sold. In the EU that means the four together staying under 100 mg/kg.
Who uses ISO 18602
The standard's own actor is the supplier, which it defines as the entity responsible for placing packaging or packaged goods on the market. That is deliberately broad, because it means any point in the chain where packaging or packaged goods change hands.
In a working week it lands on four desks. Packaging designers and technologists do the actual assessment, because they are the ones who know where the critical areas really are.
Brand owners and fillers place the packaged goods on the market and carry the obligation that comes with that. Converters and importers get asked to supply the evidence for the components they deliver.
Then there are the retailers and buyers, who increasingly want to see the assessment before they list a product at all.
A drinks brand asked by a supermarket to justify a 400 g glass bottle is the everyday case. ISO 18602 turns that awkward conversation into a documented answer instead of an opinion.
ISO 18602 and the EU minimisation rules
ISO calls it optimization. The EU's Packaging and Packaging Waste Regulation calls the same idea minimisation, and from 2030 it stops being voluntary.
What changes on 1 January 2030
From that date, a manufacturer or importer has to make sure the packaging it places on the EU market is designed so its weight and volume are reduced to the minimum needed for the pack to work, allowing for its shape and material.
The regulation also bans packaging built to look bigger than it is. Double walls, false bottoms and unnecessary layers are named outright, and packaging that fails its performance criteria cannot be placed on the market.
Narrow exceptions exist for designs and trademarks that were already protected before February 2025, and for protected geographical indications.
Proof lives in the technical documentation, and it has to name, for every performance criterion, the design requirement that prevents further reduction of weight or volume. Anyone who has run an ISO 18602 assessment will recognise that sentence.
Where the regulation echoes the standard
The overlap is not a coincidence of topic. Three of the regulation's rules track the standard almost phrase for phrase.
- The critical area survives intact. ISO 18602 asks for the criterion that prevents further reduction without endangering functional performance and safety. The regulation asks for the design requirement that prevents further reduction without endangering functionality, including safety and hygiene.
- Material swaps still do not count. The standard says substituting one packaging material for another is not a basis for optimization. The regulation says substitution of one packaging material with another shall not be considered sufficient.
- More material can be the right answer. The standard allows weight or volume to go up to reduce loss of goods. The regulation allows it to go up to allow more trips, more recycled content or better recyclability.
What the standard cannot do for you
Being honest about the limit matters here. The regulation does not name ISO 18602 anywhere, and following the standard does not make packaging compliant.
The harmonised standards that will carry the official calculation method are still being written. The Commission has to ask the European standardisation bodies to prepare or update them by February 2027.
For the most common packaging formats, those standards are expected to set maximum weight and volume limits, wall thickness and maximum empty space.
What ISO 18602 gives you in the meantime is a defensible way to do the assessment now, in the shape the regulation will ask for.
The output belongs in the packaging file behind your EU declaration of conformity, next to the recyclability and recycled-content evidence, which is exactly the kind of record an EPR platform like Repax keeps.
Three standards people mix up with ISO 18602
Optimization sits close to several other standards, and the boundaries are easy to blur.
- EN 13428, the European twin. EN 13428:2004 covers prevention by source reduction and is harmonised under the old EU packaging directive. It runs over remarkably similar ground, including the same four heavy metals and hazardous substances, so ISO 18602 is the international version of that thinking rather than a different subject.
- ISO 18604, the recycling question. ISO 18604 asks whether a pack can be recycled as material. ISO 18602 asks whether it uses more material than it needs. Optimization comes first, and every pack goes through it before anyone looks at a recovery route.
- ISO 18601, the rule-book above it. ISO 18601 decides how and when the series is applied, and ISO 18602 defers to it for that. If you are wondering which standard to reach for and in what order, that is the 18601 question, not the 18602 one.
One more line is worth saying plainly. ISO 18602 is a self-assessment framework, not a certificate. Your assessment can be demonstrated by you, by your customer, or by an independent third party, but there is no such thing as being certified to ISO 18602.
Frequently asked questions about ISO 18602
Short, plain answers to the questions that come up most about ISO 18602.
What is ISO 18602?
ISO 18602 is the international standard, published in 2013, that sets out how to assess whether a packaging system's weight or volume has been reduced to the minimum consistent with what the packaging has to do. It is the optimization standard in the ISO 18600 packaging and environment series.
Is ISO 18602 a certification?
No. It is a self-assessment framework you conform to and document, not a scheme you get audited and certified against.
The standard says the demonstration can be made by a first party, a second party such as your customer, or an independent third party. None of that is certification.
What edition of ISO 18602 is current?
The 2013 first edition, published on 15 January 2013, is still the current one. It was produced by ISO technical committee TC 122 on packaging, subcommittee SC 4.
Does ISO 18602 mean using as little packaging as possible?
No, and this is the most common misreading. The standard aims for the minimum adequate weight or volume, which means the least you can use while performance and consumer acceptability stay intact.
It explicitly allows packaging to get heavier where that prevents damage or loss of goods.
Is ISO 18602 mandatory?
The standard itself is voluntary, and nobody is legally required to use ISO 18602 by name. The underlying obligation is not optional though.
From 1 January 2030 EU packaging law requires minimised packaging and documented proof of it, so most producers will need an assessment of this kind whether or not they call it ISO 18602.
How does ISO 18602 relate to the EU packaging rules?
The regulation asks producers to identify, for each performance criterion, the design requirement that stops the pack getting any lighter or smaller. That is exactly what ISO 18602 calls a critical area.
The regulation does not reference the standard though, so ISO 18602 is a way of doing the work rather than a route to compliance.
What is the difference between ISO 18602 and EN 13428?
They are the international and European versions of source reduction. EN 13428:2004 is harmonised under EU Directive 94/62/EC and is the one European packaging conformity has historically leaned on.
ISO 18602 is the international standard used worldwide. Both look at minimum weight and volume, hazardous substances and the four heavy metals.
Does ISO 18602 cover packaging design and material choice?
No. Packaging design, including which material you pick, is outside its scope, and swapping to a lighter material does not count as optimization. ISO 18602 only asks whether the material you have already chosen is being used efficiently.
