IEC 60068 is the international standard set for environmental testing of electrical and electronic products. When a technical requirement says “tested to IEC 60068-2-1” or “tested to IEC 60068-2-30”, the reader needs to know immediately what that test is, how severe it is, and who has the authority to decide the severity level.
This article explains the three document groups that make up the standard set, how to read test code letters, and the points most often misread when IEC 60068 is quoted in technical documentation.
1. What is IEC 60068 and which products does it cover?
IEC 60068 is a collection of environmental test methods used to assess how products behave under conditions such as cold, dry heat, damp heat, vibration, shock, corrosion, dust, water and low air pressure. The standard set addresses electrical and electronic products, components, assemblies and complete equipment.
The key point to understand: IEC 60068 provides methods and ranges of severity levels; it does not prescribe which level a given product must withstand. Selecting the test and the severity level belongs to whoever writes the requirement — the customer, the manufacturer, or an industry standard. That is why a test report stating only “passed IEC 60068” without naming the part, the level and the duration cannot be verified against anything.
2. The three document groups
| Group | Function | Examples |
|---|---|---|
| IEC 60068-1 | General provisions and guidance: terminology, standard atmospheric conditions, principles for choosing severity levels | Measurement and test conditions, how to report results |
| IEC 60068-2-xx | The individual tests; each part corresponds to one agent or one family of agents | 60068-2-1 (cold), 60068-2-6 (sinusoidal vibration), 60068-2-11 (salt mist) |
| IEC 60068-3-x, 60068-4, 60068-5-2 | Supporting documents: technical guidance, chamber performance confirmation, how to choose between tests, terminology | 60068-3-5 and 3-6 (chamber confirmation), 3-8 (selecting vibration tests) |
These three groups play different roles. Part 2 is what you use to run a test; Part 3 is what you use to run the test correctly — making sure the chamber, the measurement chain and the mounting do not introduce errors of their own.
3. Classifying tests by agent family
| Agent family | Typical tests | Question the test answers |
|---|---|---|
| Temperature | Test A (cold), Test B (dry heat), Test N (change of temperature) | Does the product still work and remain intact when temperature changes or reaches extremes? |
| Humidity | Test Cab, Test Db, Test Z/AD, Test Cx, Cy | Do humidity and condensation degrade insulation, cause corrosion or functional faults? |
| Mechanical | Test Fc, Fh, Fi, Ff/Fj, Ea, Ei, Ga, Eh | Do vibration and shock cause cracks, loosened joints, structural failure or intermittent faults? |
| Transport and handling | Test Ec, Ee | Does the product survive drops, toppling, edge impacts and loose cargo during transport? |
| Corrosion and chemical environment | Test Ka, Kb, Kc, Kd, Ke | How do salt-laden or industrial atmospheres affect contacts and coatings? |
| Dust, water, biological | Test L, Test R/S/T/U, Test J | Can foreign objects and biological humidity penetrate and damage the equipment? |
| Soldering and components | Test T (Ta/Tb/Td), Test Te/Tc, Test U, Test Xw1 | Do components withstand soldering heat, lead robustness and whisker growth? |
| Others | Test M (low air pressure), Test Sa (solar radiation), Test XA/Xb/Xc | Application-specific conditions: altitude, outdoor exposure, solvents, marking abrasion |
4. How to read a test code
Test names in IEC 60068-2 normally carry two layers of code: a capital letter (A, B, C, E, F, J, K, L, M, N, Q, R, S, T, U, X) and a second, lower-case letter indicating the variant (for example Ab and Ae, Bb and Bd, Na and Nb).
| Common codes | Family | What to remember |
|---|---|---|
| Ab, Ae | Test A — Cold | Two variants differing in how the specimen reaches temperature and when functionality is checked |
| Bb, Bd | Test B — Dry heat | The same logic with the temperature direction reversed |
| Cab | Test C — Damp heat, steady state | One constant temperature and humidity condition held throughout the test |
| Db | Test D — Damp heat, cyclic | Repeating cycles that include a condensation phase |
| Fc, Fh, Fi | Test F — Vibration | Sinusoidal, broad-band random, mixed mode |
| Ea, Ec, Ee | Test E — Shock and rough handling | Mechanical shock, rough handling, loose cargo |
| Ka, Kb, Kc, Kd, Ke | Test K — Corrosion | Salt mist, cyclic salt mist, SO₂, H₂S, mixed gas |
| Ta, Tb, Td, Te/Tc, Tf | Test T — Soldering | The family of tests related to soldering processes |
| Xb, Xc, Xw1 | Test X — Miscellaneous | Marking abrasion, contamination by fluids, solder whiskers |
5. Where misreadings usually happen
- Assuming the standard chooses the level. The standard offers a range of options; the requirement writer must select and state one.
- Confusing the test with the condition. The same test name at different temperatures, humidity levels or durations leads to entirely different conclusions.
- Ignoring the supporting documents. If the chamber performance has never been confirmed, the result is hard to defend in a dispute.
- Not recording how the specimen was mounted. In vibration and shock testing, mounting can change the resonant frequency and the amplitude actually seen by the specimen.
- Not defining acceptance criteria. Decide in advance which failures are critical, which are acceptable, and at which points functionality is checked.
- Using test results to infer service life. Environmental testing to IEC 60068 answers “does it survive this condition”; it does not automatically yield a lifetime in years.
6. Who benefits from this standard set?
- Equipment manufacturers: they need evidence of environmental robustness before selling or before entering a supply chain.
- Importers: they need to match customer or certification requirements against the methods actually available in a laboratory.
- Design teams: they use the results to find design weaknesses, not merely to obtain a certificate.
- Testing bodies: they need the right test, the right level, the right acceptance criteria and a traceable record.
A practical observation: many companies send samples for testing but keep no record of the test conditions (temperature and humidity over time, mounting arrangement, agreed acceptance criteria). When a customer or an inspector asks for justification, the absence of that data erases the value of an otherwise correctly performed test.
7. Frequently asked questions
Can IEC 60068 replace MIL-STD-810?
No. They are two different method systems with different philosophies for choosing severity and different target products. Which one applies depends on customer requirements, market and industry sector.
What does it mean for a product to “pass IEC 60068”?
By itself, nothing definite. You must state the part (for example 60068-2-1), the test code (Ab or Ae), the temperature, the duration and the acceptance criteria.
Must testing be done in an accredited laboratory?
Not in every case. But when a third party has to accept the result, laboratory competence and the accredited scope are decisive for how much the result is worth.
How many samples are enough for an environmental test?
There is no universal number. Sample size depends on the objective (qualitative assessment or trend monitoring), the value of the samples, and the acceptance criteria agreed in advance.
Can a slower, cheaper test be substituted?
Only when the requirement document allows it. Substituting a test without documenting the change is a common root cause of disputes when goods are returned.
Which document should a newcomer read first?
Start with IEC 60068-1 for terminology and principles, then move to the Part 3 guidance that corresponds to the test you are about to perform.
8. Conclusion
IEC 60068 is a set of methods, not a set of prescribed levels. Understanding the three document groups and how test codes are read helps companies avoid quoting a standard by its correct name while misstating what it actually requires.
Three things to do immediately: record the full standard part and test code in technical documentation; define acceptance criteria before testing; and confirm chamber performance before issuing conclusions that may be challenged.
References
- IEC 60068-1 — Environmental testing: General and guidance.
- IEC 60068-2 (parts) — Environmental testing: Tests.
- IEC 60068-3 (parts) — Supporting documentation and guidance.
- IEC 60068-5-2 — Guide to drafting test methods: Terms and definitions.
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This article is interpretive content written by our team; it is not legal advice. Companies should review the original text of the applicable regulations and standards before applying them to a specific product.
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