| Full title | Information technology. Generic cabling. Introduction to the MICE environmental classification |
| Publisher | ISO and IEC, joint technical committee ISO/IEC JTC 1, subcommittee SC 25 |
| Current edition | Edition 1.0 (2007-11) with Amendment 1 (2012-12) and Amendment 2 (2019). Also available as a consolidated version including both amendments |
| Type | Technical Report, type 3 (informative) |
| Status | Current. Confirmed at review in 2018 |
| Related standards | ISO/IEC 11801-1, ISO/IEC 11801-3, IEC 61918, IEC 60721 series |
What it covers
ISO/IEC TR 29106 introduces the concepts behind the MICE environmental classification used in ISO/IEC generic cabling standards. It also explains the sources used to set the boundaries between MICE levels.
It is a type 3 Technical Report. It collects reference data rather than setting requirements. The normative MICE table that installations are specified against is in ISO/IEC 11801-1. Amendment 2 (2019) replaced the TR’s Table 1, originally taken from ISO/IEC 24702:2006, with the table from ISO/IEC 11801-1:2017. It also updated the references to the ISO/IEC 11801-1 to -6 series.
Structure
| Clause | Content |
|---|---|
| 4.1 | The MICE elements and how a classification is written |
| 4.2 | Channel environment: how MICE can vary along a channel, and the local environment |
| 4.3 | Component selection, with Table 1, details of environmental classification |
| 5.2 | Mechanical environment, with the derivation of the boundaries (Table 2) |
| 5.3 | Ingress protection and climatic environment (Tables 3 and 4) |
| 5.4 | Chemical environment (Table 5) |
| 5.5 | Electromagnetic environment (Table 6) |
The source documents behind the boundaries include IEC 60721-1 and IEC 60721-3-3 (environmental conditions), IEC 60654-4 (corrosive influences), IEC 60068-2-5 (solar radiation), and the IEC 61000-2-5, 61000-6-1 and 61000-6-2 EMC standards.
The MICE method
| Element | Describes | Parameters in Table 1 |
|---|---|---|
| M | Mechanical | Shock and bump, vibration, tensile strength, crush, impact, bending, flexing and torsion |
| I | Ingress | Particulate ingress and liquid (jets and immersion) |
| C | Climatic and chemical | Ambient temperature, rate of temperature change, humidity, solar radiation, liquid and gaseous pollution |
| E | Electromagnetic | Electrostatic discharge, radiated and conducted RF, fast transients, surge and magnetic fields |
A location is written as MaIbCcEd, where each suffix is 1, 2 or 3. M1I1C1E1 is the most benign environment and M3I3C3E3 the harshest in scope. The ISO/IEC 11801-3 page in this library shows typical uses of each level.
- Each element is classified by the most demanding parameter in its group.
- Component selection can still take account of every parameter in the group, including those less demanding than the overall grade.
- The classification may change along a channel. The TR’s example runs from M1I1C1E1 in the telecommunications room to M3I3C3E3 at the automation island.
- MICE is intended to cover about 80 % of the environments cabling may be exposed to. Environments beyond M3I3C3E3 need special handling.
Selected values from Table 1
These values are from Table 1 as replaced by Amendment 2, which matches ISO/IEC 11801-1:2017. Refer to the current edition of ISO/IEC 11801-1 for the full table.
| Parameter | Level 1 | Level 2 | Level 3 |
|---|---|---|---|
| Impact (M) | 1 J | 10 J | 30 J |
| Crush (M) | 45 N over 25 mm | 1 100 N over 150 mm | 2 200 N over 150 mm |
| Particulate ingress, max. diameter (I) | 12.5 mm | 50 µm | 50 µm |
| Liquid (I) | None | Intermittent liquid jet, up to 12.5 l/min, 6.3 mm or larger jet, at more than 2.5 m | As level 2, plus immersion up to 1 m for up to 30 min |
| Ambient temperature (C) | -10 °C to +60 °C | -25 °C to +70 °C | -40 °C to +70 °C |
| Humidity (C) | 5 % to 85 % non-condensing | 5 % to 95 % condensing | 5 % to 95 % condensing |
Mitigation and the local environment
The environment to classify is the one local to the cabling. With no protection, the local environment is the same as the overall environment at that point.
Where technical or economic limits rule out components that suit the overall environment, mitigation or isolation can change one or more of the M, I, C or E conditions local to the cabling. This normally means alternative pathways or pathway systems that protect the cable. Components then only need to suit the improved local environment.
How it relates to other standards
- ISO/IEC 11801-1 holds the normative environmental classification used across the series.
- ISO/IEC 11801-3 applies MICE to industrial premises.
- IEC 61918 covers installation in industrial premises. The TR refers to it for installation-specific parameters such as tensile force and bending.
- ANSI/TIA-568.5 refers to MICE1 conditions for its single pair cabling scope.
What it means in practice
- Classify each location along the route, not just the building as a whole.
- Check component datasheets state the MICE level, or the parameters needed to judge it, for each element.
- Where suitable components are not practical, consider protecting the cabling with a pathway system and record the improved local classification.
Related reading: IP ratings explained: IP67, IP68 and IP69K · Industrial connectivity for harsh environments.