Insulating matting and floor plates per IEC 61111 — classes, inspection and why there is no class 00

The guide on insulating gloves (class 00-4) per IEC 60903 covers the most personal item of insulating PPE. This article covers a related but distinct item: electrically insulating matting and floor plates, standardised in IEC 61111, which form a barrier between the worker's feet (or standing position) and earth rather than between the worker's hands and a live conductor.

The voltage classes — and the class 00 that is missing

IEC 61111 classifies insulating matting by the maximum use voltage of the installation on which it may be used:

Class	Maximum use voltage (AC)
0	1,000 V
1	7,500 V
2	17,000 V
3	26,500 V
4	36,000 V

Note: this class range starts at 0, not at 00. IEC 60903 insulating gloves have a class 00 for use up to 500V, but IEC 61111 insulating matting has no equivalent class — the lowest matting class, 0, already covers up to 1,000V. Confusing the two numbering ranges, or assuming a "class 00 mat" exists because a "class 00 glove" does, is a straightforward but consequential mistake when specifying or ordering matting.

Fixed matting versus portable matting

IEC 61111 covers two broad forms of use, with different wear patterns:

Fixed matting, installed permanently in front of a switchboard, control panel or other location where live work or operation regularly takes place. It sees relatively controlled foot traffic but can still be exposed to dropped tools, trolley wheels or spilled liquids over a long service life.
Portable matting, carried to the work location and laid down temporarily for the duration of a specific job (for example inside a substation during switching operations, or under a ladder during overhead-line work). It sees more varied mechanical handling — rolling, folding, dragging — and is correspondingly more exposed to cuts, punctures and embedded debris picked up between uses.

No fixed retest interval — and no air-test equivalent

Unlike the glove guide's IEC 60903, which specifies a widely applied periodic electrical retest interval of around 6 months, IEC 61111 does not itself mandate a single universal retest interval for matting — the interval is instead set by the employer's maintenance procedure or the manufacturer's recommendation, informed by the type of use (fixed versus portable), the environment and the observed condition of the material. A periodic dielectric retest remains standard practice, but the exact interval is installation-specific rather than a fixed figure that applies everywhere.

Matting also has no equivalent to a glove's quick air test: a glove can be inflated to reveal a pinhole as a hiss or a bulge, but a flat sheet of matting cannot be tested that way. In practice this places more weight on a careful visual inspection before use — checking for cuts, punctures, embedded metal shavings or other conductive debris pressed into the surface, and any softening, cracking or swelling of the rubber that can indicate chemical attack or ageing — since a mechanical defect that would be obvious in a glove's inflation test has to be caught by eye alone on a mat.

A supplementary barrier, not a substitute for isolation

Insulating matting is a supplementary protective measure: it reduces the risk of a hazardous touch or step voltage reaching the worker through the feet, but it does not replace the primary safety measure of isolating and proving dead the circuit being worked on (see the guide on the 5-step LOTO procedure). Relying on matting as if it were a substitute for correct isolation — rather than as one layer in a wider set of protective measures — misunderstands its role.

Practical relevance

When assessing PPE and supplementary protective measures for a switchboard or work location (see also the guide on PPE in general and the guide on live working), it should be verified that the matting class matches the actual installation voltage, that fixed matting in front of switchboards is included in a documented periodic inspection regime rather than left unchecked once installed, and that portable matting is visually inspected before each use for cuts, punctures and embedded debris rather than assumed sound because it was sound the last time it was used.

Common mistakes

Assuming a class 00 insulating mat exists, by analogy with IEC 60903's class 00 glove — IEC 61111 matting classes start at 0 (1,000V), with no lower class available.
Treating matting as a substitute for isolation rather than as a supplementary barrier alongside correctly isolating and proving dead the circuit.
Skipping the visual inspection before use on the assumption that, because matting has no air test, no pre-use check is possible or necessary — a careful visual check for cuts, punctures and embedded debris remains essential precisely because no equivalent instrument test exists.
Leaving fixed matting in front of a switchboard unchecked indefinitely after initial installation, instead of including it in a documented periodic inspection interval appropriate to its use and environment.