Non-sparking tools and intrinsically safe equipment are often mentioned together as if they solve the same problem, but they address two entirely separate ignition mechanisms — mechanical impact and electrical energy — and using one where the other is needed leaves the actual hazard unaddressed.

What non-sparking tools actually do

Non-sparking hand tools are made from copper-beryllium, aluminium-bronze or similar alloys that produce fewer and cooler sparks on impact or friction against steel or concrete than conventional steel tools do. This is a mechanical ignition control, addressing the risk of a dropped or struck tool producing an incendive spark, and it has nothing to do with electrical ignition sources at all.

The limits of non-sparking tools

Non-sparking is a relative rather than absolute property, and these tools can still produce sparks under sufficiently severe impact, particularly when contaminated with grit, rust particles or aluminium residue that can act as an ignition catalyst on impact. They also tend to be softer than steel equivalents, wearing faster and requiring more frequent inspection and replacement, and treating them as an absolute guarantee against mechanical ignition rather than a meaningful risk reduction overstates what they provide.

What intrinsic safety means

Intrinsically safe equipment is designed so the electrical energy available within the circuit, under both normal operation and specified fault conditions, remains below the level capable of igniting the surrounding atmosphere through either a spark or a hot surface. This is achieved through circuit design limiting current, voltage and stored energy, rather than by containing an ignition source the way a flameproof enclosure does, which is why intrinsically safe equipment can often be opened and worked on in a live hazardous area where flameproof equipment cannot.

System certification, not just component certification

An intrinsically safe circuit’s certification depends on the whole loop — the field device, the cable parameters, and the associated barrier or isolator — and substituting a component, extending cable length beyond certified parameters, or connecting a non-certified device into the loop can invalidate the intrinsic safety of the entire circuit. This makes intrinsic safety a system property rather than a per-item label, which is a frequent source of unintended non-compliance during maintenance work.

Battery and portable device considerations

Portable equipment marked intrinsically safe is certified with specific batteries, and substituting a different battery type or brand, even one that fits physically and functions normally, can invalidate the certification because the stored energy characteristics differ from what was assessed. Battery replacement should follow the manufacturer’s specified type and, where required, occur outside the hazardous area.

For maintenance work where these tools are typically used, see maintenance and permit work inside hazardous areas.

Related standards

The standards below set the test methods and performance levels behind the equipment referenced in this note.

• ISO 12100 — Safety of machinery
• EN 388 — Gloves against mechanical risks
• EN 1149 — Electrostatic properties of protective clothing

Frequently asked questions