Aluminium or Fibreglass (FIBRA)? Choosing an Insulated Ladder

Aluminium ladders and scaffolding are the right tool in the vast majority of situations. They are lightweight, strong, corrosion-resistant, and easy to maintain. But they have one property that in certain situations stops being an advantage and becomes a serious risk: aluminium is an excellent conductor of electricity.

If you work near electrical cables, switchgear, or live machinery, you need a different material. That material is fibreglass – and COSMOS manufactures a dedicated range called FIBRA for exactly this purpose.

Why Is Aluminium Dangerous Near Electrical Installations?

Aluminium has an electrical resistivity of approximately 2.65 × 10⁻⁸ Ω·m – which in practical terms means that an aluminium ladder or tower scaffold in contact with a live conductor is immediately energised along its entire length. A person standing on an aluminium ladder and touching a live conductor completes the circuit, with potentially fatal consequences.

Even indirect contact carries serious risk. Depending on the voltage, an electrical arc can jump distances ranging from a few centimetres to several metres. A worker on an aluminium ladder positioned 30–50 cm from an unsheathed medium-voltage cable is in genuine danger.

This risk is well understood – which is why the category of insulated ladders and platforms, manufactured from fibreglass-reinforced plastic, exists. In English the material is commonly called GRP (glass-reinforced plastic); the Italian term is fibra di vetro, shortened to FIBRA in the COSMOS product range.

What Is Fibreglass and What Are Its Properties?

GRP is a composite material consisting of glass fibres embedded in polyester or epoxy resin. Unlike metals, it is an electrical insulator – this is its defining property for use in electrical environments.

Other GRP properties relevant to ladders and platforms:

Weight: fibreglass is heavier than aluminium at comparable strength. A FIBRA ladder will typically be heavier than its aluminium equivalent. This is relevant for day-to-day carrying and handling.

Strength: for structural purposes (ladders, beams), fibreglass is adequately strong, but it does not offer the same strength-to-thickness ratio as aluminium. Manufacturers compensate by using larger cross-section profiles.

Chemical resistance: GRP resists many acids, alkalis, and chemicals that would degrade aluminium. This makes it a suitable material for laboratories and chemical processing environments as well.

Temperature range: operating temperatures vary by product – check the temperature range in the specification of the individual product, especially for extreme conditions.

Service life: fibreglass is not susceptible to corrosion and requires no surface treatment. With proper care, its service life is comparable to that of aluminium.

Standard CEI EN 50528 – What It Requires

Insulated ladders and platforms made from GRP are not simply “ladders made from a different material” – they have their own technical standard: CEI EN 50528, published by the Italian electrotechnical standardisation body CEI (Comitato Elettrotecnico Italiano) as the national adoption of European standard EN 50528.

CEI EN 50528 establishes:

Voltage classes: the standard defines the maximum voltage for which a product is certified. The standard class for FIBRA ladders is:

• Up to 1,000 V AC (alternating current – mains power, industrial distribution)
• Up to 1,500 V DC (direct current – tram and trolleybus traction at 600–750 V, photovoltaics)

This class covers the vast majority of common industrial applications – low-voltage switchgear, live production lines, electrical work in the energy sector.

Testing of insulation properties: the manufacturer must demonstrate that the product meets the insulation requirements for the applicable voltage class. This involves dielectric testing to verify that the current passing through structural elements (rungs, stiles, joints) does not exceed permitted levels at the rated voltage.

Marking: a certified product must carry marking showing the voltage class, the manufacturer, and the reference standard. Without this marking, a ladder or platform cannot be considered certified for work near live electrical equipment.

Important clarification: certification to CEI EN 50528 does not mean the product can be used in direct contact with live conductors. The standard defines safety parameters for work in the vicinity of live electrical equipment – the specific safe working distances and conditions of use are governed by technical rules for electricity supply and must be addressed in the workplace risk assessment.

The COSMOS FIBRA Range – When to Choose It

COSMOS manufactures selected models from its catalogue in a FIBRA version – a fibreglass construction with CEI EN 50528 certification. This is a specialist, made-to-order product line rather than a standard off-the-shelf item; FIBRA versions are produced to specification using COSMOS's in-house engineering department.

Typical scenarios where FIBRA is the right choice

• Electricians and maintenance workers in switchgear rooms: working in electrical distribution rooms, replacing fuses, taking measurements at busbars – situations where the presence of a metal ladder near live parts is not acceptable.
• Industrial facilities with live machinery: manufacturing plants where machines operate under voltage and maintenance takes place in live conditions – chemical plants, food processing, paper mills.
• Traction: working near the overhead lines of trams, trolleybuses and metro systems (600–750 V DC). Czech railway traction (3 kV DC, 25 kV AC) is outside the scope of CEI EN 50528 – an insulated ladder is not sufficient there and the railway operator's rules apply.
• Photovoltaic installations: working on rooftop solar systems, where panels and cables are energised even without a grid connection (the panels generate voltage as long as light falls on them). PV DC voltages can reach several hundred volts.
• Laboratories and chemical processing environments: settings where a metal ladder would corrode, or where electrical safety is an integrated part of the facility's safety design.

When FIBRA Is Not Necessary – and Why You Shouldn't Buy It Unnecessarily

FIBRA is more expensive, heavier, and only available on order with a longer lead time. If you do not work near live electrical equipment, it offers no practical advantage over a standard aluminium product.

To be specific: if the electrical installation at your workplace has been isolated and secured (LOTO – lockout/tagout procedure), an aluminium ladder is just as safe as a fibreglass one.

The decision is therefore straightforward: if there is any possibility of live voltage on accessible parts in the vicinity of the work area, choose FIBRA. If you are working on safely isolated equipment or in a completely different environment, aluminium is the more economical and ergonomic choice.

How to Order a FIBRA Version from COSMOS

Because FIBRA is a made-to-order product, the ordering process differs slightly from the standard range:

• Contact us with a description of your scenario (type of work, voltage present nearby, required working height, number of users).
• We will identify the appropriate model from the standard COSMOS catalogue and its FIBRA equivalent.
• We will confirm availability and lead time from the Italian factory.
• We will supply the manufacturer's documentation with the FIBRA version and confirm the scope of CEI EN 50528 certification in our quotation.

FIBRA products are manufactured in Italy – please allow for a longer delivery time compared with products held in stock.

Practical Summary

• Aluminium is an excellent electrical conductor – never use it near live cables or energised equipment.
• Fibreglass (FIBRA) is an electrical insulator certified to CEI EN 50528 for work near voltages up to 1,000 V AC / 1,500 V DC.
• FIBRA versions are heavier and more expensive – choose them only where a genuine electrical risk exists.
• COSMOS manufactures FIBRA versions to order, using its in-house engineering team.

Not sure whether your situation calls for FIBRA or standard aluminium? Describe the scenario to us and we'll advise – no obligation, response within 24 hours.