DuctSeal LG Cable Duct Sealing System

Revolutionary Cable Support System
Unique backing design provides enhanced cable stability, reducing strain and movement within the duct.

Safe, MEKO-Free Formulation
Our advanced FyBrid sealing compound is non-hazardous, halogen-free, and environmentally friendly, delivering a secure and safe seal without harmful emissions.

High Pressure Resistance
Engineered for robust performance with proven sealing capability of up to 1.0 bar, suitable for a wide range of underground and pressurised environments.

Chemical Resistance for Utilities
Tested and effective against methane, chlorine, and hydrogen sulphide, making it ideal for water industry infrastructure and utility networks.

Hydrocarbon Protection
Suitable for petrol forecourts, fuel distribution sites, and other hydrocarbon-exposed environments, offering durable sealing performance.

Full Compliance with Industry Standards
Meets or exceeds DSEAR, WIMES, DCG, APEA Blue Book, and ATEX requirements for safety and performance.

Ultra-Low VOC Emissions
GreyStuff has achieved Indoor Air Comfort GOLD certification, confirming ultra-low VOC emissions for safer duct sealing installations.

Certified Indoor Air Quality
Independently tested to meet strict European indoor air quality standards, including BREEAM Exemplary Level, EMICODE EC1 Plus, French A+ and EU Taxonomy criteria.

Sustainable Duct Sealing
Ideal for cable duct sealing projects where low emissions, indoor air quality and long-term environmental performance are important.

Enhanced Hygiene Protection
Formulated to resist bacterial and fungal growth, ensuring long-term reliability in damp or contaminated ducts.

Minimal Cable De-Rating
With a 20mm seal thickness, thermal resistance is just 5.1 K/W, allowing cables to retain their full current-carrying capacity.

Watertight Barrier Protection
Prevents water ingress and protects against cable degradation and water treeing, extending cable lifespan.

British Made Quality
Proudly designed, developed, and manufactured in the UK, ensuring excellent adhesion, durability, and consistent performance.

Fast & Simple Installation
Designed for quick application in multiple cable scenarios, without the need for special tools.

• Up to 2 hours (120 mins) Fire Resistance (45 mins → sealant exposed, 2 hours → sealant un-exposed)

• BS EN 1366-3:2021+A1:2024 which supersedes BS EN 1366-3:2009

• Cables tested: Small, Medium, Telecommunication & Bundles

• Cable types: NYY-O, HO7V-K, J-Y(ST) Y

• Warrington Fire cable Ref: (B), (F) & (E)

• Tested in penetrations up to 150mm (6 inches) in diameter

• Tested in horizontal 140mm thick low-density concrete walls (no duct or sleeve)

• Tested at Warrington Fire (Exova)

Indoor Air Comfort GOLD and Zero MEKO Protection

GreyStuff has been independently tested for ultra-low VOC emissions and has achieved Indoor Air Comfort GOLD. This means it has been assessed against some of the strictest European indoor air quality requirements for construction products, including BREEAM Exemplary Level, EMICODE EC1 Plus, French A+ and EU Taxonomy criteria.

For DuctSeal LG installations, this is important because duct sealants are often applied in enclosed or restricted areas such as service risers, plant rooms, substations, chambers, utility spaces and ducted cable networks. A low-emission duct sealant helps support cleaner air during and after installation, making it a strong choice for engineers, installers and contractors working in demanding environments.

What Indoor Air Comfort GOLD Means

Indoor Air Comfort GOLD is a recognised certification for low product emissions. It brings together a wide range of European VOC emission requirements into one certification, helping show that a product supports better indoor air quality and sustainable building standards.

For specifiers and contractors, this helps make GreyStuff suitable for projects where air quality, low VOC emissions, sustainability and environmental performance are important.

Why Zero MEKO Matters

GreyStuff is formulated with zero MEKO. MEKO, also known as 2-butanone oxime, is used in some traditional sealants and can be released during the curing process. In comparison, GreyStuff avoids MEKO-based curing chemistry, helping reduce unnecessary exposure to MEKO-related emissions during installation.

This is especially beneficial for engineers who regularly work close to sealants, often by hand and in confined or poorly ventilated areas. Choosing a zero MEKO duct sealant helps support safer working conditions by reducing exposure to a substance associated with occupational health concerns.

Compared with MEKO-Containing Sealants

Some conventional sealants still use MEKO-based curing chemistry. When these products cure, they may release MEKO into the surrounding air. For engineers working directly over duct openings, or applying sealant in restricted spaces, this can create avoidable inhalation exposure.

GreyStuff provides a cleaner alternative by removing MEKO from the formulation. This helps reduce exposure during application and curing while still delivering the flexible, re-enterable, water and gas tight performance required from a professional duct sealing system.

Benefits for Engineers and Installers

Indoor Air Comfort GOLD: Independently tested for ultra-low VOC emissions and compliance with strict indoor air quality standards.

Zero MEKO formulation: Does not use MEKO-based curing chemistry, helping reduce unnecessary chemical exposure during installation.

Cleaner air during installation: Supports improved air quality in chambers, risers, plant rooms, substations and other enclosed work areas.

Better for frequent use: A more responsible choice for engineers and contractors who regularly apply duct sealants by hand.

Supports sustainable projects: Suitable for specifications where BREEAM, EMICODE, French A+, EU Taxonomy and low VOC requirements are important.

No compromise on performance: GreyStuff remains flexible, re-enterable, water and gas tight, while supporting a cleaner working environment.

A Cleaner Choice for Duct Seal LG

Duct Seal LG uses GreyStuff as part of a re-enterable duct sealing system designed to protect cable ducts from water, gas, smoke, vermin and harsh industrial environments. With Indoor Air Comfort GOLD and zero MEKO technology, it supports both reliable duct protection and a cleaner installation environment for the people applying it.

Electrostatic Properties

GreyStuff has been independently tested to assess its electrostatic behaviour in accordance with recognised industry standards for electrical insulation and static charge performance.

Testing was conducted to:

• BS EN 60079-32-2 / IEC 60079-32-1 (Surface Resistivity – electrostatic hazards guidance)
• BS EN 61340-2-3 (Volume Resistivity – resistance through material)

Test Results

• Surface Resistivity: > 2.0 × 10¹³ Ω/sq (at 25% RH)
• Volume Resistivity: > 1.7 × 10¹² Ω·m

One Kit Per Duct
Each kit includes all components required to seal one duct, based on the kit size selected.

Note: A standard caulking gun is required (not included but available separately). Depending on the cable fill percentage, one kit may seal more than one duct. For advice, contact our technical team on +44 (0)161 874 1480.

Cable Separation & Support
Correct separation is essential for performance. The patent-pending tubular rubber backing system can be configured in continuous strips, rings, or cross-shapes to provide support and separation for large single-core, trefoil, or triplex cables. This ensures safe spacing, prevents movement, and guarantees DSEAR-compliant trefoil sealing.

Running Water Conditions
For best results, ducts and cables must be dry and free from running water. Clean surfaces of all dirt, oil, and grease before applying GreyStuff or RedStuff. If running water is present, please call +44 (0)161 874 1480 for technical advice. In most cases, we recommend using a Kraso Mechanical Seal.

Cure Time
GreyStuff and RedStuff cure at approximately 3–4mm per day, depending on humidity and temperature. Higher humidity and warmer conditions accelerate curing.

Minimum seal depth: 20mm for effective performance.

Cleaning
Uncured material can be removed using solvent-based wipes. Once cured, the compound must be removed mechanically.

Health & Safety
Both GreyStuff and RedStuff are based on a neutral curing, MEKO-free system, making them non-hazardous and installer-safe during application.

Compliance      
DuctSeal LG is fully compliant with:

• WIMES (Water Industry Mechanical & Electrical Specifications)
• APEA Blue Book (petrol forecourts)
• ATEX & DSEAR (explosive atmospheres)
• DCG (Ducted Cable Guidance)
• Sewers for Adoption
• Network Rail PADS

Re-Entry & Removal
Once cured, the compound has a hardness similar to a rubber eraser. This allows ducts to be re-entered or resealed when required.

Always use sharp tools on de-energised cables. AC Cable Solutions accepts no responsibility for damage caused during re-entry.

Cable Suitability
GreyStuff and RedStuff are solvent-free, single-component systems that do not damage cable sheaths or stain duct surfaces.

Storage & Shelf Life
Store in a cool, dry location away from direct sunlight.

Shelf Life: 12 months unopened
After opening: reseal tightly and use within 1 month.

What makes DuctSeal LG different from other duct sealing systems?
DuctSeal LG combines unique daisy-chained circular foam backings with a flexible, intumescent, MEKO-free sealing compound (GreyStuff). This design delivers superior stability, prevents cable movement, and ensures long-lasting resistance against water ingress, toxic gases (methane, chlorine, hydrogen sulphide), hydrocarbons, and microbial attack. It is also fully compliant with WIMES, ATEX, DSEAR, and APEA standards, making it one of the safest and most reliable duct sealing solutions available.

Is DuctSeal LG safe to use in all environments?
Yes. DuctSeal LG is non-hazardous, halogen-free, and MEKO-free, ensuring safe installation in sensitive environments such as water treatment plants, data centres, telecom networks, petrol forecourts, and industrial facilities.

Can DuctSeal LG be used for retrofitting existing installations?
Absolutely. DuctSeal LG is a re-enterable duct sealing system, which means it can be installed during new projects or retrofitted into existing ducts. Future re-entry for cable upgrades or maintenance is straightforward and safe.

Is DuctSeal LG WIMES compliant?
Yes. DuctSeal LG complies with WIMES 3.02 (2019), clause 6.4.3.2(d), and is approved for use by all UK and Irish water authorities.

Can DuctSeal LG withstand chemicals and hydrocarbons?
Yes. DuctSeal LG is designed to resist a wide range of aggressive agents, including methane, chlorine, hydrogen sulphide, and hydrocarbons. This makes it suitable for petrol forecourts, wastewater plants, sewage pumping stations, and industrial sites.

How much pressure can DuctSeal LG withstand?
When installed correctly, DuctSeal LG achieves a gas- and water-tight seal up to 1.0 bar pressure, providing strong protection even in challenging environments.

How long does DuctSeal LG take to cure?
Cure rate is approximately 3–4mm per day, depending on humidity and temperature. A minimum of 20mm seal depth is required for full performance.

Does DuctSeal LG reduce cable performance?
No. At a 20mm seal depth, the thermal resistance is just 5.1 K/W, which means minimal cable de-rating and no loss of current-carrying capacity

How long will the seal last?
DuctSeal LG is designed for long-term durability in harsh underground and industrial conditions. With correct installation, it provides decades of service life, protecting cables against water treeing, chemical ingress, and environmental degradation.

Why choose AC Cable Solutions?
AC Cable Solutions is the exclusive UK & Ireland distributor of KRASO GmbH and the manufacturer of the GreyStuff & RedStuff sealing compound. All products are British made, rigorously tested, and compliant with international standards, ensuring the highest level of safety and performance. Our dedicated support team provides technical advice, training, and next-day delivery to keep your projects moving.