Nitrile Rubber Sheet UK: Oil-Resistant Industrial Sheeting
Nitrile rubber sheet (NBR) is the standard specification for any UK industrial application involving oil, fuel, hydraulic fluid, or hydrocarbon contact. Where SBR swells and loses integrity, and EPDM degrades rapidly, nitrile maintains its mechanical properties through the polar chemistry of its acrylonitrile groups. This guide explains the mechanism of oil resistance, how to select the correct ACN grade, and how nitrile performs across every major industrial sector where oil-resistant rubber sheet is specified.
How Nitrile Rubber Resists Oil: The Chemistry
Understanding why nitrile resists oil — rather than simply accepting that it does — is what enables confident specification across the range of service conditions you will encounter.
Nitrile rubber is a copolymer of acrylonitrile (ACN) and butadiene monomers. The butadiene sections give the polymer its elastomeric flexibility, whilst the acrylonitrile groups provide chemical resistance. The mechanism is polarity: the nitrile group (–C≡N) in each acrylonitrile unit carries a strong electric dipole — the triple bond between carbon and nitrogen creates a highly polar site in the chain. Mineral oil, diesel, petrol, and most lubricating fluids are non-polar hydrocarbons. The principle of "like dissolves like" governs polymer swelling: a non-polar liquid cannot solvate a polar polymer, and vice versa. The concentrated polarity of the ACN groups in the nitrile backbone prevents hydrocarbon molecules from penetrating between the polymer chains — there is simply no chemical affinity to drive absorption.
The higher the proportion of ACN in the copolymer, the more polar the polymer, and the stronger the resistance to hydrocarbon absorption. This is the fundamental relationship that governs ACN grade selection.
ACN Grade Comparison: Selecting the Right Nitrile
Commercial nitrile rubber sheet is produced in three principal ACN grade bands. The selection involves a trade-off between oil resistance and low-temperature flexibility — as ACN content rises, oil resistance improves but the glass transition temperature (Tg) rises too, making the rubber stiffer at low temperatures.
| Grade | ACN Content | Oil Resistance | Fuel Resistance | Low-Temp Flex | TR10 (°C) | Volume Swell in IRM 903 Oil | Best Applications |
|---|---|---|---|---|---|---|---|
| Low ACN | 28–33% | Moderate | Moderate | Excellent | -35°C | 40–70% | Cold-store gaskets, Arctic fuel seals, applications needing oil resistance to -30°C+ |
| Medium ACN | 33–36% | Good | Good | Good | -25°C | 20–40% | General industrial (workshops, plant rooms, hydraulics), standard UK specification |
| High ACN | 38–45% | Excellent | Excellent | Moderate | -10°C | 10–20% | Fuel system seals, offshore oil deck matting, severe hydrocarbon exposure |
For the majority of UK industrial applications — workshop flooring, plant room matting, hydraulic equipment areas — medium ACN (33–36%) is the correct standard specification. High ACN grades are reserved for immersion or prolonged contact with aggressive hydrocarbons such as ASTM Reference Fuel C (a severe fuel swell test fluid) or aviation turbine fuel.
Technical Properties of Nitrile Rubber Sheet
The following table covers the full property profile of medium-ACN commercial nitrile rubber sheet — the standard grade available as cut-to-size sheet in the UK:
| Property | Typical Value | Test Standard |
|---|---|---|
| Hardness (Shore A) | 40–80 (std 60 ±5) | BS ISO 7619-1 |
| Tensile strength | 10–18 MPa | BS ISO 37 |
| Elongation at break | 200–400% | BS ISO 37 |
| Compression set (22h/70°C) | <30% | BS ISO 815-1 |
| Temperature range (continuous) | -25°C to +120°C | — |
| Temperature range (short-term) | to +150°C | — |
| Volume swell in IRM 903 oil (70h/100°C) | <40% (medium ACN) | BS ISO 1817 |
| Volume swell in ASTM Fuel C (70h/23°C) | <65% (medium ACN) | BS ISO 1817 |
| Water absorption (72h/23°C) | 3–6% | BS EN ISO 62 |
| UV resistance | Poor — surface crazing outdoors | BS ISO 1431-1 |
| Ozone resistance | Poor — cracks under tension outdoors | BS ISO 1431-1 |
| Abrasion resistance (DIN) | 80–150 mm³ | DIN 53516 / BS ISO 4649 |
| Density | 1.30–1.45 g/cm³ | BS EN ISO 2781 |
| Colour (standard) | Black | — |
Industrial Applications by Sector
Automotive Workshops and Vehicle Servicing
The automotive workshop is the most common UK specification environment for nitrile rubber sheet. Floor areas beneath vehicle lifts, around oil drains, and in lubrication bays are subjected to continuous contamination with engine oil, gear oil, automatic transmission fluid, power steering fluid, brake fluid, and coolant. Standard 6mm medium-ACN nitrile sheet withstands this combination of fluids without swelling or surface degradation.
Workbench matting in workshops — where mechanics lay components directly on rubber — is typically 3mm nitrile, providing chemical resistance and a non-slip surface for handling oily parts. Ramp overlays on vehicle ramps use 6mm or 8mm nitrile to maintain anti-slip performance under combined oil and tyre contact. Our nitrile rubber sheet is the standard UK specification for these automotive applications.
Oil and Gas / Offshore Installations
Offshore platforms and onshore oil processing facilities present the most chemically severe environments for rubber sheet. Deck matting on offshore platforms — walkways, work platforms, and equipment surrounds — operates in constant hydrocarbon contamination combined with salt spray and UV exposure. High-ACN nitrile is specified for deck matting where the hydrocarbon exposure is severe; the ozone and UV limitation is managed by protective coatings or enclosures rather than compound substitution, as no single rubber combines nitrile's oil resistance with EPDM's weathering resistance.
Gaskets for hydrocarbon process pipework — flanged joints on crude oil, condensate, and associated gas lines — use high-ACN nitrile sheet cut from roll stock to flange size. BS 2494 (elastomeric seals) and relevant pressure system regulations (PSSR 2000) govern the specification and testing regime.
Hydraulic Engineering
Hydraulic systems throughout UK industry — from injection moulding machines and metal presses to agricultural machinery and civil engineering plant — use mineral-based hydraulic oil (typically HM grade to ISO 6743-4). Nitrile rubber is the standard sealing compound for hydraulic systems because medium-ACN nitrile swells less than 40% in IRM 903 reference oil at 100°C — a performance level that maintains dimensional stability in dynamic seal applications.
Our nitrile rubber sheet black is suitable for gasket cutting for hydraulic manifolds, accumulator seals, and static compression seals in hydraulic systems. Dynamic hydraulic seals (O-rings, lip seals) are typically moulded rather than cut from sheet, but static face seals and valve seats are commonly cut from sheet stock.
Food Processing — Food-Grade Nitrile (Critical Distinction)
Nitrile rubber is used in food processing environments, but the compound must be specified correctly. Standard commercial nitrile sheet contains vulcanisation accelerators, plasticisers, and antioxidants that are incompatible with food contact. Food-grade nitrile is a specialist compound formulated to eliminate or replace these additives with materials approved under:
- EC Regulation 1935/2004 (framework for food contact materials) — the fundamental EU-derived UK regulation requiring that food contact materials do not transfer substances to food in quantities that could endanger human health or cause unacceptable changes in composition or organoleptic characteristics.
- FDA 21 CFR 177.2600 (USA) — rubber articles intended for repeated use in food contact, specifying permitted ingredients and their limits.
- BfR XXII (Germany) — rubber for food contact, widely referenced in European food-grade specifications.
When specifying nitrile sheet for food processing — conveyor belt edge strips, gaskets for food-grade pipework, machine seals — always request documentation confirming compliance with EC 1935/2004 and the relevant specific migration test results. Do not assume standard commercial nitrile is food-approved; it is not.
Printing Industry — Roller Covers and Blankets
Offset and flexographic printing uses rubber-covered rollers to transfer ink. Nitrile rubber's resistance to the hydrocarbon-based solvents in printing inks and cleaning agents makes it the standard compound for printing roller covers and blankets. The specific compound formulation is tuned for the printing application, but all are NBR-based. Sheet stock is used for cutting blanket patches and roller repairs in-house.
Aviation Ground Support
Ground support equipment (GSE) at UK airports — towbars, ground power units, fuelling rigs — operates in environments with jet fuel (Jet A-1, kerosene-based) and hydraulic fluid spillage. Nitrile matting and gasket sheet is used throughout GSE maintenance workshops. High-ACN nitrile is preferred for direct fuel contact applications; medium-ACN for general workshop floor matting where fuel contact is incidental.
Nitrile Sheet vs Neoprene Sheet
The two compounds that buyers most often compare are nitrile and neoprene (polychloroprene, CR). Neoprene offers a useful intermediate position between nitrile's outstanding oil resistance and EPDM's outstanding weathering resistance:
| Property | Nitrile (NBR medium ACN) | Neoprene (CR) | When to Prefer Neoprene |
|---|---|---|---|
| Oil resistance | Good–Excellent | Moderate | Nitrile always wins on oil |
| Fuel resistance | Good–Excellent | Moderate | Nitrile for fuel immersion |
| UV resistance | Poor | Good | Neoprene for outdoor with incidental oil |
| Ozone resistance | Poor | Good | Neoprene for outdoor exposure |
| Temperature range (max) | +120°C | +120°C | Similar — compound-specific |
| Flame resistance | Poor | Good (self-extinguishing) | Neoprene for fire-risk environments |
| Water resistance | Moderate (absorbs some water) | Good | Neoprene for wet outdoor service |
| Relative cost | Moderate–High | Moderate–High | Similar price bracket |
The decision rule is straightforward: if oil resistance is the primary requirement and the installation is indoors or sheltered, specify nitrile. If the application is outdoor or semi-outdoor with only incidental or moderate oil contact — marina fenders, outdoor machine mounts, service yard bunds — specify our neoprene rubber sheet for the better weathering profile.
Available Thicknesses and Sizes
Nitrile rubber sheet is available cut to size from continuous rolls. The full range covers 1.5mm to 25mm thickness in widths up to 1,200mm, with most common thicknesses ex-stock for same-day dispatch.
| Thickness | Typical Application | Load Type |
|---|---|---|
| 1.5mm – 2mm | Precision gaskets, thin seals, liner sheets | Low-pressure sealing |
| 3mm | Workbench matting, light-duty gaskets, component mats | Foot traffic, component handling |
| 4mm | General gaskets, protective lining | Medium compression sealing |
| 6mm | Workshop floor matting, garage flooring, plant room overlay | Foot traffic + vehicle drip zones |
| 8mm | Heavy workshop floors, under-vehicle service areas | Foot + light wheeled |
| 10mm | Forklift routes in oil environments, heavy plant bases | Heavy wheeled traffic |
| 12mm – 15mm | Anti-vibration pads in oil environments, heavy equipment | High compressive load + vibration |
| 20mm – 25mm | Structural isolation in petrochemical plants | Structural compression + isolation |
Specification and Ordering: What to Tell Your Supplier
When placing an order or requesting a quotation for nitrile rubber sheet, provide the following information to ensure the correct product is supplied:
- ACN grade: Specify "medium ACN" (33–36%) for general industrial use, "high ACN" for severe fuel or hydrocarbon immersion, or "low ACN" for cold-temperature applications below -25°C.
- Hardness: Standard is 60 Shore A ±5. Specify if you need a softer (40–50 Shore A) or harder (70–80 Shore A) grade.
- Thickness: In millimetres.
- Dimensions: Width and length in millimetres. For cut-to-size orders, specify whether you want the full roll width or a slit width.
- Food grade: If required, state "EC 1935/2004 compliant food-grade nitrile" explicitly — and request the compliance documentation.
- Data sheet: For critical sealing or structural applications, request the compound data sheet confirming all key properties tested to named British or ISO standards.
Frequently Asked Questions
What is the difference between nitrile sheet and standard rubber sheet?
"Standard rubber sheet" in the UK typically refers to SBR (styrene-butadiene rubber) — the general-purpose compound used for industrial flooring and matting. Nitrile (NBR) is a specialist oil-resistant compound that costs more than SBR but is essential wherever hydrocarbon exposure is present. If the application involves oil or fuel contact, SBR will fail; nitrile will not. For oil-free flooring and matting, SBR is the correct economical choice.
How long does nitrile rubber sheet last in an oil environment?
In a typical automotive workshop with regular but not continuous oil immersion, medium-ACN nitrile floor matting has a service life of 5–10 years under normal foot traffic conditions. Continuous immersion in hot oil or aggressive fuels reduces this significantly. Nitrile that is mechanically stressed (heavy wheeled traffic, dragging loads) in an oil environment will show surface degradation — abrasion combined with chemical softening — and should be inspected annually.
Can I use nitrile sheet for an outdoor fuel bund liner?
Nitrile is chemically suitable for fuel containment in bund liners, but the UV and ozone limitation means it will degrade in permanently outdoor exposed installations over 2–5 years. For outdoor fuel bunds, either protect the nitrile from UV (cover, gravel ballast, or coating), or specify a compound specifically approved for outdoor fuel containment — HDPE geomembrane or specialist fuel-rated EPDM liners are commonly used for permanent outdoor bunds. Nitrile sheet is more commonly used for internal bund floors and walls within covered buildings.
Does nitrile rubber sheet comply with COSHH requirements for oil-contact applications?
COSHH (Control of Substances Hazardous to Health) is a risk assessment and control obligation on the employer, not a product standard. Specifying nitrile rubber matting to resist oil penetration reduces the risk of slip hazards from oil-contaminated floors, which contributes to the COSHH risk assessment for slipping and falling. However, COSHH compliance requires a full assessment of the specific workplace hazards — the rubber matting is one control measure within a broader risk management framework.
Ready to specify? View our full range of nitrile rubber sheet and nitrile rubber sheet black, or visit the rubber sheet UK guide for compound selection and cut-to-size ordering — same-day dispatch for orders placed before 2pm.
