Yet these are precisely the environments where maintenance of protective coatings is most critical. Offshore structures in corrosive marine atmospheres, refinery piping in hydrogen sulphide service, LNG plant structural steel subject to cryogenic temperature cycling — all require periodic coating maintenance that must be executed in an environment where the standard surface preparation method is banned.
This guide covers the regulatory framework for hazardous area surface preparation, what “ATEX Zone 1” actually means for the choice of tools and methods, and the documented capabilities of the only currently certified hand-held power tool for surface preparation comparable to SSPC-SP10 in Zone 1.
The ATEX / IEC 60079 Regulatory Framework
The regulation of equipment for use in explosive atmospheres is governed by two parallel frameworks that are technically harmonised:
In Europe: ATEX Directive 2014/34/EU (equipment) and Directive 1999/92/EC (worker protection). Equipment used in potentially explosive atmospheres must carry ATEX certification and marking.
International: IEC 60079 series of standards — adopted in whole or in part by the US (NEC Article 505), Canada, Australia, the Gulf states and most jurisdictions operating offshore and industrial facilities with international operators. Major operators (ExxonMobil, Shell, BP, Saudi Aramco, TotalEnergies) specify IEC 60079 compliance in their global equipment standards regardless of local regulatory requirements.
In North America, the equivalent classification system uses NEC (National Electrical Code) Class/Division and Class/Zone designations. NEC Zone 1 corresponds directly to IEC/ATEX Zone 1.
Understanding Zone Classification
| Zone | Definition | Typical Locations |
|---|---|---|
| Zone 0 | Explosive atmosphere present continuously or for long periods | Inside storage tanks, enclosed vessels containing flammable liquids or gases |
| Zone 1 | Explosive atmosphere likely to occur in normal operation occasionally | Offshore platform process decks, pump rooms, compressor areas, refinery units in operation, LNG bund areas, fuel loading facilities |
| Zone 2 | Explosive atmosphere not likely to occur in normal operation; if it does, only infrequently and briefly | Areas surrounding Zone 1 equipment, storage areas for flammable substances, battery rooms |
Zone 1 is the most operationally critical zone for surface preparation maintenance because it encompasses all the active process areas of a facility — the areas that must remain in service and that are simultaneously most exposed to corrosive conditions.
Why Abrasive Blasting Is Prohibited in Zone 1
The ignition mechanism of abrasive blasting is the generation of incandescent and thermite-type sparks at the impact point. When high-velocity abrasive particles (steel grit, aluminium oxide, garnet) impact a metal surface, the kinetic energy is converted to heat — generating sparks capable of igniting flammable atmospheres. Aluminium oxide on steel is particularly hazardous due to thermite-type reactions; steel grit and garnet generate incandescent friction and impact sparks. The energy and temperature of these sparks is sufficient to ignite flammable vapour-air mixtures, particularly for gases in the lower explosion limit (LEL) range.
This prohibition applies regardless of the abrasive material used. Steel grit, garnet and mineral abrasives all generate incandescent impact and friction sparks on steel. Aluminium oxide is particularly hazardous: it generates thermite-type sparks when impacting steel — Al₂O₃ reacts with iron oxide formed at the impact point (2Al + Fe₂O₃ → Al₂O₃ + 2Fe + heat), releasing high-temperature incandescent particles. There is no blasting medium that can be used safely in Zone 1. There is no ATEX-certified abrasive blasting equipment for Zone 1 — the physics of the process are incompatible with Zone 1 operation.
Angle grinders — even with non-sparking accessories — present a similar prohibition in Zone 1. Standard electric angle grinders are not ATEX-certified for Zone 1 use. Mechanical contact of a rotating tool against steel at high speed generates friction heat and potential ignition energy.
What ATEX Certification Actually Means for Surface Preparation Tools
For a tool to be certified for use in Zone 1, it must be assessed and certified against IEC 60079-0 (general requirements) and the applicable protection concept standard. The ATEX marking conveys specific technical information:
| Code | Meaning |
|---|---|
| Ex | Equipment certified for use in explosive atmospheres |
| II | Equipment Group II — surface industries (not underground mining) |
| 2G | Category 2, gas atmosphere — suitable for Zone 1 use (occasional explosive atmosphere) |
| c | Protection concept: constructional safety — the equipment is designed and manufactured so it does not generate ignition sources (sparks, excessive surface temperature) during normal operation, including during the working action |
| IIA | Gas group: covers methane, propane, butane, acetone and ammonia. Does NOT cover Group IIB gases (H₂S / hydrogen sulphide, ethylene, ethylene oxide) or Group IIC gases (hydrogen, acetylene). Critical for refinery and sour service applications: H₂S is classified Group IIB and is present throughout sour crude processing, hydrodesulfurization units, amine treaters and sour water systems. A tool certified only to IIA cannot be used in areas where H₂S is the representative flammable gas. Verify the specific gases present in your facility against the ATEX certificate before deployment. |
| T4 | Maximum surface temperature class: 135°C — safe for gases with auto-ignition temperature above 135°C |
| X | Special conditions of use documented in the certificate — must be reviewed before deployment |
The Bristle Blaster® Pneumatic: The Only ATEX Zone 1 Certified SP10 Tool
The Bristle Blaster® Pneumatic carries the ATEX marking Ex II 2G c IIA T4 X — certifying it for use in Zone 1 explosive atmospheres. It is currently the only hand-held power tool that combines this ATEX Zone 1 certification with documented capability to achieve surface cleanliness comparable to Sa 2½ (ISO 8501-1) / SSPC-SP 10 and a 65–85 µm Rz anchor profile.
The protection concept is constructional safety (c). The tool achieves the working action — high-velocity wire tip impact — through a mechanism that does not generate ignition-capable sparks. This is an engineering solution, not a procedural restriction: the tool is designed to perform its function in the explosive atmosphere without generating ignition energy.
This combination — Zone 1 certification and SP10 capability — is the reason the Bristle Blaster® Pneumatic is specified by major international operators for their offshore and petrochemical maintenance programmes:
- Offshore platforms: BP, ExxonMobil, Shell, TotalEnergies, Saudi Aramco, Bilfinger Offshore — splash zones, risers, process deck structural steel, flare boom structures
- Refineries and petrochemical plants: BASF, Bayer, DOW Chemical, OMV, Qatargas — in-service maintenance, turnaround work, insulation system repairs
- Pipeline onshore ATEX zones: Field joints and coating repairs in right-of-way zones with gas presence risk — TotalEnergies Bolivia (Planta Incahuasi, 2021), GASNORP Piura, Peru (2021)
- LNG terminals: Structural steel adjacent to cryogenic process equipment, pipe supports, bund area structures
Operational Requirements for Zone 1 Surface Preparation Work
ATEX certification of the tool is necessary but not sufficient. Surface preparation work in Zone 1 requires a complete safe system of work (Permit to Work) that includes:
Permit to Work (PTW) / Cold Work Permit. Zone 1 maintenance work requires a formal hazardous area work permit. The permit defines the work scope, the Zone classification, the required monitoring, the emergency procedures and the authorised personnel. Prepare documentation of the Bristle Blaster® ATEX certificate for inclusion in the PTW package.
Continuous gas monitoring. A calibrated portable gas detector must be worn by the operator throughout the work. The LEL alarm threshold should be set to no higher than 10% LEL — work must stop immediately if the alarm activates. The gas detector itself must be ATEX Zone 1 certified.
Air supply location. The compressed air compressor supplying the Bristle Blaster® Pneumatic must be located outside the Zone 1 boundary — or must itself be ATEX Zone 1 certified. The air supply hose must be routed to avoid damage from vehicle traffic or hot surfaces.
Personal protective equipment (PPE). Minimum requirements for Zone 1 surface preparation work: impact-resistant safety glasses or face shield, hearing protection (the tool generates ~95 dB at the operator’s ear), impact-resistant gloves, anti-static footwear, and fire-resistant coveralls where the site’s hot work policy requires them (standard practice on offshore platforms and LNG terminals).
Authorised supervision. Work in Zone 1 must be supervised by a person authorised for hazardous area work under the facility’s safety management system.
Selecting the Right Configuration for Your Zone 1 Application
| Application | Recommended Model | Key Consideration |
|---|---|---|
| Offshore platform structural steel, topsides maintenance | Bristle Blaster® Pneumatic (ATEX) | Verify compressed air supply routing from outside Zone 1 |
| Refinery process unit — in-service maintenance | Bristle Blaster® Pneumatic (ATEX) | Confirm gas group carefully: IIA covers most saturated hydrocarbons (methane, propane, etc.) but H₂S (hydrogen sulphide) is Group IIB — present in most sour service areas. Confirm T4 (135°C) is sufficient for auto-ignition temperatures of gases present. |
| Pipeline field joint — Zone 1 corridor | Bristle Blaster® Pneumatic (ATEX) | Apply Two-Step Method: Tercoo® disc first pass (same drive unit) if heavy corrosion present, then Bristle Blaster® belt for SP10 finish — approximately 30-second changeover between steps |
| LNG terminal structural steel | Bristle Blaster® Pneumatic (ATEX) | Confirm T4 temperature class is sufficient for cryogenic application (auto-ignition temperatures typically well above 135°C for natural gas) |
| Non-ATEX field maintenance (no explosive atmosphere) | Bristle Blaster® Electric (120V or 240V) | Equivalent surface results without requiring compressed air supply |
For the full step-by-step surface preparation procedure and verification protocol, see our guide on how to achieve SSPC-SP10 without sandblasting. For the full technical specification of SSPC-SP10 and its verification requirements, see our SSPC-SP10 complete technical guide.
Frequently Asked Questions
Is there any abrasive blasting method approved for ATEX Zone 1?
No. There is no abrasive blasting equipment with ATEX Zone 1 certification for surface preparation of steel. The physical mechanism of abrasive blasting — high-velocity particle impact on steel — generates thermite sparks that are incompatible with Zone 1 operation. Any claim of a “spark-free blasting method” approved for Zone 1 should be verified against an actual ATEX certificate before reliance.
What is the difference between ATEX Zone 1 and NEC Class I Division 1 (US)?
NEC Class I Division 1 does not map exactly to IEC Zone 1. The correct equivalence is: Division 1 corresponds to IEC Zone 0 + Zone 1 combined; Division 2 corresponds to Zone 2. Equipment certified only for Zone 1 (Category 2G) may not be acceptable for all Division 1 locations, since Division 1 legally includes Zone 0 areas — which require Category 1G (Zone 0) equipment. Always verify with the facility’s hazardous area classification documents. The NEC Division system was the traditional US classification; NEC Article 505 introduced the Zone classification (Zone 0, 1, 2) to align with IEC 60079. For facilities operating under Article 505, Zone 1-certified equipment is accepted in Zone 1-designated areas. ATEX Zone 1 certification is recognised by all major international operators under both systems.
Do I need a different tool for ATEX Zone 2?
A tool certified for Zone 1 (Category 2G) may also be used in Zone 2. Zone 1 certification covers both Zone 1 and Zone 2 applications. The Bristle Blaster® Pneumatic (Ex II 2G c IIA T4 X) is therefore approved for both Zone 1 and Zone 2 surface preparation.
What documentation should I have on site when using the Bristle Blaster® Pneumatic in Zone 1?
You should have access to: the ATEX certificate for the specific tool serial number (obtainable from MontiPower), the tool’s operating manual (which contains the conditions of use for the X marking), and the facility’s Permit to Work documentation for hazardous area maintenance. Contact our technical team for the current certificate and conditions of use documentation for your specific tool configuration.
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