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Thorne & Derrick Guest Post – ATEX compliant heaters in the defence industry

DSEAR and DSEAR Compliant Heaters

DSEAR stands for the Dangerous Substances and Explosive Atmospheres Regulations 2002.

Dangerous substances put peoples’ safety at risk from fire, explosion and corrosion of metal. DSEAR puts duties on employers to protect people from these risks and ensure their safety in the workplace, and to members of the public who may be put at risk by work activity. THE HSE usually recommends that DSEAR is updated every 3-5 years dependent upon the risk levels of the operations.

Compliance with DSEAR encompasses many facets of business activity including:

  • Risk assessment of plant operations
  • Defining of any hazardous zones together

Installation of hazard compliant equipment and preparation of explosion protection records

According to the HSE fires and explosions are one of the main causes of deaths and damage in vehicle repair operations where the workspace has been designated as a potentially explosive atmosphere – this is according to UK DSEAR regulations and the European ATEX Directive.

Usually, the potential risk of explosion involves the mishandling of petrol eg when draining fuel tanks and lines, but incidents have also occurred during ‘hot work’ repairs on vehicle diesel tanks and waste oil storage tanks, during the inappropriate use of paints, thinners or waste petrol to ignite rubbish fires and the use of waste engine oil in space heaters.

Similarly, there is an explosion risk in aircraft hangars during maintenance operations in the modern passenger and cargo aircraft sectors as well as the defence industry.

Project Application | Specification & Supply of ATEX Compliant Heaters

Thorne & Derrick, The Experts in Equipment for Explosive Atmospheres, working in partnership with the MoD appointed M&E Design Consultancy have supplied ATEX Compliant Heaters to satisfy the Heating Clauses of their specification requirement to provide heaters suitable for installation in a Zone 2 hazardous area with Temperature Class 3 and IIB explosive gas atmospheres.

The project at a Royal Naval Air Station (RNAS) facility in the UK benefitted from the supply and installation of the LFH next-generation of ATEX & IECEx certified electric fan heaters for explosive atmospheres.

Manufactured by EXHEAT, a globally renowned manufacturer of electric process heating and control systems, the LFH model of Fixed Fan Heater combines superior efficiency with simple functionality to provide a ATEX Compliant heating solution for use in hazardous environments where the explosive atmosphere is classified as Zone 1/2 (IIB+H2).

Design, Specify, Supply – DSEAR Compliant Heaters

Thorne & Derrick provided experienced design assistance to the Mechanical and Electrical Engineering contractor and design consultant for the selection of hazardous area space heaters to a new vehicle inspection and maintenance bay that was being constructed.

Thorne & Derrick were originally requested to submit a tender for Ex rated infrared heaters which had been specified at early design stage.

Thorne & Derrick Technical Sales Engineer reviewed the heating application, calculated heat losses and made a recommendation – due to the large open area the infra red heaters would have normally been selected to provide comfort heating for people working in the area. However, due to the hazardous area classification, gas group and T-class, T&D advised that the infra red heaters specified would not be compliant and pose a significant health and safety risk. From our large portfolio of ATEX certified heaters, T&D recommended the LFH heater based on its unrivalled air flow, temperature rise capability and compliance with the explosive atmosphere classification.

This was accepted by both the design consultant and M&E contractor.

T&D also offered advice to design consultant on possible use of ATEX high speed doors in the maintenance bay.

T&D advised that using high speed doors would help to reduce the overall heat loss and subsequent KW rating of any ATEX space heaters and therefore a reduction in energy consumption/costs.





EXHEAT LFH Fan Heater combines superior electrical heating efficiency with simple functionality to provide a next-generation heating solution for use in hazardous area environments where the explosive atmosphere is classified as Zone 1/2 (IIB+H2) according to the ATEX Directive.

Certified to the new EN 80079-36 and EN 80079-37 standards for constructional safety, the EXHEAT LFH is supplied ready to ‘plug and play’, with the option of fitting a plug, or hard wiring to an isolator unit.

Incorporating a stainless steel casing for added toughness and durability, the LFH electric fan heater manufactured by EXHEAT is designed to operate in ambient temperatures of -40°C to +40°C, and uses a framework allowing for multiple mounting options on floors, walls and even ceilings in explosive atmospheres.

Depending on the heater model selected, inlet air temperatures can be increased by up to 46°C. Heaters are available up to 40kW output and provide class leading, energy efficient heating solutions for both onshore and offshore applications.

Portable & Temporary Heating Solution for Explosive Atmospheres

The EXHEAT LFH can also be manufactured and supplied as a portable configuration with options for anti-static castors, lifting handles, built in isolator and controls if required. The portable version can also be ducted front and rear to provide a versatile and portable heating solution for hazardous area locations. 


Thorne & Derrick are leaders in the development and distribution of Product Innovations that deliver significant improvements to clients plant, people and operational safety in the explosive atmosphere industries.

Thorne & Derrick service UK and international businesses working on underground cables, overhead lines, substations and electrical construction at LV MV HV & EHV – we distribute the most extensive range of Cable Installation & Electrical Distribution Equipment to the Power Transmission & Distribution industry in the onshore and offshore wind, solar, rail, oil/gas, data centre, battery storage and utility sectors.

Your first-choice provider of innovative and competitive solutions to ensure ATEX & IECEx Compliance for Hazardous Area Electrical, HVAC & Process Instrumentation Equipment to UK and international projects.

Control Panels | Plugs | Isolators | Enclosures & Junction Boxes | Lighting | Control Stations | Motor Starters | Trace Heating | Gas Detection | Flame Detection | Process Instrumentation | Process Heating | Ventilation Fans | Security Access Control

Sigma-HSE can undertake DSEAR Assessments and Hazardous Area Classification (HAC) for your business. To learn more about DSEAR Risk Assessments, you can read our blog here. 

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