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ATEX Intrinsically Safe Radios: DSEAR and TIA-4950

How to select safe, compliant two-way radios for hazardous areas 

Where flammable gases, vapours, mists or combustible dusts may be present, radio equipment must be selected and controlled, so it does not introduce a foreseeable ignition source within its certified conditions of use. 

Affini helps organisations translate hazardous-area classifications and operational communications requirements into controlled radio solutions, including certified handsets, approved batteries and accessories, RF coverage design, deployment support and lifecycle management. 

Example: front, side and rear views of an ATEX-certified portable radio. Product selection must follow the applicable certificate and approved accessory schedule.

What is an intrinsically safe radio?

An intrinsically safe radio is designed to limit electrical and thermal energy, so the equipment does not ignite the specified hazardous atmosphere under the normal and fault conditions covered by its certification.

  • Radio handset 
  • Battery 
  • Antenna 
  • Audio accessory 
  • Carry accessory 
  • Other connected equipment 

What is ATEX?

ATEX is the commonly used name for the European framework covering workplaces and equipment where explosive atmospheres may occur. It comprises the ATEX Workplace Directive 1999/92/EC, which sets minimum requirements for protecting workers, and the ATEX Equipment Directive 2014/34/EU, which covers equipment and protective systems intended for use in potentially explosive atmospheres.

Area Requirement
Great Britain workplace duties Implemented principally through the Dangerous Substances and Explosive Atmospheres Regulations 2002.
Great Britain product requirements Implemented through the Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 2016, as amended.
Northern Ireland A distinct product conformity regime applies; verify the marking and conformity-assessment route for the intended market and date of supply.

How does ATEX relate to DSEAR?

DSEAR requires employers and the self-employed to protect people from safety risks arising from dangerous substances. Relevant duties include identifying dangerous substances; assessing fire and explosion risks; eliminating or controlling those risks; mitigating consequences; preparing emergency arrangements; providing information, instruction and training; classifying places where explosive atmospheres may occur; and avoiding ignition sources within classified areas.

DSEAR is a workplace risk-management regime. ATEX product certification provides evidence that equipment has been assessed for stated hazardous-area conditions. Neither should be treated as a substitute for the other.

An ATEX marking does not, by itself, make a radio suitable for every hazardous area. The duty holder must match the complete equipment marking, certificate, conditions of use and approved accessory configuration to the site’s DSEAR assessment.

ATEX vs TIA-4950: what is the difference?

ATEX and IECEx context TIA-4950 context
Commonly expressed using hazardous-area zones and IEC 60079 protection concepts. TIA-4950-C is a North American standard for battery-powered portable land-mobile-radio equipment intended for specified hazardous classified locations.
Markings may include equipment group, category, protection concept, gas or dust group, temperature class and equipment protection level. Product approvals commonly identify the relevant Class, Division and Group, or stated Zone classification.
In Great Britain, product conformity sits alongside the duty holder’s DSEAR assessment. A UL listing to TIA-4950 is not ATEX certification and should not be described as such.
Suitability must be established from the exact certificate, marking, conditions of use and approved accessories. Suitability must be established from the exact listing, classification, labelled configuration and operating instructions.

Why the ATEX and TIA-4950 distinction matters

A TIA-4950-listed radio must not be assumed to be equivalent to an ATEX-certified radio merely because both may be described as “intrinsically safe”.

Motorola MOTOTRBO R7 hazardous-location configuration Listed by UL to ANSI/TIA-4950-B and specified Canadian standards for defined Class and Division locations. Motorola states that it must be factory ordered with the intrinsic-safety option, carry the hazardous-location label and use the listed battery and accessories.
Motorola MOTOTRBO R7Ex A separately designed radio carrying ATEX and IECEx certification with different hazardous-area markings.

A hazardous-location option on one product version does not make every radio bearing the same family name ATEX certified. The exact model, factory option, certification label, battery and approved accessories must be checked. For a UK application, the duty holder should also confirm compliance with the applicable product regime and suitability for the hazardous-area classification identified through the DSEAR assessment.

Understanding hazardous-area zones

Gas, vapour and mist zones

Zones describe how often, and for how long, an explosive atmosphere is expected to be present. A competent person should determine the applicable classification as part of the site risk assessment.

Zone definitions

Atmosphere Zone General description
Gas, vapour or mist 0 Present continuously, for long periods or frequently.
Gas, vapour or mist 1 Likely to occur occasionally during normal operation.
Gas, vapour or mist 2 Not likely during normal operation or, if it occurs, present only briefly.
Combustible dust 20 Present continuously, for long periods or frequently.
Combustible dust 21 Likely to occur occasionally during normal operation.
Combustible dust 22 Not likely during normal operation or, if it occurs, present only briefly.

Selection goes beyond the zone

The applicable substance group, temperature requirement, ambient conditions, environmental protection and certificate conditions must also be considered.

How to read an ATEX radio marking

Typical gas marking: II 2G Ex ib IIC T4 Gb

Why ATEX radios matter

II Equipment group for surface industries other than mines susceptible to firedamp.
2G Category 2 equipment for gas, vapour or mist applications.
Ex Explosion-protected equipment.
ib Intrinsic-safety protection level “ib”.
IIC Gas group IIC.
T4 Temperature class indicating a maximum surface temperature of 135°C under the applicable certification conditions.
Gb Equipment protection level for gas atmospheres.

Always verify the current certificate and manufacturer’s instructions. A product name, blue housing or generic “IS” description is not proof that a particular configuration is suitable for a specific hazardous area.

Risks of unsuitable radio equipment

Using unsuitable equipment within a classified hazardous area may create significant safety, legal and operational exposure.

  • Ignition risk: an unsuitable radio, battery or accessory may introduce spark energy, hot surfaces or another potential ignition source.
  • Loss of certified protection: unapproved accessories, modification, damage or incorrect repair may invalidate the certified configuration.
  • Regulatory exposure: inadequate assessment or control of explosion risk may lead to enforcement action and, depending on the circumstances, prosecution.
  • Operational disruption: equipment may require withdrawal, investigation, repair or replacement, interrupting critical operations.
  • Civil, insurance and reputational consequences: equipment selection and supporting evidence may be scrutinised following an incident.

How to select an intrinsically safe radio

A defensible specification should identify the hazardous-area zones; whether the hazard is gas, vapour, mist, combustible dust or a combination; the applicable gas or dust group; the temperature class or maximum surface-temperature requirement; ambient and environmental conditions; the approved handset, battery, antenna and accessory combination; any special conditions of use; configuration-control arrangements; the required RF band and coverage; and the applicable product conformity route.

The industry sector alone does not determine the required certification. Hazardous-area communications may be relevant in oil and gas, petrochemical processing, fuel operations, utilities, water treatment, pharmaceutical manufacturing, defense, fire and rescue, and locations with combustible-dust hazards, but the requirement depends on the actual substance, work activity and hazardous-area classification.

Talk to Affini about hazardous-area radio communications
Affini can help organisations define and deploy controlled radio solutions for hazardous environments, including requirements review, interpretation of hazardous-area classifications, selection of certified radios and accessories, RF coverage design, configuration and asset control, user guidance, deployment support, inspection, maintenance and lifecycle services.
Final equipment suitability remains dependent on the customer’s DSEAR assessment and hazardous area classification. Affini does not replace the duty holder or the competent person responsible for hazardous-area assessment.

Verified sources and legal note

Additional verified source: Telecommunications Industry Association, TIA-4950-C, Requirements for Battery-Powered, Portable Land Mobile Radio Applications in Class I, II, and III, Division 1, Hazardous Classified Locations.

This page provides general technical and marketing information. It is not legal advice, hazardous-area classification advice or a substitute for competent engineering assessment. Product approvals, markings, certificates, special conditions of use and regulatory routes should be checked against current official documentation at the point of specification and supply.