Ex certification: what it is and what it ensures
What an explosive atmosphere is, what Ex certification ensures, why ordinary equipment stays out of hazardous areas, and what changes for OHS management.
PHYGITALL team · Engineering and product
August 26, 2026 · 3 min read
In a refinery, a fuel terminal, or a grain processing facility, the air isn’t always just air. Flammable gases, vapors, and combustible dust mix with it and create zones where a single ignition source is enough to set off an explosion. Ex certification exists so that equipment can operate safely in these environments.
What is an explosive atmosphere?
An explosive atmosphere is a mixture of air and flammable substances, such as gases, vapors, or dusts, in a concentration that can ignite. The places where this mixture can occur are mapped and designated as hazardous areas, also called classified areas. These are defined zones of the plant where an explosive atmosphere is present continuously or frequently, or may form under abnormal operating conditions.
This mapping matters because it affects everything that enters the area: tools, electrical installations, vehicles, and any electronic device must be suitable for the risk in that zone.
What Ex certification ensures
Ex certification confirms that a piece of equipment has been designed, tested, and approved to operate in an explosive atmosphere without becoming an ignition source. In practice, the process looks at factors such as the circuit design, the energy the circuit stores and releases, surface temperatures, the enclosure, and the battery.
In Brazil, accredited organizations issue certification for explosive atmospheres under INMETRO (Brazil’s certification body). Equipment that communicates by radio, as IoT devices do, also goes through type approval by ANATEL (Brazil’s telecom regulator). The two processes are separate and complementary: one deals with ignition risk, the other with radio compliance.
Unlike a generic quality seal or a manufacturer’s declaration, Ex certification is the result of third-party testing with a defined scope, and it has to be maintained throughout the equipment’s service life. Repairs, battery replacements, and design changes are subject to specific rules so that the Ex rating remains valid.
Why ordinary equipment stays out of hazardous areas
An ordinary smartphone has exposed electrical contacts, components that heat up during use, and a battery with enough energy to create a spark if it is damaged. None of that is a problem in an office. Inside a hazardous area, every one of those is a potential ignition source.
That is why the rule is strict: equipment without an Ex rating stays outside. Brazil’s NR safety standards (NRs) covering flammables and electrical installations require everything that operates in these zones to be suitable for the area’s classification, and the requirement extends from the electrical panel to the simplest electronic device.
What changes for OHS management
For years, the practical consequence of this rule was a gap: in the very areas with the highest risk, workers remained cut off from the control room. The phone stayed outside, the radio didn’t always go in, and emergency response depended on procedures and on whoever happened to be nearby.
Ex certification for connected worker devices closes that gap. The Smartbadge with Ex certification was Brazil’s first Ex-rated smart badge, and it brings into the hazardous area what used to stop at its perimeter: real-time location, an emergency button, and auditable evidence of presence and response.
For occupational health and safety (OHS) management, the result is operational visibility across the entire plant, including the highest-risk zones. The time between an emergency call and the arrival of help gets shorter, field records become auditable evidence that also supports investigations, and protection no longer stops at the boundary of the hazardous area.
The question that opens every conversation
When you evaluate technology for a hazardous area, the first question is always the same: does the equipment have valid Ex certification for the zone where it will operate? Without that answer, the rest of the conversation doesn’t start. With it, the highest-risk area of the plant is no longer the least protected one.
PHYGITALL team
Written by the engineering and product team at PHYGITALL, a Brazilian industrial IoT and connected worker company.
Frequently asked questions
What is Ex certification?
Ex certification confirms that a piece of equipment can operate in explosive atmospheres without becoming an ignition source. In Brazil, it is issued under INMETRO (Brazil's certification body), and equipment that communicates by radio also needs type approval from ANATEL (Brazil's telecom regulator).
Does all electronic equipment need Ex certification?
No. The requirement applies to equipment that operates in hazardous areas, the zones of a plant where an explosive atmosphere may be present. Outside those zones, the certification is not mandatory.
Is there a smart badge certified for hazardous areas?
Yes. PHYGITALL's Smartbadge with Ex certification was Brazil's first Ex-rated smart badge, built to operate in explosive atmospheres with real-time location and an emergency button.