Safety Critical Engineering

Engineering for
Hazardous Environments
Where Failure Is Not an Option

Mikronexis designs and develops embedded systems for safety-critical and explosive atmosphere environments. Every product we build is engineered to meet recognised international standards — so your system is certifiable, fail-safe, and production-ready.

EN 50271 Compliant
IEC 60079 Series
Fail-Safe Architecture
Evidence-Based Validation
EN 50271
IEC 60079
Fail-Safe
Validated

What Is Safety Critical Engineering?

A safety-critical system is one where failure could result in loss of life, serious injury, significant environmental damage, or destruction of high-value assets.

Unlike conventional embedded development, safety-critical engineering operates under a strict framework of standards, design disciplines, and documentation requirements. Every architectural decision must be justified, every failure mode analysed, and every line of firmware verified against the system's safety requirements. The goal is not just a working product — it is a certifiable product.

Systematic Failure Prevention

Safety engineering uses structured methodologies — FMEA, HAZOP, fault tree analysis — to identify and eliminate failure modes before they reach the field.

Standards Compliance as Mandatory

Products deployed in hazardous environments must comply with specific international standards to achieve regulatory approval and market access.

Evidence-Based Validation

Every safety claim must be backed by documented evidence — test records, analysis reports, design justifications — forming a complete safety case.

Consequence of Failure by Domain
Explosive Atmosphere (IEC 60079) Catastrophic
Gas Detection (EN 50271) Critical
Industrial Monitoring Significant
Consumer Devices Moderate
Why this matters: Products operating in the top two domains require formal safety engineering, standards compliance, and documented evidence before regulatory approval. Without it, the product cannot legally be placed on the market in those environments.

The Standards We Work To

Our engineering practices are aligned with the international standards that define safety requirements for gas detection instruments and explosive atmosphere equipment.

European Standard
EN 50271
Electrical apparatus for the detection and measurement of combustible gases, toxic gases or oxygen — Requirements and tests for apparatus using software and/or digital technologies
Gas Detection Software

EN 50271 governs the software and digital design requirements for gas detection instruments. It mandates a disciplined software development lifecycle — from requirements through design, implementation, and testing — with full traceability and documentation at every stage. Compliance ensures that the detection software performs reliably under all foreseeable operational conditions and failure scenarios.

Software Requirements Specification

Formal definition of all software functions, safety functions, and their constraints — the foundation of the safety case.

Software Architecture & Design

Structured design with clear module separation, defined interfaces, and explicit handling of safety-relevant functions.

Software Verification & Validation

Systematic testing including unit tests, integration tests, and functional safety tests against all defined requirements.

Failure Mode Analysis (FMEA)

Systematic identification of all software failure modes and their effects on the overall system safety.

Full Documentation Package

Complete technical file: plans, specifications, design documents, test records, and safety assessment evidence.

Change Management & Maintenance

Controlled processes for software updates, version management, and re-validation after any change affecting safety functions.

International Standard Series
IEC 60079 Series
Explosive Atmospheres — Equipment design, testing, and certification for use in areas where flammable gases, vapours, or dusts may be present
Explosive Atmospheres

The IEC 60079 series is the internationally recognised framework for designing electrical and electronic equipment intended for use in explosive atmospheres — environments where flammable gases, vapours, mists, or combustible dusts may be present. The series covers multiple protection concepts, each suited to different hazard classifications and operational requirements. Compliance is mandatory for equipment deployed in classified hazardous areas.

IEC 60079-0 — General Requirements

Foundational requirements applicable to all Ex equipment: construction, testing, and marking for explosive atmosphere use.

IEC 60079-1 — Ex d Flameproof Enclosures

Flameproof enclosure design where any internal ignition cannot propagate to the surrounding explosive atmosphere.

IEC 60079-11 — Ex i Intrinsic Safety

Intrinsically safe circuits that limit electrical energy below levels capable of igniting the surrounding hazardous atmosphere.

Hazardous Area Zone Classification

Zone 0/1/2 (gases) and Zone 20/21/22 (dusts) — appropriate protection concept selection based on area classification.

Temperature Class & Ignition Assessment

Maximum surface temperature analysis against the ignition temperature of the specific flammable substance in the hazardous area.

ATEX / IECEx Certification Pathway

Guidance through ATEX (EU) and IECEx (international) certification processes with notified body coordination.

Our Safety Engineering Process

A structured, evidence-driven process designed specifically for safety-critical embedded development — not adapted from conventional software practice.

01

Hazard & Risk Analysis

We begin with a structured hazard identification — HAZOP, FMEA, or preliminary hazard analysis — to define the safety requirements the system must meet.

Hazard register
Risk assessment report
Safety requirements baseline
02

Safety Requirements Specification

Every safety function is formally specified — what it must do, under what conditions, with what response time, and how failure must be handled.

Software requirements spec (SRS)
Safety functions list
Traceability matrix
03

Safety-Oriented Architecture

System and software architecture is designed with explicit fail-safe behaviour, redundancy where required, watchdog strategies, and hardware/software separation of safety functions.

System architecture document
Fail-safe strategy definition
Interface control document
04

Compliant Firmware Development

Firmware is written to EN 50271 software development requirements — structured coding, defensive programming, runtime monitoring, and systematic error handling throughout.

Reviewed, traceable source code
Static analysis reports
Code review records
05

Verification & Validation

All safety functions are independently verified through structured testing — unit, integration, and system level — with full coverage evidence against every safety requirement.

Test plan & specifications
Test execution records
Requirements coverage report
06

Safety Case & Technical File

We compile the complete safety case — all design evidence, analysis, test records, and compliance justifications — ready for regulatory submission or third-party audit.

Safety case document
Complete technical file
Certification-ready package

Where Safety Critical Engineering Is Mandatory

These sectors operate under strict regulatory frameworks where non-compliant products cannot legally be deployed.

Gas Detection

Fixed and portable instruments for combustible, toxic, and oxygen-deficiency monitoring in industrial and field environments.

EN 50271 IEC 60079

Oil & Gas

Control, sensing, and monitoring equipment for upstream, midstream, and downstream environments classified as Zone 1 or Zone 2.

IEC 60079 ATEX

Mining

Underground gas monitoring, personnel safety devices, and communication systems designed for methane and dust-hazard environments.

IEC 60079 EN 50271

Industrial & Manufacturing

Process control, safety instrumented systems, and condition monitoring in chemical plants, water treatment, and heavy industry.

IEC 61511 EN 50271

Healthcare & Life Sciences

Medical gas monitoring, environmental safety systems, and embedded diagnostics where patient safety is directly dependent on sensor integrity.

IEC 60601 EN 50271

Safety Critical Engineering in Practice

A delivered project that demonstrates our safety-aligned embedded development capability.

Completed Project
Industrial Gas Monitor

A portable industrial gas detection device capable of monitoring multiple hazardous gases simultaneously with real-time threshold alerts, audible/visual alarms, data logging, and a ruggedised enclosure for field deployment. Designed with EN 50271 software requirements in mind throughout development.

STM32 C Firmware MQ Sensors OLED Display PCB Design EN 50271 Fail-Safe Design
Multi-gas detection with audible & visual alarm under 2-second response time
Fail-safe firmware architecture with hardware watchdog and redundant sensor validation
Full requirements traceability and test evidence documentation delivered to client
Gas Monitor — MKN-GM1
Industrial Portable · Multi-Gas Detection
0.2%
LEL CH₄
19.8%
O₂ Level
12ppm
CO — WARN
1ppm
H₂S
System Operational — Monitoring Active

Frequently Asked Questions

Answers to the most common technical and commercial questions about safety critical embedded development.

If your product is an electrical apparatus for the detection and measurement of combustible gases, toxic gases, or oxygen — and you intend to place it on the EU market — then yes, EN 50271 compliance is mandatory. It is a harmonised standard under the ATEX Directive (2014/34/EU) and the relevant EU product safety framework. Non-compliant products cannot legally be sold or deployed in EU member states for these applications. Outside the EU, EN 50271 is widely recognised as the de-facto benchmark globally.
IEC 60079 dictates how your hardware must be designed and constructed to be safe for use in explosive atmospheres. The specific sub-standard you need depends on the protection concept chosen — for example, Ex d (flameproof enclosure, IEC 60079-1) means your enclosure must contain any internal ignition source; Ex i (intrinsic safety, IEC 60079-11) means your circuit must limit energy below ignition thresholds. The choice is driven by your hazardous area classification (Zone 0/1/2) and operational requirements. We help you select the right protection concept early in the design process to avoid costly rework later.
We cover the engineering side of the certification pathway — compliant design, required documentation, evidence packages, and technical file preparation. The formal certification assessment itself is conducted by an accredited notified body (such as SGS Baseefa, Bureau Veritas, or Intertek) — a regulatory requirement we cannot replace. However, we will coordinate with your chosen notified body, respond to technical queries, and ensure your submission is complete and correct before it reaches them. This significantly reduces the number of audit cycles and accelerates time to certification.
Yes. This is a common engagement. We begin with a compliance gap assessment — reviewing your existing firmware, hardware design, and documentation against the applicable standard requirements. We then deliver a gap report with a prioritised remediation roadmap. Depending on the gaps found, remediation may involve targeted firmware changes, additional test coverage, documentation creation, or in some cases architectural changes to specific safety functions. Gap assessments typically take 2–4 weeks and give you a clear picture of the effort required before committing to a full remediation programme.
Timelines depend heavily on project complexity and starting point. A new safety-critical product from concept to certification-ready technical file typically ranges from 9 to 18 months — significantly longer than a conventional embedded project of equivalent functional complexity. This overhead is driven by the required documentation, structured design reviews, formal test campaigns, and notified body interaction. Starting with a strong requirements definition and choosing the right protection concept early are the two biggest factors in keeping a project on schedule. We provide detailed project plans at the start of each engagement so timelines are clearly understood.

Let's Engineer Your Safety Critical Product

Whether you're starting from scratch, need a compliance gap assessment, or are preparing an existing product for certification — we're ready to help you navigate the technical and regulatory path forward.

EN 50271 Compliant Development
IEC 60079 Series Design
Gap Assessment Available
Certification-Ready Documentation