NR-10 and INMETRO Certification for Explosive Atmospheres in Brazil
Overview
Brazil has its own regulatory framework for explosion-proof equipment, separate from but aligned with European ATEX and international IECEx standards. Two key regulations govern Ex equipment in Brazil:
- NR-10 — the electrical safety regulation issued by Brazil's Ministry of Labor
- INMETRO — the national certification body that certifies Ex equipment for the Brazilian market
Understanding both is essential for any company operating in Brazil's oil & gas, petrochemical, mining, or chemical industries.
What Is NR-10?
NR-10 (Norma Regulamentadora No. 10) is Brazil's mandatory regulation for safety in electrical installations and services. It covers:
- General electrical safety — design, construction, maintenance, and operation of electrical installations
- Hazardous area requirements — classification of areas with explosive atmospheres and the equipment permitted in each zone
- Worker qualifications — training and certification requirements for personnel working with electrical installations in hazardous areas
NR-10 applies to all workplaces in Brazil and is enforced by the Ministry of Labor through workplace inspections. Non-compliance can result in fines, facility shutdowns, and criminal liability.
NR-10 and Zone Classification
NR-10 follows the IEC zone classification system:
| Zone | Gas/Vapor | Dust |
|---|---|---|
| Zone 0 / 20 | Explosive atmosphere present continuously | Combustible dust cloud present continuously |
| Zone 1 / 21 | Explosive atmosphere likely during normal operation | Dust cloud likely during normal operation |
| Zone 2 / 22 | Explosive atmosphere only in abnormal conditions | Dust cloud only in abnormal conditions |
This is the same classification used by ATEX and IECEx, making the technical requirements compatible.
INMETRO Certification
INMETRO (Instituto Nacional de Metrologia, Qualidade e Tecnologia) is Brazil's national standards and certification body. Under Portaria INMETRO No. 179/2010, all equipment intended for use in explosive atmospheres in Brazil must carry INMETRO certification.
Key Requirements
- Mandatory third-party certification — self-declaration is not accepted. Equipment must be tested and certified by an INMETRO-accredited Conformity Assessment Body (OCP)
- INMETRO mark required — the product must carry the INMETRO mark plus the mark of the accredited OCP
- Factory audit — the manufacturer's quality system must be audited as part of the certification process
- Certificate renewal — INMETRO certificates must be maintained through periodic surveillance audits
Accredited Certification Bodies for Ex Equipment
Several international certification bodies are accredited by INMETRO for Ex equipment:
- CEPEL — Eletrobras research center, historically the main Brazilian Ex testing lab
- DNV — accredited for INMETRO Ex certification
- TÜV Rheinland — offers INMETRO certification services
- Bureau Veritas — accredited OCP for INMETRO
INMETRO vs ATEX vs IECEx
| Aspect | ATEX | IECEx | INMETRO |
|---|---|---|---|
| Region | European Union | International | Brazil |
| Legal basis | EU Directive 2014/34/EU | IEC 60079 series | Portaria INMETRO 179/2010 |
| Mandatory? | Yes (in EU) | Voluntary (but widely accepted) | Yes (in Brazil) |
| Factory audit | Yes | Yes | Yes |
| Certificate renewal | Indefinite (if no design change) | 5 years | Periodic surveillance |
| Mutual recognition | — | Yes (IECEx members) | Accepts IECEx test reports |
Can You Use ATEX/IECEx Equipment in Brazil?
Not directly. ATEX or IECEx certification alone is not sufficient for the Brazilian market. However:
- IECEx test reports are accepted — INMETRO accepts test reports from IECEx-accredited labs, which significantly reduces the time and cost of obtaining INMETRO certification
- ATEX certificates are not directly recognized — but the underlying IEC standards are the same, so the technical testing overlap is high
- A separate INMETRO certificate is always required — even if the product already holds ATEX and IECEx certification
This means a manufacturer with existing IECEx certification can obtain INMETRO certification faster, but the INMETRO process itself is mandatory and cannot be skipped.
Petrobras Requirements
Petrobras (Petróleo Brasileiro S.A.) is Brazil's state-controlled oil company and the country's largest petroleum operator. Petrobras has its own technical standards that supplement NR-10 and INMETRO:
- N-2154 — Petrobras standard for electrical installations in classified areas
- All contractors and suppliers must provide equipment with valid INMETRO certification
- Petrobras audits equipment certification as part of vendor qualification
- Offshore platforms follow the most stringent Zone 1 requirements for most operational areas
For companies supplying Ex equipment to Petrobras operations (including subcontractors), INMETRO certification is non-negotiable.
Practical Guidance for Procurement
When procuring explosion-proof equipment for use in Brazil:
- Verify INMETRO certification — ask the manufacturer for the INMETRO certificate number and the accredited OCP mark
- Check certificate validity — INMETRO certificates require periodic renewal through surveillance audits
- Don't assume ATEX = Brazil compliance — ATEX certification is a good starting point but does not replace INMETRO
- IECEx helps — if a product has IECEx certification, the path to INMETRO is shorter
- Plan for lead time — INMETRO certification can take 3–12 months depending on whether IECEx test reports are available
- NR-10 training — personnel operating Ex equipment in Brazil must have NR-10 qualification
Related Standards
- ABNT NBR IEC 60079 — Brazilian adoption of the IEC 60079 series (explosion protection standards)
- ABNT NBR 5418 — Electrical installations in explosive atmospheres
- NR-20 — Safety and health with flammable liquids and fuels (complements NR-10)
- NR-33 — Safety for work in confined spaces (often overlaps with Ex classified areas)