NR-4 – Specialized Services in Occupational Health and Safety (SESMT)

NR-4 originally issued by Ordinance MTb No. 3.214 on June 8, 1978, under the title “Specialized Service in Safety and Occupational Medicine – SSMT,” mandates the hiring of occupational safety and health professionals based on the company’s employee count and risk level. These professionals, comprising SESMT, are tasked with applying safety engineering and occupational medicine in work environments.

NR-4 has undergone significant changes, including a comprehensive revision in 1983, updating its title to “Specialized Services in Occupational Health and Safety – SESMT.” From 1983 to 2013, twelve updates were made, including changes to qualification requirements and the introduction of a Professional Identification Card for Occupational Safety Technicians.

In 2007, a provision for allowing shared services among companies has been added. Subsequent amendments in 2014 linked SESMT professional training and registration to respective Professional Councils and permitted hiring more than one full-time occupational physician. Another 2014 update required SESMT professionals to record monthly data on work accidents and occupational diseases.

The most recent amendment in 2016 addressed companies classified under Risk Level 1 establishing single engineering and medicine services. NR-4’s modernization is currently being discussed tripartitely following changes to the CLT through Law No. 13.467, of July 13, 2017. The CTPP, responsible for NR-4 updates, was re-established in 2019 by Decree No. 9.944 after its dissolution earlier that year.

NR-4 – Specialized Services in Occupational Health and Safety
(MTP Ordinance No. 4219 of December 20, 2022)

Annex I – National Classification of Economic Activities (CNAE) Version 2.0, with Corresponding Risk Level

Annex II – Dimensioning of SESMT

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