Technical reference · Updated in September 2026

NR-20: flammable liquids and fuels in quick reference

What the standard requires of anyone storing and handling fuel — from the farm diesel tank to the containment basin, the installation classes and training. With the item number next to each requirement.

Brasil Sustentabilidade
NR-20 quick referenceBrasil Sustentabilidade
≤ 60 °Cflash point: defines a flammable liquid
I · II · IIIinstallation classes
6types of training
60/2025MTE Ordinance in force

Search by item number — 20.14.4 — or by word: containment basin, diesel, flash point.

0Every number of NR-20 on one page

If you only take one sheet to the field, take this one

WhatFigureItem
Flammable liquidflash point ≤ 60 °C20.3.1
Combustible liquidflash point > 60 °C and ≤ 93 °C20.3.3
Tank of flammable or combustible liquidleak containment system (basin) mandatory20.14.4
Inside the containment basinstoring materials and containers is prohibited, except for maintenance and inspection20.14.4.1
Small installation (gas 1–2 t; liquids 1–10 m³)not classified; records attached to the risk management programmeAnnex II, 1
Training at such a small installationat least 3 workers on the Basic CourseAnnex II, 1.1
Diesel or biodiesel tank inside a buildingburied only; above ground solely for an emergency generatorAnnex III, 1 and 2
Tank limit inside a building5,000 L per tank and room; 10,000 L per buildingAnnex III, 2.1 “d”
Introductory Course3 hAnnex I
Basic Course4 h (Class I), 6 h (II), 8 h (III)Annex I, Table 1
Intermediate Course12 h (I), 14 h (II), 16 h (III)Annex I, Table 1
Refresher training4 h; frequency by course and class20.12.9 · Table 2
Reporting a serious incidentby the 2nd working day20.16.1.1
Emergency drillat least once a year20.15.5

1Where NR-20 comes into the farm

This is where NR-31 sends fuel storage

NR-31 does not regulate fuel storage: it refers expressly to NR-20 (items 31.2.1.1, “f”, and 31.3.5, “f”). The farm diesel tank, the containment basin and training for anyone handling flammables are based here — and, as a technical reference, on ABNT NBR 17505.

Who it applies to (20.2)

NR-20 applies to the extraction, production, storage, transfer, handling and manipulation of flammables and combustible liquids. It does not apply to single-family residential buildings (20.2.2, “b”), nor to offshore oil and gas platforms and support installations (NR-37).

The three installation classes (20.4, Table 1)

ClassBy activityFlammable gasesFlammable and/or combustible liquids
Iservice stations; piped gas distribution with maximum allowable working pressure up to 18.0 kgf/cm²over 2 t up to 60 tover 10 m³ up to 5,000 m³
IIbottling plants; pipeline transport; piped distribution with maximum allowable working pressure above 18.0 kgf/cm²over 60 t up to 600 tover 5,000 m³ up to 50,000 m³
IIIrefineries; natural gas processing; petrochemicals; ethanol plantsover 600 tover 50,000 m³

The type of activity takes precedence over capacity (20.4.1.1) — except above 250,000 m³ of liquids or 3,000 t of gases (20.4.1.1.1). Where an installation fits two classes, the higher one applies (20.4.1.2).

2Definitions and flash point

The line between flammable and combustible

TermDefinitionItem
Flammable liquidflash point ≤ 60 °C20.3.1
Treated as flammableliquid with flash point > 60 °C stored or transferred heated to a temperature at or above its flash point20.3.1.1
Flammable gasignites in air at 20 °C and 101.3 kPa20.3.2
Combustible liquidflash point > 60 °C and ≤ 93 °C20.3.3

In practice: petrol and ethanol are flammable; diesel is a combustible liquid. The classification of the installation (Table 1) considers storage capacity, whether permanent or temporary.

3Tanks, containment and ignition sources

What to check in the fuelling area

Leak containment (20.14.4)

Tanks storing flammable and combustible liquids must have leak or spill containment systems, sized and built in accordance with national technical standards. Storing materials, containers and the like inside the containment basin is prohibited, except during maintenance and inspection (20.14.4.1).

Diesel or biodiesel tank inside a building (Annex III)

Inside buildings, a flammable liquid tank is only allowed if buried and intended for diesel or biodiesel. An above-ground tank is the exception: only to feed an emergency power generator, where burying it is shown to be impossible, with a design and a preliminary hazard/risk analysis by a qualified professional.

  • ground floor, basement or open ground floor, in an exclusive area;
  • leak containment system;
  • room enclosed by walls fire-resistant for at least 2 h and a fire door;
  • up to 5,000 L per tank and room, and 10,000 L per building;
  • metal tanks, with fire detection and fighting and properly sized emergency exits;
  • operators trained on the Intermediate Course (Annex III, 2.3).

Control of ignition sources (20.13)

  • electrical installations and equipment in classified areas in accordance with NR-10;
  • measures against the generation, build-up and discharge of static electricity;
  • work permit for flames, heat or sparks in a flammable atmosphere;
  • signs prohibiting ignition sources;
  • suitable, well-maintained vehicles in areas with a flammable atmosphere.

4Worker training

Item 20.12 — what the standard sets by class

All training is the employer's responsibility and expense, during working hours (20.12.1). The type required depends on the activity, on the class of the installation and on whether the worker enters the area and has direct contact with the process (20.12.2).

The six types of course (20.12.3)

  • Introductory Course on Flammables and Fuels — 3 h;
  • Basic Course;
  • Intermediate Course;
  • Advanced Course I;
  • Advanced Course II;
  • Specific Course.

Hours by class (Annex I, Table 1)

ActivityClass IClass IIClass III
Specific, occasional and short durationBasic 4 hBasic 6 hBasic 8 h
Maintenance and inspectionIntermediate 12 hIntermediate 14 hIntermediate 16 h
Operation and emergency responseIntermediate 12 hAdvanced I 20 hAdvanced II 32 h
Occupational health and safetySpecific 14 hSpecific 16 h

Refresher training (Annex I, Table 2)

CourseClass IClass IIClass IIIHours
BasicEvery 3 yearsEvery 3 yearsEvery 3 years4 h
IntermediateEvery 3 yearsEvery 2 yearsEvery 2 years4 h
Advanced IEvery 2 yearsEvery 2 years4 h
Advanced IIEvery year4 h

There are also triggers for refresher training (20.12.9.1): when the accident history requires it; within 30 days of a significant modification; within 45 days of a 2nd or 3rd degree burn with hospitalisation; and within 90 days of a worker's death. Moving up a level requires 8 h of additional training (20.12.6 to 20.12.8).

5Installation records

Installation file, risk analysis and emergency plan

Installation file (20.6)

  • Installation design;
  • Inspection and Maintenance Plan;
  • Risk Analysis (20.7.1);
  • Plan for preventing and controlling leaks, spills, fires and explosions;
  • Emergency Response Plan.

The file must be available to the competent authorities and for consultation by workers and their representatives (20.6.3).

Risk analysis (20.7)

In Class I, a preliminary hazard/risk analysis is prepared. In Classes II and III, a defined methodology coordinated by a qualified professional, with a multidisciplinary team including a worker experienced in the installation. The analyses are reviewed within the periods they themselves recommend and at every significant modification (20.7.5).

Emergency response plan (20.15)

Drills at least once a year, during working hours, involving the workers (20.15.5). The response team undergoes specific medical examinations under NR-7 (20.15.6), and taking part is voluntary, except where the job requires it (20.15.7).

6Incidents and responsibilities

What to report and whose duty it is

Reporting incidents (20.16)

The employer reports to the labour inspectorate and to the workers' union any leak, fire or explosion resulting in death, in a 2nd or 3rd degree burn with hospitalisation, or in activation of the emergency plan with large-scale intervention. The report is made by the 2nd working day after the event (20.16.1.1), and the employer prepares an investigation report with causes and preventive measures (20.16.2).

Client company and contractors (20.17)

The client company and its contractors are responsible for complying with the standard. Safety requirements for contractors' employees must be at least equivalent to those of the client company, which informs them of the risks and assesses the safety performance of the contracted services.

7Ready answers

What to say, with the item at hand

When they askThe answer
“I have a diesel tank on the farm. Does NR-20 apply?”Yes. Fuel storage is governed by NR-20 — NR-31 refers to it. A farm usually falls under Annex II (small installation): it does not become Class I, but it requires records attached to the risk management programme, a containment basin at the tank and the Basic Course for at least three people.
“Do I need a containment basin?”Yes. Item 20.14.4 requires a leak containment system on tanks of flammable and combustible liquids, and storing any material inside the basin is prohibited (20.14.4.1).
“Which flash point defines a flammable liquid?”Up to 60 °C it is a flammable liquid (20.3.1); above 60 °C and up to 93 °C it is a combustible liquid (20.3.3). Diesel is combustible; petrol and ethanol are flammable.
“Can I put the tank inside the shed?”Inside a building, only buried (Annex III, 1). An above-ground tank only to feed an emergency generator, with a design and preliminary hazard analysis by a qualified professional, 2 h fire-resistant walls and a limit of 5,000 L per tank and 10,000 L per building.
“How many people do I have to train?”At a small Annex II installation, at least three on the Basic Course (Annex II, 1.1). At a retail or wholesale installation, the ratio in Table 3 (from 2 to 4 or more, according to capacity).
“How often do I have to refresh the training?”A 4 h refresher, with frequency by course and class (Table 2): Basic every three years; Intermediate every three or two years; Advanced II every year. There are also triggers after an accident (within 30, 45 or 90 days).
“There was a serious accident. Do I have to report it?”Yes. In case of death, a 2nd or 3rd degree burn with hospitalisation or a large-scale emergency, report to the labour inspectorate and to the union by the 2nd working day (20.16.1), with an investigation report (20.16.2).
“Is this a buyer requirement?”No. NR-20 is a regulation with the force of law, enforced by the Labour Inspector, with its current text consolidated by MTE Ordinance 60 of 21 January 2025.

Does your property or cooperative store fuel within the rules?

Brasil Sustentabilidade supports farmers, cooperatives and traders in classifying installations under NR-20, in the installation records and in training teams.

Talk to the team