National Technical Regulation QCVN 26:2025/BNNMT for Noise

QCVN 26:2025/BNNMT

NATIONAL TECHNICAL REGULATION ON NOISE

QCVN 26:2025/BNNMT

Foreword

QCVN 26:2025/BNNMT is compiled by the Department of Environment, proposed by the Department of Science and Technology, appraised by the Ministry of Science and Technology of Vietnam, and promulgated by the Minister of Agriculture and Environment of Vietnam under Circular No. 01/2025/TT-BNNMT dated May 15, 2025.

QCVN 26:2025/BNNMT replaces QCVN 26:2010/BTNMT.

NATIONAL TECHNICAL REGULATION ON NOISE

1. GENERAL PROVISIONS

1.1. Scope

This Regulation provides for the maximum noise limit in areas where humans live, operate, and work to reduce negative impacts, protect health, and improve life quality for humans.

This Regulation provides for noise emitted from production, business, and service facilities, construction works in progress, traffic vehicles, and civic activities.

This Regulation shall not be applied to assess noise encountered in the labor environment or workplace or in the premises of production, construction, trade, and service facilities affected by their own noise.

1.2. Regulated entities

This Regulation applies to environmental authorities, organizations, and individuals relevant to noise emission in the territory of the Socialist Republic of Vietnam.

1.3. Interpretation of terms

1.3.1. Noise in this regulation shall be construed as loud sounds emitted from the use of devices, machinery, instruments, tools, and other sources that affect specific areas and cause discomfort to humans.

1.3.2. Affected areas refer to areas where noise measurement, monitoring, and control are carried out.

1.3.3. Production, business, and service facilities and civic activities that can emit noise according to this regulation include:

1.3.3.1. Production, business, and service facilities and civic activities that use devices, machinery, instruments, and tools that emit noise by capacity, type, and quantity are prescribed in the Appendix enclosed with this Regulation.

1.3.3.2. Production, business, and service facilities and civic activities that do not use devices, machinery, instruments, and tools that emit noise by capacity, type, and quantity are prescribed in the Appendix enclosed with this Regulation.

1.3.4. Background noise level refers to the noise level measured at the measurement location of the affected area when no noise is emitted from the noise source to be measured.

1.3.5. Noise classification

a) Continuous noise refers to noise emitted continuously from a noise source without interruption.  Continuous noise includes:

- Stationary noise refers to continuous noise with a sound pressure level that does not vary significantly during the time the noise is emitted;

- Fluctuating noise refers to continuous noise with a sound pressure level that varies significantly but not in the form of impulses.

b) Impulsive noise refers to noise emitted during a very short duration (under 1 second) from a determined noise source that may recur during the measurement duration;

c) Intermittent noise refers to noise emitted continuously from a determined noise source that is interrupted for a specific duration, with each noise emission lasting at least 1 second.

1.3.6. Measurement duration refers to the duration used as the noise emission duration during which the measurement is carried out continuously.

1.3.7. Frequency-weighted sound pressure level (LA) is ten times the base-10 logarithm of the ratio between the time-based squared sound pressure level and the squared reference value in decibels (dBA):

p_a and p₀ are sound pressure levels in pascals (Pa)

p₀ = 20 µPa

1.3.8. Equivalent continuous sound pressure level (L_eq,T) is ten times the base-10 logarithm of the ratio between the time-averaged sound pressure p_a during measurement duration T and the squared reference sound pressure p₀.

Where:

p_A(t) is the instantaneous A-weighted sound pressure at time t;

p₀ = 20 µPa.

T: noise measurement duration (starts at t1 and ends at t2)

L_Aeq,T: A-weighted equivalent sound pressure.

1.3.9. 90th percentile sound pressure level (L₉₀) refers to the sound pressure level that is exceeded for 90% of the measurement duration.

1.3.10. Sound exposure level (L_E) is ten times the base-10 logarithm of the ratio between the sound exposure (E) and the reference value E₀.

Where:

E₀ = 400µPa²s

2. TECHNICAL PROVISIONS

2.1. Affected area classification

The classification of affected areas in this Regulation shall be carried out as follows:

2.1.1. Area A includes the following facilities and works:

- Educational institutions according to the Law on Education and vocational education institutions according to the Law on Vocational Education;

- Medical examination and treatment facilities according to the Law on Medical Examination and Treatment; senior care facilities according to the Law on the Elderly;

- Museums and libraries;

- Religious works;

- Offices of agencies of the CPV, National Assembly of Vietnam, Government of Vietnam, and President of Vietnam and offices of Ministries, central authorities, People’s Committees, and affiliates at various levels; headquarters of political organizations, socio-political organizations, and socio-vocational political organizations and headquarters and offices of organizations and individuals.

2.1.2. Area B includes the following facilities and works:

- Houses: apartment buildings and other types of collective houses; separate houses;

- Hotels, guesthouses, motels, and other accommodation service establishments;

2.1.3. Area C includes the following facilities and works:

Livestock, cultivation, and aquaculture facilities.

2.1.4. Area D includes the following facilities and works:

- Outdoor and indoor works of sports;

- Parks;

- Conference centers, theaters, cultural houses, clubs, cinemas, circuses, dance halls, amusement/entertaining works, and other cultural works;

- Malls, supermarkets, markets, stores, restaurants, and other similar works.

2.1.5. Area E includes the following facilities and works:

- Airport, waterway, and railway terminals, bus stations, and parking lots;

- Concentrated production, business, and service areas and industrial works according to the law;

- National defense and security works that are not used for purposes similar to those of works in areas A, B, C, and D;

- Other works.

2.2. Permissible maximum value of noise emitted from production, business, and service facilities and civic activities according to Section 1.3.3.1 measured in affected areas

The permissible maximum value of noise emitted from production, business, and service facilities and civic activities according to Section 1.3.3.1 measured in affected areas is prescribed in the following Table:

Table 1. Permissible maximum value of noise emitted from production, business, and service facilities and civic activities according to Section 1.3.3.1

[Unit: dBA]

Where:

It is permitted to adjust the permissible maximum value threshold of noise prescribed in Table 1 according to specific noise emission duration as follows:

Table 2. Adjustment values of thresholds according to noise emission duration from production, business, and service facilities and civic activities according to Section 1.3.3.1

2.3. Permissible maximum value of noise emitted from other sources

The permissible maximum value of noise emitted from other sources is prescribed in Table 3.

Table 3. Permissible maximum value of noise emitted from other sources

[Unit: dBA]

Where noise is emitted from construction sites in progress during the day, it is permitted to adjust the permissible maximum value threshold prescribed in Table 4 as follows:

Table 4. Adjustment values of thresholds according to noise emission duration during the day from construction sites in progress

Note:

i) ^(*) Noise emitted from speakers does not apply to speakers or horns of specialized vehicles of agencies or units permitted for use under the law and speakers of licensed art performance programs.

ii) ^(**) In addition to the application of the threshold adjustments according to Table 4, it is permitted to adjust +3dBA during the day regarding the maximum value threshold for construction sites involving the use of pile drivers, pile extractors, drilling machines, and excavators.

iii) In addition to the application of threshold adjustments prescribed in Table 4, it is mandatory to adjust -5dBA to the permissible maximum value of construction sites in progress during off days according to regulations for areas A and B.

iv) ^(***) “In the same building” refers to a building with a roof, pillars, or walls that are in a monolithic structure of construction works according to the law. The permissible maximum value for noise emitted from other sources for “in the same building” shall only apply to the following production, business, and service facilities:

- Gym and fitness facilities, martial arts dojos, and dance clubs;

- Music teaching facilities;

- Bars, restaurants, supermarkets, and karaoke facilities.

2.4. Permissible maximum value for noise emitted from traffic vehicles

The permissible maximum value for noise emitted from traffic vehicles is prescribed in Table 5.

Table 5. Permissible maximum value for noise emitted from traffic vehicles

[Unit: dBA]

2.5. Adjustment value based on background noise level

Continuous background noise level measurement shall be carried out when no noise is emitted from the noise source, which will be measured in an affected area for at least 5 minutes, using the Leq results as the background noise level. Where it is impossible to separate the noise emitted from the noise source to measure the noise level, conduct the measurement in the affected area for at least 5 minutes, using the L90 value as the background noise level.

- Where the background noise level is lower than the noise level measured in the affected area from 10 dBA or more, the noise level measurement results shall be used for comparison and assessment according to the prescribed thresholds of this Regulation.

- Where the background noise level is lower than the emitted noise level and the difference between the background noise level and the emitted noise level is lower than 10 dBA, apply adjustment values to the noise level measurement results as follows:

Table 6. Adjustment value of measurement results based on background noise level

3. DETERMINATION METHODS

3.1. Noise level measurement locations

- The measurement location is inside the boundary of an affected area;

- The measurement location shall have the nature of general representativeness, provide accurate measurement results, and properly reflect the emitted noise; it is permitted to conduct the measurement at a location that may be most affected;

- The measurement location shall avoid other noise sources that are not relevant to the noise source to be measured. When it is impossible to avoid the effects of other noise sources, select a reasonable measurement time to maximize the elimination of impacts from other noise sources;

- Regarding outdoor measurement locations, select a location that is at least 3,5 m away from possible echoes and at least 1,2 m or 1,5 m above the ground.

- Regarding indoor measurement locations, select a location that is at least 1 m away from possible echoes and at least 1,2 m or 1,5 m above the ground.

3.2. Noise level meters

- The monitoring and measurement of noise levels to assess conformity with this Regulation shall use type-1 sound level meters according to TCVN 12527-1:2018 – Electroacoustics – Sound level meters – Part 1: Specifications

- Meters shall be inspected and calibrated according to the law.

3.3. Noise level measurement conditions

Noise levels are affected by meteorological conditions, especially when the transmission distance is large. Therefore, it is mandatory to maximize the elimination of the effects of meteorological conditions during the measurement.

- The measurement shall be carried out when there is no rain;

- The meter must have a windshield. The measurement shall not be carried out when there are level-4 winds or higher (wind speed from 5,5 m/s or higher) at the noise level measurement location.

The weather conditions at the measurement location shall be described and recorded in noise level measurement minutes throughout the measurement.

3.4. Noise level measurement duration

- Noise levels shall be measured continuously during the measurement for at least 15 minutes.  When conducting a continuous measurement, use the measurement duration as the noise emission duration.

- Regarding impulsive noise, the noise level measurement shall be carried out for at least 15 minutes.  Where a 15-minute measurement does not obtain 50 measurement values, continue the measurement until there are 50 values.

3.5. Noise level measurement methods

Noise level measurement methods shall comply with the following national standards:

- TCVN 7878 - 1:2018 (ISO 1996 - 1:2016) Part 1: Basic quantities and assessment procedures.

- TCVN 7878 - 2:2018 (ISO 1996 - 2:2017) Part 2: Determination of sound pressure levels.

3.6. Measurement results and conformity assessment

3.6.1. Regarding continuous noise

The measurement results shall be used as the equivalent sound pressure level L_eq,T during the measurement duration to calculate and assess conformity with this regulation.

3.6.2. Regarding intermittent noise and impulsive noise

Determine the equivalent sound pressure level for each occurrence of intermittent noise or impulses (for impulsive noise), and then determine the equivalent sound level during the whole measurement duration as follows:

- Determine the sound exposure level LE for each occurrence of intermittent noise or each impulse following the formula prescribed in Section 1.3.10.

- Determine the equivalent sound level during the whole measurement duration as follows:

Where:

- L_E1, L_E2… L_En: sound exposure level by each occurrence of intermittent noise of each impulse during the measurement duration (dBA);

- T: measurement duration (s);

- T₀: reference duration.  T₀ = 1s.

L_eq,T shall be used for calculation and assessment of conformity with this regulation.

4. MANAGEMENT PROVISIONS

4.1. The monitoring of noise levels and use of monitoring results for state management objectives concerning the environment shall be carried out by organizations meeting the requirements and conditions for environmental monitoring capacity according to the law.

4.2. When conducting the measurement and assessment of the background noise level, where the background noise level measured in the affected area has Leq higher than the respective level prescribed in this Regulation, refrain from conducting the assessment of noise emitted from the noise source to be measured and adopt measures to reduce noise emitted to the affected area.  Noise emission shall be assessed as complying and conforming with this Regulation when the noise level measurement and monitoring results in the affected area do not exceed the respective permissible value prescribed in Section 2 on technical provisions.

4.3. When the noise level in affected areas exceeds the respective permissible value prescribed in this Regulation, state management authorities, organizations, and individuals shall adopt measures to reduce the impacts of emitted noise on affected areas.

4.4. The results of the assessment of compliance and conformity with this Regulation shall be the ground for state management authorities to conduct assessment and handling according to the law.

5. RESPONSIBILITIES OF ORGANIZATIONS AND INDIVIDUALS

5.1. Organizations and individuals that may cause noise shall ensure that the noise levels emitted to affected areas do not exceed the permissible limit prescribed in this Regulation.

5.2. State management authorities shall conduct noise level measurement and monitoring in affected areas and develop comprehensive plans for noise control, ensuring compliance with the permissible limit prescribed in this Regulation.

6. IMPLEMENTATION

6.1. Environmental authorities shall instruct, inspect, and supervise the implementation of this Regulation.

6.2. Where any document cited in this Regulation is amended or replaced, comply with its new edition./.

APPENDIX

List of types and quantities of devices emitting noise regarding production, business, and service facilities and civic activities

1. Devices, machinery, and tools of facilities by capacity

1.1.) Air compressors with a capacity of 7,5kW or more or screw compressors with a capacity of 37,5kW or more;

1.2) Ventilation fans with a capacity of 7,5kW or more;

1.3) Metal forging and forming machines with a capacity of 7,5kW or more (excluding pneumatic ones);

1.4) Metal cutting machines with a capacity of 7,5kW or more;

1.5) Non-hydraulic presses with a capacity of 7,5kW or more or hydraulic presses with a capacity of  22,5kW or more (excluding hydraulic metal bending machines);

1.6) Sand separators with a capacity of 7,5kW or more;

1.7) Grinders (including coarse and fine grinders) with a capacity of 7,5kW or more;

1.8.) Actuators with a capacity of 22,5kW or more;

1.9) Mechanical equipment combinations with a capacity of 7,5kW or more;

1.10) Centrifuges with a capacity of 15kW or more;

1.11) Concrete mixers and asphalt mixers with a capacity of 15kW or more or other mixers with a capacity of 37,5kW or more;

1.12) Other mechanical processing machines (lathes, milling machines, grinders, and drills) with a capacity of 37,5kW or more;

1.13) Fine powder grinders with a capacity of 22,5kW or more;

1.14) Power saws with a capacity of 15kW or more;

1.15) Wood processing machines (planers, cutters, grinders, CNC machines, and drills) with a capacity of 15kW or more;

1.16) Letterpress printing machines (typo) with a capacity of 15kW or more, offset printing machines with a capacity of 75kW or more, or other printing machines with a capacity of 37,5kW or more;

1.17) Rollers with a capacity of 37,5kW or more;

1.18) Rice mills with a capacity of 22,5kW or more;

1.19) Extrusion and injection molding machines with a capacity of 37,5kW or more;

1.20) Casting machines with a capacity of 22,5kW or more (including die casting machines);

1.21) Concrete pipe and pile manufacturing machines with a capacity of 15kW or more;

1.22) Pumps with a capacity of 15kW or more;

1.23) Metal spinning machine with a capacity of 22,5kW or more (including wet drawing machines, twisting machines, and winding machines);

1.24) Paper-making machines with a capacity of 22,5 or more;

1.25) Coal briquette machines with a capacity of 7,5kW or more;

1.26) Production, business, and service facilities using devices prescribed in Section 1.1 through Section 1.25 with a smaller capacity for each type of machine, and the total capacity of all the devices in the list above exceeds 37,5kW (or exceeds 75kW in cases where offset printers are used). 

2. Devices, machinery, and tools according to quantity at facilities

2.1.) At least 100 industrial sewing machines;

2.2) At least 4 block and cement brick manufacturing machines;

2.3) At least 1 automatic bottle manufacturing machine;

2.4) At least 1 metal box manufacturing machine;

2.5) At least 2 automatic packaging machines;

2.6) At least 40 weaving machines (excluding knitting machines);

2.7) At least 1 spinning machine or 5 winding machines.

3. Devices, machinery, and other tools

3.1) Heavy metal forging and forming machines with a hammer weight greater than 0,5 tons;

3.2) Power generators with a capacity of 120kW or more (excluding hydraulic power generators);

3.3) At least 2 grinders, each with a capacity of 3,75kW or more;

3.4) At least 1 stone cutting machine with a capacity of 7,5kW or more.

Note: The capacity of devices, machinery, and tools emitting noise shall be calculated for 1 device.