Ambient air and emission monitoring in Uzbekistan: requirements of the new national standards
Oʻz MSt 194:2024 and Oʻz MSt 195:2024 are new national standards for environmental monitoring, made mandatory by Cabinet of Ministers Resolution No. 783 of November 2024. They apply to category I and II environmental-impact enterprises, state monitoring organisations and equipment manufacturers.
1. What the standards are for
The two standards, in force since 28 August 2024, regulate the following:
- Oʻz MSt 194:2024 — general technical conditions for automatic monitoring stations (AQMS) that measure ambient air quality
- Oʻz MSt 195:2024 — general technical conditions for continuous emission monitoring systems (CEMS) that measure emissions from stationary industrial sources
Both standards were developed with reference to the international BS EN 14181 and require results to be transmitted in real time to the Unified Geoinformation Database of the environmental monitoring system.
2. AQMS: ambient air monitoring stations (Oʻz MSt 194:2024)
Measured parameters
| Category | Parameters |
|---|---|
| Gaseous species | NO₂, SO₂, NH₃, CO, O₃, H₂S |
| Particulate matter | PM2.5, PM10, total dust |
| Meteorological unit | temperature, humidity, pressure, wind speed and direction |
AQMS: key technical requirements
- Ingress protection: IP55 or better
- Operating temperature range: −40 °C to +60 °C
- Mean time between failures (MTBF): at least 15,000 hours (P=0.95)
- Measurement frequency: at least once every 180 seconds
- Backup power: at least 4 hours
- Data archive: at least 12 months
- Data transmission: 4G and GPRS as a minimum, Wi-Fi for local configuration
- Station weight: 5–50 kg
- Service life: at least 5 years; sensors at least 2 years
3. CEMS: emission monitoring stations (Oʻz MSt 195:2024)
Thresholds above which a station is mandatory, g/s
| Pollutant | Threshold |
|---|---|
| Particulate matter | 0.833 |
| Sulphur dioxide (SO₂) | 8.333 |
| Nitrogen oxides (NOx) | 8.333 |
| Carbon monoxide (combustion-completeness indicator) | 1.388 |
| Carbon monoxide (all other cases) | 27.777 |
| Hydrogen fluoride (HF) | 0.083 |
| Hydrogen chloride (HCl) | 0.417 |
| Hydrogen sulphide (H₂S) | 0.083 |
| Ammonia (NH₃) | 0.417 |
A station is also mandatory when any single substance accounts for more than 60% of the total emission of all stationary sources.
CEMS: key technical requirements
- Ingress protection: IP54 or better
- Response time (T90): no more than 45 seconds
- Mean time between failures (MTBF): at least 24,000 hours
- Measurement frequency: at least once per minute
- Zero / span drift: ±2% per week (full scale)
- Backup power: at least 4 hours
- Permitted annual downtime (for maintenance): no more than 28 calendar days
- Service life: at least 10 years; sensors at least 2 years
Substances subject to mandatory monitoring, by industry
| Industry | Monitored substances |
|---|---|
| Aluminium production | PM, fluorides, CO and CO₂ |
| Cement | PM, NOx, SO₂, CO and CO₂ |
| Chlorine production | Cl₂, HCl, CO and CO₂ |
| Fertilisers | PM, HF, CO and CO₂ |
| Ferrous metallurgy (steel, cast iron) | PM, NOx, SO₂, CO and CO₂ |
| Alkalis (electrolysis) | Cl₂, HCl, CO and CO₂ |
| Petrochemicals (oils, diesel, synthetic fuel) | PM, NOx, SO₂, SO, CO and CO₂ |
| Power plants (other than thermal) | PM, NOx, SO₂, CO and CO₂ |
| Thermal power plants | PM, NOx, SO₂, total mercury, CO and CO₂ |
| Non-ferrous metallurgy (zinc, copper, titanium) | PM, SO₂, CO and CO₂ |
| Boiler units and boiler houses | PM, NOx, SO₂, CO and CO₂ |
4. AQMS and CEMS: a short comparison
- AQMS under Oʻz MSt 194
- Monitoring ambient air quality
- CEMS under Oʻz MSt 195
- Monitoring emissions from industrial sources
5. How to achieve compliance
If you need advice or technical support in selecting stations that meet the requirements of these standards, certifying them and integrating them into the Unified Information Database, get in touch with us.
Source: Oʻz MSt 194:2024, Oʻz MSt 195:2024 (Uzbek Institute of Standards, order No. 22/MSt of 28 June 2024). Full text at standart.uz, nrm.uz or lex.uz.
The stations the standards require, in 3D
On this topic
CEMS and AQMS stations, sampling, gas analysers, dust monitors and online water and effluent monitoring — with data transmission to the regulator.
Open →CEMS/AQMS architectureFrom probe to emissions report: sampling, line, conditioning, analysers, DAHS, calibration, quality assurance and archive.
Open →CalculatorsFour working tools for preliminary estimates: baghouse filtration area, cartridge quantity, CEMS threshold screening and reverse-osmosis balance.
Open →Does your site meet these requirements?
We will compare your emissions against the thresholds in the standard and tell you whether a station is mandatory. Engineer visit and measurements are free of charge.