Ammonia Gas Leak Detection

Ammonia Gas Leak Detection Solutions

Discover reliable ways to detect ammonia leaks and take safety to the next level.

Ammonia Usage

Ammonia (NH3) is widely used in a number of industries. Industrial grade ammonia is typically supplied either as Anhydrous Ammonia in tanks (in pressurized or refrigerated state) or in liquid form (mixed with water). As ammonia production is expected to grow, there should be an understanding of several risks associated with the use of this gas. Ammonia is a toxic gas and the proper safety monitoring procedures and equipment must always be in place to avoid serious accidental injury or death. Moreover, it is combustible at higher concentrations, which poses additional risks for large industrial users.

Discover the risks, challenges and solutions for your ammonia applications.

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Ammonia is produced by reacting hydrogen with nitrogen over a catalyst. Main source of hydrogen is natural gas reforming. Electrolysis of water using green energy is an emerging alternative.


The majority of ammonia produced annually is consumed in the manufacture of fertilizers. In solid or liquid states, ammonia salts and solutions are the active components of most synthetic fertilizer.


Ammonia is used in various production processes, including rubber and leather, pulp and paper, pharmaceutical, and many others. Industrial grade ammonia is typically supplied either as anhydrous ammonia in tanks or in liquid form.


Ammonia is used as a refrigerant in cooling installations located in freezers, coolers, loading docks, production areas, machine rooms and air handling units. Ammonia is an alternative to halogenated refrigerants, as it is also safer for the environment, especially the ozone layer.

Ammonia Detection Specifics

Large industrial plants present a congested array of complex equipment, such as tanks, pumps, pipelines, and valves. The size and dispersion of a gas leak is affected by the size of the leak, the gas pressure in the system, its density, ambient temperature, nearby air flow including wind, and other factors.

Ammonia is lighter than air, accumulating in upper areas of the site. It can also form clouds travelling with the wind beyond the plant if an accidental release occurs outdoors. However, if there is a water vapor in the gas mixture, then the cloud often remains lower to the ground and can then be a serious issue inside a plant for employees.

Ammonia Hazards: Toxic and Combustible

Reliable ammonia detection helps provide both personnel and facility safety but also product quality where it is used for production. The major concern with ammonia gas leaks relates to the effects on worker’s health and typical exposure symptoms will depend on concentration and time of exposure. The human nose may detect concentrations as low as 5 ppm; however, leaking ammonia can reach much higher concentrations:


5 ppm
3.5 mg/m3

Signs & Symptoms

Detectable pungent odor without adverse health effects

20-25 ppm
14-18 mg/m3

Signs & Symptoms

The concentration at which a worker can be exposed to for a normal 40 hour work week without adverse effects*

35-50 ppm
25-36 mg/m3

Signs & Symptoms

Workers should be able to withstand a 15-minute exposure without adverse effects*

50 ppm
35 mg/m3

Signs & Symptoms

Irritation to eyes, nose and throat (2 hours’ exposure). Later headaches, loss of the sense of smell, nausea, and vomiting

100 ppm
70 mg/m3

Signs & Symptoms

Rapid eye and respiratory tract irritation causing coughing and wheezing

250 ppm
174 mg/m3

Signs & Symptoms

Tolerable by most people (30–60 minutes’ exposure)

300 ppm

Signs & Symptoms

NIOSH - Immediately Dangerous to Life and Health.

700 ppm
488 mg/m3

Signs & Symptoms

Immediately irritating to eyes and throat

>1,500 ppm
>1,045 mg/m3

Signs & Symptoms

Pulmonary oedema, coughing, laryngospasm

2,500–4,500 ppm
1,740–3,134 mg/m3

Signs & Symptoms

Fatal (30 minutes’ exposure)

5,000–10,000 ppm
3,480–6,965 mg/m3

Signs & Symptoms

Rapidly fatal due to laryngeal swelling or pulmonary oedema, may also cause skin damage


PHE Centre for Radiation, Chemical and Environmental Hazards, Ammonia Toxicological Overview

U.S. Environmental Protection Agency Region 7, Accident Prevention And Response Manual For Anhydrous Ammonia Refrigeration System Operators

* See below indicative ammonia limit values for occupational and plant safety

Indicative Ammonia limit values for occupational and facility safety

There are recommended indicative occupational exposure limit values for Ammonia exposure which vary depending on the country.


CAS No: 7664-41-7
Long term – 8-hour (TWA) Short term – 15-minute (STEL)
ppm mg/m3 ppm mg/m3
European Union 20 14 50 36
France 10 7 20 14
Germany 20 14 40 28
Italy 20 14 50 36
Spain 20 14 50 36
United Kingdom 25 18 35 25
Turkey 20 14 50 36

The Americas

CAS No: 7664-41-7
Long term – 8-hour (TWA) Short term – 15-minute (STEL)
ppm mg/m3 ppm mg/m3
USA - ACGIH (TLV) 25 17 35 24
USA - NIOSH (REL) 25 18 35 27
USA - OSHA (PEL) 50 35
Canada 25 17 35 24
Brazil 25 17 35 24


CAS No: 7664-41-7
Long term – 8-hour (TWA) Short term – 15-minute (STEL)
ppm mg/m3 ppm mg/m3
Australia 25 17 35 24
New Zealand 25 17 35 24


CAS No: 7664-41-7
Long term – 8-hour (TWA) Short term – 15-minute (STEL)
ppm mg/m3 ppm mg/m3
Japan (JSOH) 25 17
People's Republic of China 20 30
Singapore 25 17 35 24
South Korea 25 18 35 27
India 25 18 35 27

Middle East

CAS No: 7664-41-7
Long term – 8-hour (TWA) Short term – 15-minute (STEL)
ppm mg/m3 ppm mg/m3
UAE 25 35
Saudi Arabia 25 35
Qatar 25 18 35 25
Oman 25 17 35 24
Bahrain 25 18 35 27


CAS No: 7664-41-7
Long term – 8-hour (TWA) Short term – 15-minute (STEL)
ppm mg/m3 ppm mg/m3
South Africa 50 70
Egypt 25 18 35 27

Make sure you are aware what limit values applies for your location and check our Response Guide for more data.

Sensor Technologies for Ammonia Detection

Ammonia detection systems that deploy diverse, complimentary early hazard detection technologies can counteract the possible effects of leaks, preventing equipment or property damage, personal injury, and loss of life.

Fertilizer Production

Majority of ammonia is used in agriculture industry as fertilizers. Liquid fertilizer consists of ammonia, ammonium nitrate, urea, and aqua ammonia; also used to produce ammonium and nitrate salts. Typical fertilizer plant process and distribution site areas that require ammonia detection include:

  • Spray towers
  • Plant perimeter monitoring
  • Pumps and compressors
  • Pipelines and valves
  • Storage tanks
  • Rail or truck loading/unloading
  • Port shipping terminals

These areas are crowded with equipment which makes perimeter monitoring essential to help protect the entire plant and surrounding community. To help fertilizer plants better address ammonia gas detection concerns open path technology can be used for multiple process locations. Moreover a multi-sensor layered approach also with various types of point fixed gas detector and sampling systems provides redundancy to help guard people and equipment.

Industrial Processing

There are number of industries using ammonia for production processes. In rubber and leather Industries, ammonia is used for the stabilization of natural and synthetic latex to prevent premature coagulation.

Pulp and paper Industry uses ammonia for pulping wood and as a casein dispersant in the coating of paper.

Ammonia is also widely used in manufacturing of drugs, inhibiting the growth and multiplication of certain types of bacteria, in addition to various other uses in pharmaceutical manufacturing and as a neutralizing agent.

These applications involve manual and automated processes where personnel have to supervise and control the production. Reliable and very low level of ammonia detection is important for preserving the health and life of personnel.

Refrigeration / Cooling Systems

Ammonia is a widely used refrigerant in beverage and food processing. Typical areas where cooling installations are located include:

  • Freezers
  • Coolers
  • Loading docks
  • Production areas
  • Machine rooms
  • Air Handlers

Fast changing temperatures and humidity levels in refrigeration systems can affect the ammonia level and also the lifetime of typical sensors. Other gases and odors in the plant may cause traditional electrochemical sensors to respond and can lead to unnecessary and costly false alarms. Therefore choice of appropriate and reliable technology immune to changing conditions is important and unique photoacoustic infrared sensor meets these requirements.

Ammonia Production & Storage

Most of the global production of ammonia is based on steam reforming of natural gas. During synthesis natural gas molecules are reduced to carbon and hydrogen. The hydrogen is reacted with nitrogen at a high pressure and temperature to produce ammonia. Additional source for obtaining hydrogen necessary for ammonia production comes from water electrolysis. The process splits water into hydrogen and oxygen by using electricity.

The processes involved in ammonia production require gasses to be under high pressure which possess the risk of gas leakage and hydrogen is one of them. Ultrasonic technology greatly supports, traditional catalytic bead gas detectors for detection of hydrogen resulting in faster leak detection. Additionally installed hydrogen flame detectors allow for identification of invisible fires and prevent consequential explosions.

Another risk is related to outdoor exposure to ammonia, from leaks and spills at production plants and storage facilities. Open path toxic gas detectors help to mitigate that risk covering large areas where quick dilution of leaking gas can be a significant issue.


Sensing Technology Animations

See at a glance how ammonia sensing technologies work for your safety.

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