Food and beverage safety is a critical matter for plant managers, and when it comes to storing food using ammonia refrigeration systems, ensuring the safety of workers is of utmost importance. Ammonia is one of the most widely produced chemicals in the world and has become the preferred choice for industrial refrigeration due to its superior cooling abilities and low impact on the environment. However, in large doses, ammonia is a highly toxic chemical that can be lethal to humans.
Many industrial food and beverage facilities use ammonia as a refrigerant but not all have the proper equipment and protocols in place to ensure workers are kept safe when refrigeration leaks occur. Food and beverage workers have the right to workplace safety, and as ammonia is toxic to humans, even in low PPM levels, personal protection equipment (PPE) is needed when working with ammonia.
This article discusses the risks of ammonia exposure, the different types of PPEs available, and the legislative requirements associated with them.
Industrial Ammonia Refrigeration System Risks
Industrial refrigeration safety is very important. Anhydrous ammonia is one of the most effective refrigerants, however, it is also one of the most dangerous.
Despite preventative measures and routine maintenance efforts, refrigerant leaks can and do occur. At any given time, thread sealants, Schrader caps, neoprene o-rings, or other parts of the refrigeration equipment could wear and spring a leak, posing a huge risk to a food and safety operator.
Ammonia is a colorless gas with a very distinct and familiar odor that becomes explosive when large quantities are released into the atmosphere and ignited. This potentially lethal gas is compressed under extreme pressure and when used in refrigerated systems is transformed into a liquid state referred to as anhydrous ammonia. The clear fluid evaporates quickly at room temperature and a major spill poses a danger, not only because it is flammable, but also because it is toxic to those who breathe it in.
But what effect does ammonia have on those exposed to it? The risks to food and beverage workers increase as the levels of ammonia exposure go up.
Gas is measured in parts per million (PPM). The sharp, penetrating, odor of ammonia can be detectable at very low concentrations, even as small as 5 PPM and its effects on humans can be extremely hazardous.
Here is a quick overview of the impacts ammonia can have on humans who breathe in anhydrous ammonia:
- Low levels (5 ppm): sharp odor is detectable.
- Moderate levels: irritation to the eyes and respiratory tract; may cause nausea as well as vomiting.
- High concentration levels (above 50ppm): possible ulcerations to the eyes and severe irritation to the respiratory tract.
- Extremely high concentrations (300 to 500 ppm): potentially fatal; can cause fluid build-up in the lungs and severe shortness of breath.
Emergency Response Preparedness
Since ammonia leaks can and do occur even when preventative measures are taken, it’s vital that food and beverage workers be provided with the necessary protective equipment when dealing with refrigerants. Ammonia refrigerants indicate the need for face protection when handling the chemical. Many facilities fail to have the right personal protection equipment on hand while those that do often fail to have the worker use it as required.
Respirator Devices for Emergency Preparedness
A respirator is a device designed to protect the wearer from inhaling harmful dust, fumes, vapors, or gases. Respirators come in a wide range of types and sizes and can range from single-use models to re-usable with replaceable cartridges. With each category, different technologies are employed to reduce or eliminate noxious airborne contents.
There are two main categories of respirators:
- Air-purifier respirators: contaminated air is forced through a filter element.
- Air-supplied respirators: an alternative supply of air is delivered.
SCBAs for Emergency Preparedness
A self-contained breathing apparatus (SCBA) provides breathable air in cases where workers are exposed to immediate danger to life and health atmosphere.
There are two types of SCBAs:
- Open Circuit SCBA: This industrial breathing set is filled with filtered compressed air and typically contains two stages of regulators. The first stage reduces air pressure to allow it to be carried to the mask and the second stage regulator reduces it even further to a level just above atmospheric pressure. This air is then fed to the mask via either a demand valve that activates on inhalation or a continuous positive pressure valve.
- Closed Circuit SCBA: This type filters, supplements, and re-circulates exhaled gas. This type is used when a longer-duration supply of breathing gas is needed.
These SCBAs are to be used when the ammonia atmosphere less than 300 ppm and should also be suitable for the temperature in which the SCBA will be worn. It is important for food and safety plant managers to periodically verify that employees are trained and fit tested for the proper use of this emergency equipment.
Ammonia Refrigeration System Safety Legislation
Although legislation requires that vapour gas detectors be installed and in proper working order, there is no direct legislative requirement for personal protective equipment to be worn where ammonia refrigeration systems are in operation.
In the past, Technical Standards and Safety Authority has confirmed there is no specific obligation under the Operating Engineers Regulation or Boiler and Pressure Vessels Act. Additionally, there is no direct requirement for SCBA within the CSA Mechanical Refrigeration Code and it isn’t an enforcement of the Ministry of Labor (MOL).
Workers have the right to a safe working environment, and so food and beverage operational managers are required to perform certain responsibilities related to emergency response preparedness:
- Ensure equipment, materials and protective devices are provided.
- Ensure equipment is maintained in good condition.
- Enforce the use of personal protective equipment.
- Provide information on the use of personal protective equipment to staff.
- Acquaint workers with proper handling, storage, disposal, and transport of equipment.
- Monitor levels of chemicals in the workplace and post in an accessible location.
- Limit worker exposure to chemicals.
- Carry out training programs.
Food and beverage plant owners and managers must make their own interpretation of these duties laid out by their state or province. It is their duty to adequately prepare staff for emergencies related to industrial refrigerated systems. Selecting the proper PPE and ensuring workers are fitted, and know how to care for and use the equipment properly will go a long way toward ensuring occupational health and safety in the workplace.
Ammonia Refrigeration System Resources
Plant managers who want to read more detailed information about how to prevent and control exposure in ammonia refrigeration systems may find the following resources helpful:
Ammonia Refrigeration Systems is an extensive manual published by WorkSafe BC. Not only does the article describe the hazards of ammonia with great detail, it also outlines how to prevent and control exposure.
The Ammonia Refrigeration E-Tool, created by the Occupational Safety & Health Administration, focuses on identifying and controlling the hazards associated with operating and maintaining ammonia refrigeration systems.Ammonia Recovery Unit (ARU) is a Berg Chilling Systems product that assists workers in the safe removal of ammonia from refrigeration systems. This thoughtfully designed and purpose built machine can operate in any industrial environment and has been Berg built to last.