Guidelines for Changing Oil in Ammonia Refrigeration Systems

Refrigeration systems are regulated by the Boiler, Pressure Vessel and Compressed Gas Regulations under the Public Safety Act. The standard for the design, construction, installation, inspection and maintenance of refrigeration systems is the CSA B52-05, “Mechanical Refrigeration Code”. The Code contains specific requirements for machinery rooms, ventilation systems and refrigerant vapour detectors. Owners must ensure their facilities meet these requirements.

The Occupational Health and Safety Act and Regulations establish minimum standards to protect the health and safety of workers who work on or around refrigeration systems. Owners must ensure that these standards are followed by employees or contractors who work on their refrigeration systems.

The draining of oil from and addition of oil to ammonia refrigeration systems are routine maintenance procedures. The potential for the release of ammonia during these procedures is cause for concern and the following guidelines have been developed in an effort to reduce the risk associated with these procedures, and to ensure compliance with the OH&S Act and Regulations.

  1. Personal protective equipment for the protection of respiratory system, skin and eyes must be worn while carrying out these procedures.
  2. Have a second person nearby observing the procedure and prepared to give assistance. Appropriate safety equipment must be readily accessible.
  3. Ensure that workers have received education and training in the Workplace Hazardous Materials Information System (WHMIS) requirements, Material Safety Data Sheet (MSDS) and exposure limits for anhydrous ammonia.
  4. Schedule these procedures for times when the facility is normally not in use or occupied by patrons. Keep a log of the quantity of oil drained and added to the system.
  5. Oil should not be drained while the refrigeration system is running. The refrigeration system should be shut down to allow the oil to settle.
  6. Prepare written procedures for the draining and addition of oil and post them in the machinery room. Each system has its own unique operating and installation characteristics and site specific procedures should be developed for each installation. A refrigeration contractor licensed by the Government Service Centre can help you develop appropriate procedures.
  7. Personnel responsible for the maintenance of the plant must be trained in these procedures. Check lists should be developed to guide personnel and provide a record of the work.
  8. An emergency response plan must be developed and emergency instructions, contact names, addresses and phone numbers posted in a conspicuous location.

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