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Break Down The Standard: ASNZ3666.2 March 11, 2020




ASNZ3666.2 is one of two documents that are vital for any plant manager in a food factory to know.  

Let us break it down for you below.   


Required Actions
Operating and Maintenance Manual
Maintenance Reports


ASNZ3666 is a four-part standard on microbial control in air-handling and water systems of buildings. 


The objective of this standard is to ‘assist users in control of microorganisms in building systems, particularly those associated with Legionnaire’s disease, Pontiac fever, hypersensitivity pneumonitis and humidifier fever.’  That is simple enough, isn’t it?  Essentially, this standard states regulations that we must follow to keep our HVAC systems, and entire buildings, pathogen free. 


Among other roles, this standard applies to operating staff responsible for maintaining the air-handling systems of a building.

Perfect.  Exactly what we are looking for. 


So, the four parts.  


Part 1 refers to design, installation and commission. 
Part 2 refers to operations and maintenance.
Part 3 refers to performance-based maintenance of water-cooling systems. 
Part 4 refers to performance-based maintenance of air-handling systems. 


Each of these is important but understanding Part 2 is critical for plant managers.


ASNZ3666.2 Required Actions

Based on the regulation in this section, we have made a list of the required actions, based on their frequency. 


Every month:

  • Your air intakes and exhaust outlets should be inspected at least monthly and cleaned where necessary.
  • Any air filters should be inspected and cleaned or replaced if needed.
  • All coils, trays and sumps should be inspected and cleaned where necessary.
  • Condensate drains, tundishes and traps need to be checked, and drainage lines flushed clean.

Every three months:

  • Inspect fans for evidence of corrosion, wear of any flexible connections and drive belts, and other deterioration, and clean or repair where needed.

Every year:

  • Ductwork in the vicinity of moisture-producing equipment, such as condenser coils, should be inspected and cleaned where necessary.
  • Inspect terminal unit components, including coils; supply air outlets; return air and relief air grilles, and clean where necessary.



Operating and Maintenance Manual

Your site must also have an operating and maintenance manual that includes at least the following:

  • Physical details of your plant, equipment and systems, and pre-treatments carried out.
  • Recommendations on maintenance including water treatments and managements.
  • Manufacturer’s recommendations for checking, calibrating and maintaining all probes and sensors.
  • Recommended cleaning, disinfection and emergency decontamination procedures.
  • Start-up, operating and shut-down procedures
  • Particulars of the maintenance management program including plant servicing, cleaning schedules and replacement periods for equipment items, such as chemical dosing lines.


Maintenance Reports

In addition, you are required to keep up-to-date maintenance reports and service reports for all plant, equipment and systems that are the subject of this standard. 

These reports should include at least:

  • Date, item of plant, equipment or system and nature of service performed.
  • Results of periodic testing
  • Details of defects found, and rectification procedure undertaken.
  • Name of the person and company performing the service.

You need to keep this manual and your service records available for inspection by regulatory authority should they request it. 


As mentioned at the beginning, ASNZ366.2 is only one of two vital documents for you to understand.  Read our breakdown on the IRHACE HVAC Hygiene Best Practise Guideline here.  


If you have any questions on this standard, please ask below. 


Presco Environmental are able to set up and execute ASNZ3666.2 compliant HVAC Hygiene maintenance programs. For more information on this, please contact the author.



Matthew Prestidge, General Manager

About the Author

Matthew Prestidge is our General Manager and Senior Industrial Hygiene and Indoor Air Quality advisor.

Having spent the last 15 years creating more sustainable environments on industrial sites, Matthew has seen the good, the bad and the ugly and knows what is required to “clean up”.   

Would you like to discuss solutions to industrial cleaning issues?  
Matthew offers a free consultation and easy-to-implement advice on Industrial Hygiene and Indoor Air Quality for anyone in the New Zealand Food and Beverage industry. Contact him at matthew@presco.co.nz 



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