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Middlesex-London Health Unit

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Vaccine Storage and Handling

Cold chain refers to all of the materials, equipment, and procedures used to maintain vaccines in the required temperature range from the time of manufacture until administered. For most vaccines, the required temperature range is between +2oC and +8oC. 


Maintaining cold chain is critical to vaccine integrity. Vaccines are sensitive biological substances and failure to adhere to cold chain requirements may reduce their potency, resulting in lack of protection against vaccine preventable diseases and/or increased local reactions after administration. This loss of potency is cumulative, permanent and irreversible.

New Providers, Relocating, or Updating a Vaccine Refrigerator

Are you a new healthcare provider, organization or agency considering administering publicly funded vaccines? 

Are you relocating your practice and need to move your vaccine refrigerator? 

Do you need to transfer vaccine from an existing vaccine refrigerator to a new one? 

Read through this information and call the Health Unit (519-663-5317) to speak with a Public Health Nurse on the Vaccine Preventable Disease Team for support. 


Cold Chain Inspections

Public health units in Ontario are required to perform annual inspections of all premises that store publicly funded vaccines. 

What can you expect during your inspection?

During your inspection, a public health nurse from the Health Unit's Vaccine Preventable Disease Team will visit your office to:

  • ensure the proper management of vaccines,
  • review contingency planning,
  • provide education and resources, and
  • answer any questions your staff may have.

Vaccine Refrigerators and Organization

Healthcare providers storing publicly funded vaccines are required to have a dedicated refrigerator used for the storage of vaccines only.

Types of refrigerators

The chart below provides a comparison of the types of refrigerators and some general guidelines.

Purpose-built vaccine refrigerators Domestic (kitchen) and bar refrigerators
  • Preferred and recommended, especially when storing large vaccine inventories
  • Available in a variety of sizes
  • Experience fewer temperature fluctuations
  • Include quick temperature recovery systems
  • Nearly all internal space can be used to store vaccines
  • More costly to purchase, however the management is less demanding and they provide greater reassurance of proper vaccine storage
  • Not preferred, but can be used with the following modifications:
    • Vaccines cannot be stored on the door shelves or drawers due to temperature fluctuations in those areas
    • Empty shelves, doors and drawers should be filled with full water bottles
    • If using a bar fridge with a freezer compartment, the freezer must be defrosted when there is more than 1 cm (1/4 inch) of ice buildup
  • Prone to temperature fluctuations
  • Less expensive, however they may be more complicated to manage

Guidelines for all vaccine refrigerators

  • A vaccine refrigerator should be located:
    • in a well-ventilated room or area that is not accessible to the public and is locked at the end of the day
    • away from direct sunlight any external walls 
  • A vaccine refrigerator should only be used to store vaccine (no food or other specimens)
  • Ensure refrigerator is securely plugged into the electrical outlet and is not accidentally unplugged
  • Ensure the refrigerator door is shut after opening
  • Minimize the number of times the refrigerator door is opened
  • Keep icepacks in a freezer to use during vaccine transport. Icepacks can also be placed in the refrigerator to help maintain temperature within the recommended range during a power outage

Organizing the refrigerator

Maintaining a well-organized vaccine refrigerator plays an important role in:

  • preserving vaccine integrity (e.g. allowing ample air circulation, protecting vaccine from light),
  • keeping temperatures within the recommended range (e.g. minimizes how long the refrigerator door is open), and
  • preventing errors (e.g. administering an expired or wrong vaccine).
Guidance for refrigerator organization
  • Keep vaccines away from the refrigerator walls, vents and floor.
  • Do not store vaccines in the shelves or drawers of a domestic or bar refrigerator.
  • Organize vaccines by product type - baskets may be helpful to separate products.
  • Regularly check vaccine expiry dates and do not keep expired vaccine in the refrigerator.
    • Keeping a list of expiry dates may help with monitoring.
  • Always store vaccines in their original packaging to protect them from light and allow for easy identification.
  • Leave space between vaccine packages to allow for air circulation.
  • Use vaccines with the shortest expiry dates first.
  • Not all diluent products require refrigeration - however storing diluent with the vaccine product they are required for may prevent errors.
  • Any diluent products stored out of the fridge should be in labelled backets to ensure the correct diluent is used with the correct vaccine.


To prevent overcrowding and minimize waste in the evident of a cold chain incident, no more than a 1 month supply of vaccine should be stored in your vaccine refrigerator.

Temperature Monitoring

Each vaccine refrigerator and insulated cooler used for vaccine storage and transport must have its own temperature monitoring device such as a thermometer and/or data logger.


Vaccine refrigerator temperatures must be checked and documented twice daily when your site is open (at the beginning and end of the workday). One staff member should be assigned to this responsibility along with a back-up and all staff members should be trained in vaccine storage and handling. 

Temperature Monitoring Devices

Maximum-Minimum Thermometers

Data Loggers

Maximum-Minimum Thermometers

Maximum-minimum thermometers provide 3 readings:

  1. Current temperature; 
  2. Maximum temperature reached since the thermometer was last reset; and
  3. Minimum temperature since the thermometer was last reset. 

Maximum-minimum thermometers must include the following features to be used for vaccine monitoring:

  • Be capable of reading in and out temperatures (in/out thermometer)
  • Measure temperatures in increments of 0.1oC
  • Be able to reset/clear the maximum and minimum readings 

Healthcare providers can request a maximum-minimum thermometer at no cost from the Health Unit when ordering publicly funded vaccine. Alternatively, providers can source and purchase their own thermometers with enhanced features (e.g. with a larger display).

Guidance for setting up a maximum-minimum thermometer

  • The thermometer probe should be:
    • Placed inside an empty vaccine box (labelled "PROBE")
    • Positioned on the middle shelf of the refrigerator
    • Secured in place (i.e. with tape) to prevent from moving 
  • The display screen should be positioned outside of the refrigerator next to the temperature log book
  • Replace batteries every 6 months 

Steps for reading and recording refrigerator temperatures using a maximum-minimum:

  1. Write the DATE AND TIME in the vaccine temperature log book.
  2. Looking at the "OUT" temperatures on the thermometer displays, record the current, minimum, and maximum temperatures in the log book. 
  3. Sign your initials beneath the recording in the log book.
  4. Clear/reset the thermometer history.

Call the Health Unit (519-663-5317) as soon as possible if any of the temperature recordings are outside of the recommended +2⁰C to +8⁰C range.

Data Loggers

Data loggers are continuous temperature recording devices, which offer a historical record of refrigerator temperatures. This is particularly helpful for identifying duration if vaccine is exposed to temperatures outside of the recommended range (e.g. during a power outage).

Vaccine refrigerator temperatures must still be checked and recorded twice daily when using a data logger.

  • Maximum-minimum thermometers may be used in combination with data loggers for ease of monitoring and recording.
  • Temperature readings from a data logger usually require computer download. Temperatures should be printed out weekly and retained for 1 year, or until your annual inspection by the Health Unit.

Sample temperature log book

Download sample temperature log

Vaccine Temperature Log Book

Download Vaccine Temperature Log Book

Vaccine Transport and Temporary Storage

Cold chain must be maintained at all times, including during transportation and temporary storage. 

Equipment required for vaccine transport or *temporary storage:



  • Hard-sided, insulated coolers with lids
  • Icepacks or frozen gel packs
  • Temperature monitoring devices
  • Bubble wrap or packing material
  • Flexible refrigerated blankets stored in the fridge between 2oC and 8oC


*Temporary storage of vaccines may be necessary when cleaning a vaccine refrigerator or for emergency storage during a power outage.


Steps for preparing and packing an insulated cooler

An insulated cooler must be "conditioned" BEFORE it can be packed with vaccines. Conditioning involves ensuring the temperature inside the cooler is within the recommended range of 2oC and 8oC.

Step 1

  • Line the bottom of the cooler with 3 icepacks.

Step 2

  • If using a flexible refrigerated blanket, ensure it is pre-conditioned in the fridge (2⁰C to 8⁰C).
  • Lay the flexible refrigerated blanket on top of the icepacks and then add a layer of bubble wrap.
    • If not using a flexible refrigerated blanket, place 2 or 3 layers of bubble wrap on top of the icepacks.
  • Vaccines should never be in direct contact with ice or gel packs.

Step 3

  • Place the probe of the maximum-minimum thermometer on top of the bubble wrap in the centre of the cooler where the vaccine package will be held.

Step 4

  • Lay another layer of bubble wrap followed by a pre-conditioned refrigerated blanket on top of the probe.
    • If not using a refrigerated blanket, add 2 or 3 layers of bubble wrap and an additional ice or gel pack on top. Place more bubble wrap on top if necessary to fill any additional space.

Step 5

  • Close the cooler lid for approximately 20 to 30 minutes and monitor until the current temperature is stable between 2oC and 8oC.
  • Outdoor temperatures and length of time for transport/temporary storage may affect the cooler temperatures - adjust accordingly.
  • Vaccine can now be placed underneath the flexible refrigerated blanket and bubble wrap inside the cooler where the probe is located. 

Step 6

  • Close the cooler lid and clear/reset the maximum-minimum thermometer history. 
  • Vaccine can now be transported or stored in the insulated container while monitoring temperatures. 
  • Vaccine should not be transported in the trunk of a vehicle due to risk of extreme temperatures.
  • Icepacks may need to be replaced if being stored for longer than 2 hours. 

Temperatures of the insulated cooler should be recorded:

  • when the vaccine is first packed inside the cooler,
  • at least once each hour or each time the cooler is opened, whichever is more often, and
  • before the vaccine is removed at the destination or being returned to the vaccine refrigerator after temporary storage.

If temperatures are not maintained between 2oC and 8oC, call the Health Unit (519-663-5317) as soon as possible and mark vaccines as DO NOT USE until it can be determined if they are suitable for administration. 

Vaccine orders will not be released to couriers or office staff who do not bring appropriate packing materials and a conditioned insulated cooler to the Health Unit upon pick-up.

Packing an Insulated Cooler

Packing an Insulated Cooler for Vaccine Transport or Temporary Storage

COVID-19 Vaccine Specifications

While there are some similarities, the storage and handling of COVID-19 vaccines requires some modifications. 

COVID-19 vaccines are very fragile.

  • Pfizer BioNTech Comirnaty and Moderna Spikevax COVID-19 vaccines contain mRNA surrounded by a lipid bilayer.
  • This lipid bilayer is very fragile and can rupture easily with improper handling leading to wasted/ineffective vaccine. 
  • Take caution to ensure vials and syringes are not dropped.
  • During transport:
    • Label your insulated cooler as "Fragile: Handle with Care, Do Not Drop."
    • Secure vials in an upright position with extra bubble wrap.
    • Secure the cooler when travelling in a vehicle.

The recommended storage temperature and temperature recording guidelines for THAWED COVID-19 vaccines are the same as those listed above for other publicly funded vaccines. 

  • Note: It is recommended that the diluent for Pfizer-BioNTech Comirnaty COVID-19 vaccine be stored between +20oC and +25oC (do not refrigerate).

See the Ministry of Health's COVID-19 Vaccine Storage and Handling resource document for additional guidance.

Publicly Funded Vaccines - Orders and Returns

The Health Unit provides publicly funded vaccines to healthcare providers, organizations and agencies who have been pre-approved and inspected.

Publicly funded vaccines that have expired or need to be wasted must be returned to the Health Unit for proper disposal. 

Instructions on applying for ordering and for returning vaccines can be found here

Cold Chain Incidents

A cold chain incident occurs when vaccine is exposed to temperatures outside the recommended range of 2oC to 8oC.

Steps to take in the event of a cold chain incident

Step 1

  • Segregate the vaccines by placing the affected products in a bag marked "DO NOT USE."
  • Keep the bag in the vaccine refrigerator. Do not use or discard any of the vaccines until the Health Unit has assessed whether any of the vaccines can still be used. 

Step 2 

  • Call the Health Unit (519-663-5317) as soon as possible to report the incident. 
  • Have the following information ready when calling:
    • Temperature logs
    • A list of the affected vaccines, including
      • product names, lot numbers, expiry dates, and quantities 
      • whether any multi-dose vials have been previously punctured
      • whether any of the vaccines have been exposed to a previous incident (e.g. are "red-dotted")
  • You will be required to submit the above information to the Health Unit and assist with completing the Cold Chain Incident Exposure/Wastage Report form.

Step 3 

  • Await further instruction from the Health Unit:
    • If it is determined that the vaccines remain suitable for use, mark them with a red dot to indicate that they have been involved in a cold chain incident. This is important since exposure time is calculated cumulatively.
    • If the vaccines are unsuitable for use, remove them from the fridge IMMEDIATELY and return them to the Health Unit with the Vaccine Return Form

Troubleshooting when vaccine refrigerator temperatures are outside of the recommended range:

  • Is the temperature monitoring device is working?
    • is the probe correctly placed? 
    • does the device need new batteries?
    • are the OUT temperatures being read on the maximum-minimum thermometer? 
  • Is the refrigerator is plugged in?
  • Has the temperature of the room changed dramatically?
  • Is the refrigerator door closed/was it left opened? Is the door sealing properly?
  • Is anything blocking the air flow of the refrigerator? 
  • If unable to determine the cause, sites may need to contact a technician to preform maintenance or repairs.  

Contingency Planning

Healthcare providers, organizations and agencies should develop a contingency plan in the event of a vaccine refrigerator malfunction or power outage. Contingency plans may include:

  • making arrangements in advance with an alternate storage site (e.g. another office/pharmacy)
  • using insulated containers and packing materials
  • in the event of an outage where power is expected to be restored within several hours - add ice packs to the refrigerator and keep the door closed

Temperatures should be monitored and recorded while your contingency plan is in effect. Call the Health Unit (519-663-5317) as soon as possible if the vaccine is exposed to temperatures outside of the recommended range. 


Date of creation: February 27, 2013
Last modified on: April 16, 2024


1Ministry of Health and Long-Term Care – Vaccine Storage and Handling Protocol Retrieved from
2Ministry of Health – Vaccine Storage and Handling Guidelines Retrieved from
3Ministry of Health - COVID-19 Vaccine Storage and Handling Guidance Retrieved from