Good Laboratory Practice for Refrigeration and Freezing

Introduction

At Froilabo, we understand that it can sometimes be difficult to ensure 100% accuracy in your laboratory. That’s why we have put together this informative article to introduce you to the concept of Good Laboratory Practice (GLP) and the essential requirement to take good care of your laboratory products. Not only will this increase the longevity of your ULT freezer, but it will also ensure optimum performance, and the most accurate and reliable results.

What is Good Laboratory Practice (GLP)?

Good Laboratory Practice (GLP) is a quality assurance system that is used by laboratories and organisations to ensure the uniformity, consistency and reliability of non-clinical study and test data.

Good Laboratory Practice is essential for all non-clinical studies regulated by government agencies for the assessment of products in development for humans, animals and the environment. It is most commonly associated with the pharmaceutical industry, but also applies to applications such as food additives, food packaging, and medical devices.

Good Laboratory Practice for Refrigeration and Freezing

Good laboratory practice (GLP) documentation outlines standards to guide accurate temperature monitoring in the laboratory. GLP compliance when monitoring temperature is critical because temperature is a key contributing factor to safety, accuracy, and precision in the lab.

For example, accurate temperature monitoring in laboratories can prevent biological and chemical contamination of samples, which can render cultures unusable and produce incorrect experimental results. In the pharmaceutical industry, improper temperature monitoring can lead to low product integrity due to shortened shelf life and inaccurate pharmaceutical procedures.

The Importance of Freezer Maintenance and Cleaning

One of the main requirements for Good Laboratory Practice is that the laboratory equipment must be in proper working order. Regular freezer maintenance is therefore required at least once every month to ensure minimum energy consumption and optimum freezer performance.

Ultra Low Temperature Freezer Cleaning

Regular checks must be performed to ensure that there is no buildup of ice, frost or dust in the freezer. This is because ice, frost and dust accumulation can block the freezer’s filter and reduce internal space, which reduces the freezers ability to remove heat from inside the chamber and leads to higher energy use as more cold air will seep out. Removal of hard ice build-up is best done by switching off and defrosting the freezer, while transferring the contents to a spare freezer). Softer frost build up can be removed without defrosting by careful scraping.

The freezer air filter must also be checked regularly and kept clean, because if they are dirty and clogged up, the freezer motor will have to work harder and use more energy to stay at the required temperature. Air filters can usually be easily accessed at ground level on the front of the freezer, and can be easily removed for cleaning, either using a vacuum cleaner and/or washing with water. At the same time the heat exchanger fins will be accessible behind the filter, and should also be cleaned with a vacuum cleaner.

The door seals and gaskets must also be kept in good condition in order to prevent warm air from entering the chamber when the door is closed.

Regular cleaning of these components can reduce freezer energy consumption by up to 25%. If these elements are not regularly maintained, the freezer will experience increased wear and tear, which will lead to the production of inaccurate results and incompliance with GLP.

Freezer Door Usage

In order to maintain your freezer, you must avoid frequent opening and closing of the door, or leaving the door open for extended periods of time.

This is because it will prevent warm air and humidity from entering the freezer, which increases the heat load on the compressor and causes it to become prematurely damaged.

Correct Freezer Set Up

The correct set up of a freezer can further minimise stress on the freezer motor. It must be set up with at 20 – 30cm of clear surrounding space, so that the heat has enough room to escape and not cycle back into the freezer motor. Small rooms and hallway must be avoided because they make it harder to maintain the set temperature and can put additional stress on the lab’s HVAC system, leading to increased damage.

Dedicated spaces with abundant ‘natural ventilation’ have been constructed at The University of Edinburgh to house ultra low temperature freezers. These spaces have large louvred vents and fans which allow external air to be used either passively or actively to remove hot air from the freezers. If external air temperature rises above a certain level the louvres are closed and the room cooled with air conditioning. This significantly reduces the amount of air conditioning required to keep the air temperature of the freezer space at a level which allows the freezers to operate safely and with low energy consumption.

Performance Checking

Regular performance checking is Good Laboratory Practice because it allows us to analyse the condition of the freezer. This enables us to predict when the freezer may fail or produce inaccurate results, meaning that it needs servicing or replacing.

Performance checking is done through the comparison of the actual temperature with the set temperature. If the freezer cannot reach the set point, you will be able to hear the compressor running continuously, which is damaging and can lead to failure. Another indication is the time taken to return to a set point after opening the freezer door. If it is taking any longer than 15 minutes, the freezer is not performing efficiently and you may be obtaining inaccurate results.

If you are concerned about the performance of your freezer, Froilabo offer a full range of after sales services which may help.

Cleaning Froilabo’s ULT Freezers

At Froilabo, we produce a range of Low Temperature and Ultra Low Temperature Freezers which have been designed with Good Laboratory Practice and accuracy in mind.

With over 100 years of experience, all of our laboratory products are made and approved according to the standard EN60068-3-11, and our main priority is always the protection of the sample.

Our Evolution -86°C Freezer and our Trust -86°C Freezer come complete with the following range of features that prevent the buildup of contaminants and enable easy cleaning.

• Removable gates for quick cleaning out of the freezer
• A removable cassette filter that can be cleaned and easily interchanged
• Stainless steel inner bowl with rounded edges for easy cleaning
• Heated door seal and anti-frost formation

Knowing when to Replace a ULT Freezer

Despite this advice on Good Laboratory Practice and freezer maintenance, we understand that unfortunately every freezer will eventually reach the end of its lifespan at some point, with the average lifespan of a ULT freezer being 7-10 years when operating at -80°C.

Therefore, it is important for GLP to be aware of the following signs that your ULT freezer is no longer performing at its optimum ability and may need replacing:

• Average temperature observed is below the set temperature
• Significant rising and falling temperatures when the freezer doors have remained closed
• Gradual increase / decline in average temperature over any period

If you are experiencing any of these signs, you may have an aging compressor that will soon fail and is using more energy than necessary. Make sure to get in touch with a qualified engineer for assistance.

How Froilabo can help with Freezer Maintenance

At Froilabo, our team are here to help you comply with Good Laboratory Practice requirements. Our highly experienced service engineers are on hand to provide outstanding customer support and have a thorough understanding of a wide range of customer applications.

Our After-Sales Service Team can provide expert knowledge and guidance regarding the performance of your freezer, and our refrigeration technicians can assist with temperature control and advice relating to freezing, freeze-drying, cryogeny, climatic simulations and more.

We are also able to assist with any of the following freezer maintenance requirements:

• Repairs
• Cost estimate of repairs / retrofit / compliance upgrade
• Maintenance contract / prevention / curative

Get in Touch

Please don’t hesitate to get in touch with a member of our team today for further assistance regarding freezer maintenance and how you can comply with Good Laboratory Practice.

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