Chemical Disinfectants Storage and Shelf-life Stability

The Increasing Demand for Chemical Disinfectants

It is no surprise that since the COVID-19 pandemic, there has been a surge in the disinfectant market, as manufacturers produced more and more in order to meet the increasing demand. However, this increase in production and demand did not exempt manufacturers from still needing to adhere to regulations and guidelines outlined by the relevant regulatory bodies of where their products were to be sold. In the EU, the European Chemicals Agency (ECHA) require any biocidal product to adhere to Regulation (EU) 528/2012 (Biocidal Products Regulation (BPR)). In the US, the manufacture and sale of disinfectants are regulated by the Environmental Protection Agency (EPA). However, if the product is a liquid sterilant chemical, a high-level disinfectant intended for use on medical/dental devices, or a hand antiseptic (handwash or hand rub agent), then it is regulated by the Food and Drug Administration (FDA).

Shelf-life of Disinfectants

With a rise in demand for chemical disinfectants, manufacturers needed to find some way of getting their products to market faster, without compromising on the testing required to make the claims they wanted to. One example of data that is required by manufacturers of disinfectants is the shelf-life or expiration date that they are legally required to include in the labelling/packaging of the product. By doing so, they are certifying and reassuring users that their product will safely function as intended for use by that date. Shelf-life stability and expiration dates are determined through aging studies, in which the disinfectants are stored for a specific period under specific conditions and the physical and chemical properties of the disinfectant tested.

Accelerated Aging for Faster Results

Evidently, obtaining real-time data to establish that a disinfectant product is still safe to use after, for example, 2 years would mean having to delay getting the product to market while awaiting the results from the aging study. In order to get around this, manufacturers can opt to carry out accelerated aging studies using elevated temperature and/or humidity conditions which would speed up the normal aging process. This allows them to supply an accurate estimation of the shelf-life and see if the stability and functionality of their product deteriorates through such conditions.

For chemical disinfectants, the Therapeutic Goods Administration (TGA) of the Australian Government provide instructions on assessing the chemical stability and shelf-life of disinfectants. In this test, the disinfectant is isolated in a humidity chamber with elevated test temperature and tested for stability at the initial time point as well as at 3 other time points during the period of accelerated aging. The table below demonstrates the shelf-life prediction within these time intervals, as per the TGA guidelines:

This guideline can be a useful tool in establishing how long laboratory testing will take and what the corresponding shelf-life prediction will be. For example, if a chemical disinfectant is normally stored at a temperature of 25 °C, by storing the disinfectant within a chamber conditioned to 35 °C (+10 °C of the normal storage temperature) for a period of 3-months, the equivalent predicted shelf-life will be 1 year. If the chemical and physical properties of the product do not show any significant change after being stored in this way, then it provides an accurate estimate that the predicted shelf-life of a year is adequate.

During an aging study, the physical, chemical and antimicrobial properties of the disinfectant are assessed at specified time intervals:

Physical properties such as appearance, pH, boiling point, odour, and material compatibility are common characteristics that are assessed.
The 3 key points to be considered in chemical stability, according to the TGA, are:

1. Determining the active concentration of active substances with an appropriate detection assay, e.g. Fourier-Transform Infrared Spectroscopy (FTIR), or Gas Chromatography (GC).
2. Active concentration of active substance should not fall below 90% of the initial label claim at the end of shelf-life analysis.
3. All chemical test analysis should run in duplicate samples.

Antimicrobial stability is assessed via efficacy studies of which there are many international methods such as EN 13727, EN 13624, EN 16615, EN 13697, etc.

With experts in both chemistry and microbiology, we have both the facilities and knowledge to help manufacturers with their disinfectant claims. Our temperature- and humidity-controlled chambers can be used to store a large sample of products, and our experts can help develop the appropriate aging study for your needs to ensure all relevant chemical, physical and antimicrobial data is obtained.

Contact Us:

020 3813 0969 info@testlabsuk.com

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Written by Syeda Begum January 23rd 2025

Syeda is a chemist, holding a bachelor’s degree in Chemistry with Medicinal Chemistry and a research master’s degree in Chemistry. Her thesis titled ‘An Investigation of the Anion-Binding & Catalytic Abilities of Supramolecular Complexes’ displays her competency in coordination compounds – an area of chemistry that is utilised in many industries including biological and medical – as well as her skill in scientific communication and writing. Doing a research master’s has given Syeda the confidence and passion for laboratory work, being very capable of working on and developing research projects (testing methods, formulations, analysis, etc). For example, she has done testing for a university research group, which led to her name being included in their paper published in Angewandte Chemie – a high impact factor journal and one of the prime chemistry journals in the world. She hopes to utilise this experience and get involved with writing papers for any novel testing done at Test Labs.

Syeda is a keen learner and always interested in trying out different areas of science, which is shown in her past work experience assisting an engineering PhD student in the testing of lithium-ion batteries. This makes her perfect as a laboratory assistant for Test Labs where she is involved in all 3 areas of microbiology, chemistry, and materials science.