A Guide to Bioburden Testing: Why it’s Essential for Product Safety

What is bioburden testing?

Firstly, let’s consider what a bioburden is. A bioburden is the total number of viable microorganisms present within or on something. These microorganisms are usually yeast, fungi or bacteria.

Bioburden testing is used to measure the bioburden, which tells us the level of microbial contamination that is present.

What are the sources of bioburden contamination?

Bioburden contamination can come from a variety of sources, including:

• Raw materials
• The environment
• Equipment
• Packaging

Alongside the contaminants that occur naturally in the air, the environment, and raw materials, humans can often contaminate through equipment, surfaces, and packaging that are not sterilised. Following the correct hygiene procedures is therefore essential to avoid bioburden contamination.

The Risks of Bioburden Contamination

Contamination is a risk to product quality and safety. The specific risks depend on the industry that the product belongs to. We’ve included some examples for common industry issues below:

1) Pharmaceuticals and medical devices

Any contamination in these kinds of products poses a risk to health in the form of infections. Sepsis can be caused by non-sterile products that have been compromised by microorganisms.

2) Food and cosmetics

Skin irritation and allergic reactions can commonly be caused by food and beverage products, or cosmetic beauty items that are applied to the skin.

There can also be other related product issues such as not meeting regulatory standards such as bioburden limits or a reduction in product efficacy.

The Importance of Bioburden Testing for Safety

The key risks of bioburden contamination are product related infections and illnesses and product degradation. It is therefore of the utmost importance to test for the bioburden level of a product to ensure consumer safety and compliance with regulation.

Options for Testing

Direct plating

• Direct plating is where the sample is plated onto a culture media directly.
• It is most suitable for water-soluble materials with a moderate or high bioburden. This typically has a lower cost and is performed more quickly

Membrane filtration

• On the other hand, membrane filtration is where the sample is filtered through a membrane. The sample captures microbes and then is plated onto a culture media
• This is useful for non-water-soluble products with a low bioburden
• This has a higher sensitivity, but is generally slower and a higher cost
  

We would always recommend conducting bioburden testing, and we would recommend consulting with qualified professionals to assess the need within your application and industry.

For more information on automated testing, please contact Astech.