Ask The Expert

Air Monitoring Under FSMA

The proposed FSMA rule on Preventive Controls for Human Food is making HACCP an integral part of all food manufacturing and mentions air as a potential source of contamination, but does not specify frequency. How can you take a risk-based approach in incorporating air monitoring into your HACCP plan? This week’s Ask the Expert focuses on Air Monitoring and Media Prep.

Q: An auditor recommended a specific air monitor. How do I decide if it’s really the right instrument for our facility? How do I start evaluating systems? How do I get up and running once I buy something?

A: To select the right air monitor you need to consider the needs of your facility, such as whether you need to test only ambient air or also compressed air. You also need to consider the different types of air sampling technologies, such as open versus closed systems, impaction versus centrifugal samplers and viable versus non-viable particle monitoring.

The first thing to consider is your facility. Does your facility use compressed air or compressed gas? Compressed air can be considered to be in direct or indirect product contact if it is used for mixing ingredients, cutting, sparging, drying, transporting ingredients through your processing systems, or in packaging. Thus, the microbiological content of the compressed air directly impacts product quality, and you will need to do compressed gas monitoring. Organisms in the environment can also impact your product, leading to the need for ambient air monitoring as well. Some air monitors are dedicated instruments that can only do either ambient or compressed gas testing. Others are designed primarily for ambient air monitoring but compressed gas adaptors are available as an accessory.

Another consideration is the mechanism by which air is collected and monitored. Many systems operate by impaction air sampling, in which air is drawn through a perforated lid to impact on the agar in a Petri dish. Another configuration is the centrifugal air sampler, in which the head of the air sampler spins and air impacts on a circular agar strip. To choose the right model for your facility, consider whether it is an open system (using a standard agar plate configuration) or a closed system with agar plates/strips that must be purchased from the instrument vendor. Here there is no right or wrong choice; it simply depends on a balance of the quality, ease of use, cost and variety of available media. You should also ask the vendor about the biological efficiency of their instrument. Biological efficiency considers the instrument’s ability to recover organisms. Another question to ask is the impact of using the instrument on the airflow in the facility – some are designed to be less disruptive than others.

In many facilities, viable air monitoring is enough. However, in facilities making product for sensitive populations – such as infant formulas or meal replacement beverages for the elderly or infirm – the manufacturing environment must be much cleaner, and air monitoring may also include non-viable particle monitoring. Here, you need to think about the sizes and number of particles you need to detect, whether you need a portable instrument, and any clean room regulations you may need to meet.

The final consideration in choosing equipment is ensuring the vendor will support you with adequate training and in the maintenance and repair of the instruments.

In addition to purchasing equipment, you need to decide where and how frequently to monitor. The proposed FSMA rule on Preventative Controls for Human Food seeks to make HACCP an integral part of all food manufacturing and mentions air as a potential source of contamination, but does not specify frequency. As a result, you must take a risk-based approach in incorporating air monitoring into your HACCP plan.

Q: We use a lot of culture media – both broth and agar. Our employees in our media kitchen hate breathing in all the dust and cleaning up the mess. We even have one staff member who has recently complained of health issues as a result of her time in the media kitchen. Is there anything we can do to make the job of media prep safer and easier?

A: Media prep is a messy job. Powdered media generates a lot of dust, which is messy and makes it hard to breathe. Making media can also lead to health issues – some media components may be toxic, while others can eventually lead to allergic reactions. There are products on the market that make media prep cleaner, safer and even a little faster.

The best alternative to the mess of powdered media is granulated media. The unique formulation of granulated media means much lower dust. That makes media prep less messy and cleanup is much easier. Lower dust also means less inhalation, making media prep less unpleasant and a lot safer by reducing the operator’s exposure to toxic or allergenic media components. Granulated media is also easier to handle – granulated media flows better, pours more easily, and falls right to the bottom of the flask instead of sticking to the sides of the vessel, and it goes into solution faster.

Safety of your employees is important, but you also want to make sure your media will provide you reliable recovery of organisms. This is not just a matter of the formulation of the media, but how reliably and reproducibly it is manufactured. Are the media components uniformly distributed in the bottle? And how does the manufacturer perform quality control testing? One sure way to know the media are of a high quality is if the vendor complies with ISO 11133. This ISO standard describes the quality assurance or culture media for microbiological analysis of food for humans and animals, as well as for water testing.

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