Most food and beverage plants filter their water, screen their ingredients, and sanitize their contact surfaces. Compressed air often gets less attention, even though it may be blowing across product, pushing it through a line, or sealing it into a package. Whatever the compressor and dryer leave behind in that air goes where the air goes. Point-of-use filtration is the last barrier before the air meets your product, and it deserves a place in your food safety plan.
What Is Actually in the Air
Compressed air carries three families of contaminants that ISO 8573-1:2010 classifies: particles, water, and oil. Particles can come from ambient air drawn into the compressor and from corroded piping. Water enters as vapor and condenses as the air cools. Oil can appear as aerosol, liquid, or vapor. The ISO standard's oil class covers total oil in all three forms, which matters because a coalescing filter handles aerosol and liquid, while vapor calls for adsorption media such as activated carbon.
Where the Air Meets Your Product
Direct contact is easy to spot: air that blows off crumbs or water before packaging, conveys powders and ingredients, inflates or flushes containers, or is injected into a product for mixing or aeration. Indirect contact is easier to miss: air that drives actuators, cleans equipment, or operates valves above an open line. A useful audit starts with a walk of the plant, listing every outlet and what sits downstream of it.
Each point can get a filter train sized to its risk: particulate and coalescing elements, plus adsorption or sterile-grade elements where oil vapor or microbial control is a concern. Filtering at the point of use matters because contaminants can still enter downstream of the dryer, through distribution piping, fittings, and hoses.
What the Rules and Guidelines Say
The FDA's current good manufacturing practice rule does address compressed air. 21 CFR 117.40(g) says compressed air or other gases mechanically introduced into food, or used to clean food-contact surfaces or equipment, "must be treated in such a way that food is not contaminated with unlawful indirect food additives." The rule does not name a filter type, a purity class, or a test method. Under the hazard analysis in 21 CFR 117.130, a facility identifies known or reasonably foreseeable biological, chemical, and physical hazards, and compressed air is one input your food safety team can evaluate for them.
For specifics, plants look to voluntary documents. ISO 8573-1:2010 defines purity classes. For reference, Class 2 for particles allows no more than 400,000 particles per cubic meter at 0.1 to 0.5 micron, 6,000 at 0.5 to 1 micron, and 100 at 1 to 5 micron. The British Compressed Air Society publishes Best Practice Guideline 102 for food and beverage grade compressed air, which industry sources describe as a voluntary code of practice. Those sources report that it targets ISO 8573-1:2010 [2:2:1] for air in direct contact with food and [2:4:2] for indirect contact, with purity verified at least twice a year. Neither ISO 8573 nor the BCAS guideline is a legal requirement. They become binding on your plant only if a customer, auditor, or GFSI-recognized certification scheme you hold requires them, so check your own audit scope before you adopt a target.
Keeping the Filters Honest
A filter that is saturated, bypassed, or overdue does little good. Treat the elements as a documented preventive task. Use the manufacturer's change interval and differential pressure guidance, record each change, and test the air at your points of use.
A practical starting sequence:
Map every point where compressed air contacts product, packaging, or food-contact surfaces.
Decide which outlets are direct and which are indirect, and document the target purity for each.
Test the air at those outlets and compare results with your targets.
Install or upgrade point-of-use filters where results fall short.
Set change intervals, record them, and review them after any maintenance.
Air and liquid filtration in a food plant can end up spread across several suppliers and part numbers. Our vendor consolidation guide is tailored to food and beverage plants that want compressed air, process liquid, and water filtration under one supply relationship. You can also see how we support your sector on our Food & Beverage industry page.
If compressed air touches your product, it belongs in your hazard analysis and your filter program. We have what you need to build that program, and we supply filtration matched to each point of use.
Sources: 21 CFR 117.40, Equipment and utensils (eCFR); 21 CFR 117.130, Hazard analysis (eCFR); ISO 8573-1:2010, Compressed air, Part 1: Contaminants and purity classes (ISO); BCAS Best Practice Guideline 102, Food and beverage grade compressed air